WO2023040966A1 - 一种保温隔热材料及其制备方法和应用 - Google Patents

一种保温隔热材料及其制备方法和应用 Download PDF

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WO2023040966A1
WO2023040966A1 PCT/CN2022/119048 CN2022119048W WO2023040966A1 WO 2023040966 A1 WO2023040966 A1 WO 2023040966A1 CN 2022119048 W CN2022119048 W CN 2022119048W WO 2023040966 A1 WO2023040966 A1 WO 2023040966A1
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thermal insulation
insulation material
preparation
rare earth
material according
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PCT/CN2022/119048
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English (en)
French (fr)
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余煜玺
黄聿娟
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中科润资(重庆)节能科技有限公司
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Priority claimed from CN202111091769.5A external-priority patent/CN113668139A/zh
Priority claimed from CN202111091766.1A external-priority patent/CN113651334A/zh
Priority claimed from PCT/CN2022/088414 external-priority patent/WO2023201690A1/zh
Priority claimed from PCT/CN2022/088412 external-priority patent/WO2023201688A1/zh
Application filed by 中科润资(重庆)节能科技有限公司 filed Critical 中科润资(重庆)节能科技有限公司
Publication of WO2023040966A1 publication Critical patent/WO2023040966A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
    • C01B33/155—Preparation of hydroorganogels or organogels
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
    • C01B33/157—After-treatment of gels
    • C01B33/158—Purification; Drying; Dehydrating
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4282—Addition polymers
    • D04H1/4309—Polyvinyl alcohol
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
    • D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
    • D04H1/728—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged by electro-spinning

Definitions

  • the invention belongs to the field of thermal insulation materials, and relates to a thermal insulation material and a preparation method and application thereof.
  • Inorganic materials especially ceramic materials, have the advantages of high temperature resistance, corrosion resistance, and good insulation. They have certain application advantages as high-temperature heat insulation materials on hypervelocity aircraft.
  • Silica SiO2 is a non-toxic, odorless and non-polluting inorganic non-metallic material widely distributed in nature. It has good temperature resistance, excellent corrosion resistance, good thermal conductivity, good insulation and stable chemical properties. Features, are widely used in many fields.
  • the purpose of the present invention is to provide a thermal insulation material and its preparation method and application that can solve the defects of the existing ceramic-based thermal insulation materials in the aerospace field, such as high brittleness, difficult installation and maintenance, and unsuitability for high working temperature.
  • the diameter of the fiber is nanoscale, which endows the material with flexibility, and the unique large porosity and large specific surface area in the material make the material have a lower thermal conductivity.
  • the invention also provides a hydrophobically modified thermal insulation material, which has the prospect of being applied to high-temperature and humid environments.
  • the invention also provides a preparation method of the thermal insulation material. The method has the advantages of simple process, easy-to-obtain raw materials, can reduce production costs, and has the prospect of mass production.
  • the present invention provides the following technical solutions:
  • a kind of thermal insulation material is a kind of membrane material or felt-like material, is a kind of flexible material;
  • the described thermal insulation material comprise SiO 2 three-dimensional interpenetrating network that ceramic nanofiber forms structure, the average diameter of the fibers is 200nm-350nm.
  • the thermal insulation material has at least one of the following properties:
  • High temperature resistance can be used at 800 ⁇ 1200 °C;
  • the density (g/cm) is between 0.08 and 0.20;
  • the tensile mechanical strength is 0.5-4.5MPa
  • the thermal insulation material further includes a sunscreen.
  • the fiber is a nano hollow fiber having a hollow structure.
  • the present invention also provides a method for preparing the thermal insulation material, the method comprising the following steps:
  • SiO 2 precursor spinnable sol mix high molecular polymer solution and silica sol in step 1), obtain SiO 2 precursor spinnable sol;
  • the weight ratio of described high molecular polymer solution and silica sol is 1: (1 ⁇ 6);
  • the SiO 2 precursor spinnable sol in step 2) is prepared by electrospinning to obtain a film-like material or felt material, and after removing static electricity, it is calcined to obtain the thermal insulation material.
  • described method also comprises the following steps:
  • thermo insulation material with hydrophobic properties use hydrophobic modifier to carry out hydrophobic modification treatment on the thermal insulation material in step 3), and dry to obtain the thermal insulation material with hydrophobic properties.
  • the present invention also provides a thermal insulation composite material, which is a composite of the thermal insulation material and silica airgel or rare earth doped silica airgel.
  • the composite material is a composite of the above thermal insulation material and silica airgel, the composite includes a skeleton and a filler, the thermal insulation material serves as a skeleton, and the silica airgel serves as filler.
  • the composite material is a composite of the above thermal insulation material and rare earth doped silica airgel, the composite includes a skeleton and a filler, the thermal insulation material serves as a skeleton, and the rare earth doped with two Silica airgel as filler.
  • the aerogel further includes silicon micropowder.
  • the airgel further includes an opacifying agent.
  • the present invention also provides a method for preparing the thermal insulation composite material, the method comprising the following steps:
  • silica sol prepare silica sol by mixing silicon source, water, and alcohol solvent;
  • SiO 2 precursor spinnable sol mix the polymer solution and silica sol in step S3-1 to obtain SiO 2 precursor spinnable sol;
  • Preparing fiber preforms preparing the SiO2 precursor spinnable sol in step S3-2 by electrospinning to obtain film-like materials or felt-like materials, after removing static electricity, calcining to obtain fiber preforms;
  • Modification of the fiber preform using a hydrophobic modifier to perform hydrophobic modification treatment on the fiber preform in step S3, and drying to obtain a fiber preform with hydrophobic properties;
  • step S6 Drying: drying the gel in step S5 to obtain the thermal insulation composite material.
  • the present invention also provides the application of the thermal insulation material or the thermal insulation composite material for thermal insulation in a high temperature and humid environment.
  • the present invention also provides a smoke prevention and exhaust air duct, the smoke prevention and exhaust air duct includes a metal pipe, the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer, the heat shielding layer includes a heat insulating layer, and the heat insulating layer It includes the thermal insulation material or the thermal insulation composite material.
  • the present invention has the following significant advantages:
  • the present invention uses PVA as an auxiliary agent, mixes a polymer solvent and silica sol as a precursor sol, and prepares a thermal insulation material with a special porosity through a sol-gel electrospinning method.
  • the preparation process is simple and the raw materials are easy to obtain , Can reduce production cost, has the prospect of mass production;
  • the thermal insulation material prepared by the present invention has the advantages of thin and controllable thickness, and good mechanical strength, can be folded and bent at will, and it also has good tensile strength (for example, the tensile strength can be as high as 4.145MPa) ;
  • the thermal insulation material prepared by the present invention can be applied at 800-1200°C without changing its fiber morphology and structure, and has low thermal conductivity, so it can be used as a high-temperature-resistant thermal insulation material in high-temperature fields;
  • the hydrophobically modified thermal insulation material prepared by the present invention has hydrophobic properties, combined with its high temperature resistance performance, it has potential applications in high temperature and humid environments.
  • Figure 1 is a flow chart of the preparation of SiO2 ceramic nanofiber membrane.
  • FIG. 2 is a SEM image of the SiO2 ceramic nanofiber membrane prepared in Example 1.
  • Fig. 3 is the TG curve of the SiO 2 ceramic nanofiber membrane prepared in Example 1.
  • Figure 4 is the hydrophobically modified SiO2 ceramic nanofiber membrane prepared in Example 1.
  • Fig. 5 is an electron microscope image of the nano hollow fiber of the present invention.
  • Fig. 6 is a schematic diagram of the coaxial trocar head of the present invention.
  • Fig. 7 is a schematic diagram of the smoke prevention and exhaust duct of the present invention.
  • Fig. 8 is a schematic diagram of the quick disassembly and assembly air duct of the present invention.
  • Fig. 9 is a schematic diagram of the heat shielding layer of the present invention.
  • Fig. 10 is a schematic diagram of the heat-insulating layer wrapping the high-temperature-resistant protective layer of the present invention.
  • Fig. 11 is a schematic diagram of the morphology of the high-temperature expansion layer of the present invention at different temperatures.
  • Fig. 12 is a schematic structural view of the smoke exhaust duct of the present invention.
  • the present invention provides a thermal insulation material, which is a film material or a felt material, and is a flexible material; the thermal insulation material includes a three-dimensional structure composed of SiO2 ceramic nanofibers.
  • the interpenetrating network structure, the average diameter of the fiber is 200nm-350nm.
  • the average diameter of the fibers is, for example, 200nm, 205nm, 240nm, 245nm, 280nm, 281nm, 282nm, 283nm, 284nm, 285nm, 286nm, 287nm, 288nm, 289nm, 290nm, 300nm, 310nm , 320nm, 330nm, 340nm or 350nm.
  • the standard deviation of the average diameter of the fibers is 30nm-70nm, such as 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm or 70nm.
  • the surface of the thermal insulation material has hydrophobic functional groups.
  • the thermal insulation material when the thermal insulation material is a film-like material, its thickness is 0.5 mm to 5.0 mm, specifically 0.5 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.3 mm, 1.5mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, 3.4mm, 3.5mm, 3.8mm, 4.0mm, 4.2mm, 4.5mm or 5.0mm; when the thermal insulation material is In the case of a felt material, its thickness is 0.5 cm to 5 cm, specifically 0.5 cm, 1 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm or 5 cm.
  • the thermal insulation material is resistant to high temperature, specifically, it can be used at 800-1200°C.
  • the density (g/cm) of the thermal insulation material is between 0.08 and 0.20, such as 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.20.
  • the thermal insulation material has a low thermal conductivity, specifically, its thermal conductivity is 0.04-0.08W/mK, for example, 0.04, 0.041, 0.04141, 0.042, 0.044, 0.05 , 0.06, 0.07, 0.072, 0.074, 0.07416, 0.076, 0.078, 0.08W/mK.
  • the tensile mechanical strength of the thermal insulation material is 0.5-4.5 MPa, specifically, it can be 0.5, 0.51, 0.55, 0.6, 0.8, 1.0, 2.0, 3.0, 3.5, 4.0 , 4.1, 4.145, 4.2, 4.3, 4.4 or 4.5MPa.
  • the thermal insulation material further includes an opacifying agent, in order to enhance the thermal insulation performance under high temperature conditions.
  • the opacifying agent may include at least one of titanium dioxide, carbon black, SiC, potassium hexatitanate, ZrO 2 and the like.
  • titanium dioxide may be anatase titanium dioxide.
  • titanium dioxide can be fluorine-doped or nitrogen-doped titanium dioxide nanoparticles.
  • the fiber is a hollow nanofiber with a hollow structure.
  • the present invention also provides a method for preparing the above-mentioned thermal insulation material, the method comprising the following steps:
  • SiO 2 precursor spinnable sol mix high molecular polymer solution and silica sol in step 1), obtain SiO 2 precursor spinnable sol;
  • the weight ratio of described high molecular polymer solution and silica sol is 1: (1 ⁇ 6);
  • the SiO 2 precursor spinnable sol in step 2) is prepared by electrospinning to obtain a film-like material or felt material, and after removing static electricity, it is calcined to obtain the thermal insulation material.
  • described method also comprises the following steps:
  • thermo insulation material with hydrophobic properties the thermal insulation material in step 3) is subjected to hydrophobic modification treatment with a hydrophobic modifier, and dried to obtain the thermal insulation material with hydrophobic properties.
  • the template polymer is, for example, selected from PVA powder; specifically, the PVA powder can be 1788 type.
  • the mass fraction of the high molecular polymer solution may be 10%-12%.
  • the water in step 1), can be ultrapure water.
  • the prepared polymer solution in step 1), can be stirred for 6h-8h to completely dissolve the PVA powder in water.
  • the pH value of the silica sol is 8.5-9.0, the concentration is 2-4mol/L, the mass fraction is 15-25%, and the density is 0.957g/cm 3 .
  • the mass ratio of the polymer solution to the silica sol can be, for example, 1:1, 1:2, 1:3, 1:4, 1:5 or 1:6.
  • the SiO 2 precursor spinnable sol is obtained by stirring after mixing; specifically, the stirring time may be 0.5h-3h.
  • the inner diameter of the electrospinning needle is 0.50 mm to 0.60 mm; specifically, the parameters of the electrospinning can be: relative humidity 25% to 45% , the extrusion speed is 0.9 ⁇ 1.5ml/h, the voltage is 12 ⁇ 16kv, the distance between the receiving device and the spinneret is 8 ⁇ 10cm, the spinning time is 1h ⁇ 4h, the metal drum is used as the receiving device, and the drum speed is 40 ⁇ 70r/min.
  • step 3 place in an oven to remove static electricity, specifically, place in an oven at 40-50° C. for 30 minutes to 1 hour to remove static electricity.
  • the calcination procedure may be: heating from room temperature to 800°C at a heating rate of 5°C/min, and holding at 800°C for 1 hour.
  • step 3 it can be calcined at 900-1300°C, and the calcining program is controlled as follows: from room temperature to 900-1300°C, the heating rate is 5°C/min, and at the highest Keep the temperature for 1h.
  • the hydrophobic modifier is prepared by the following method: the silane coupling agent and ethanol are mixed according to the mass ratio of 3: (8 ⁇ 12), and 0.5 ⁇ 2wt % dilute nitric acid to adjust the pH value of the mixed solution to about 3, stir for 1h to 2h to hydrolyze it to obtain a hydrophobic modifier;
  • the silane coupling agent can be selected from KH-570, KH-550, KH-560, Chlorotrimethylsilane, Tridecafluorooctyltriethoxysilane, Heptadecafluorodecyltriethoxysilane, Tridecylfluorooctyltrimethoxysilane, Heptadecafluorodecyltrimethoxysilane, Acetoxy Benzyltrimethylsilane, benzyldimethylchlorosilane, benzyltrichlorosilane,
  • the hydrophobic modification is carried out in a vacuum drying oven; specifically, the temperature of the drying oven may be 40-80°C, and the treatment time is 4h-8h.
  • the drying is performed in an oven; specifically, it is performed under an air atmosphere.
  • the purpose of drying is to remove residual solvent.
  • the drying temperature is 50-70°C, and the drying time is 6h-10h.
  • the preparation method of the above-mentioned thermal insulation material specifically includes the following steps:
  • Step 1 preparing a polymer solution, which is prepared from a template polymer and water;
  • Step 2 Prepare SiO 2 precursor spinnable sol, mix and stir the above polymer solution with silica sol to obtain SiO 2 precursor spinnable sol;
  • Step 3 Electrospinning the SiO2 precursor spinnable sol obtained above to obtain a template polymer/ SiO2 composite ceramic nanofiber membrane, and place it in an oven to remove residual static electricity;
  • Step 4 placing the prepared PVA/ SiO2 composite ceramic nanofiber membrane in a box furnace for calcining to remove organic matter, and obtaining a flexible SiO2 ceramic nanofiber membrane;
  • Step 5 Mix the silane coupling agent and ethanol according to a certain mass ratio, and add dilute nitric acid to make it hydrolyze to prepare a hydrophobic modifier;
  • Step 6 Soak the SiO2 ceramic nanofiber membrane in the hydrophobic modifier
  • Step 7 Take out the wetted SiO2 ceramic nanofibers in step 6 and put them into a vacuum oven for vacuum drying to remove the solvent.
  • the template polymer is selected from PVA powder.
  • the water is ultrapure water.
  • the silica sol is alkaline silica sol, neutral silica sol or acidic silica sol.
  • step 2 the polymer solution and silica sol are mixed according to a mass ratio of 1:(1-6), and stirred for 0.5h-3h to obtain a precursor sol.
  • an opacifying agent may be added to the silica sol for the purpose of enhancing the temperature insulation performance under high temperature conditions.
  • the opacifying agent may include at least one of titanium dioxide, carbon black, SiC, potassium hexatitanate, ZrO 2 and the like.
  • titanium dioxide may be anatase titanium dioxide.
  • the titanium dioxide may be fluorine-doped or nitrogen-doped titanium dioxide nanoparticles, and the purpose of adding such titanium dioxide is to enhance the shading effect of infrared radiation.
  • rare earth compounds can be added to the silica sol, and the rare earth compounds are rare earth metal salts or rare earth metal oxides, such as yttrium metal salts, scandium metal salts, and La series metal salts. (specifically neodymium metal salt, ytterbium metal salt), yttrium metal oxide, scandium metal oxide, La-based metal oxide (specifically neodymium metal oxide, ytterbium metal oxide) and the like. Also for example, the rare earth compound is a combination of two or more, specifically, a combination of yttrium metal salt and scandium metal salt.
  • the rare earth compound is a combination of two or more, specifically, a combination of yttrium metal salt and scandium metal salt.
  • the rare earth compound is at least one of rare earth metal nitrate, rare earth metal oxalate, and rare earth metal carbonate.
  • it is rare earth metal nitrate hydrate, for example, the rare earth compound is Y(NO 3 ) 3 ⁇ 4H 2 O, Sc(NO 3 ) 3 ⁇ 6H 2 O, Nd(NO 3 ) 3 ⁇ 6H 2 O, Yb( At least one of NO 3 ) 3 ⁇ 5H 2 O and the like.
  • Nitrates, oxalates or carbonates are used in the present invention.
  • step 3 a 10ml syringe is used in the electrospinning, the inner diameter of the electrospinning needle is 0.50 mm to 0.60 mm, the electrospinning parameters are: relative humidity 25% to 45%, extrusion
  • the speed is 0.9 ⁇ 1.2ml/h
  • the voltage is 12 ⁇ 16kv
  • the distance between the receiving device and the spinneret is 8 ⁇ 10cm
  • the spinning time is 1h ⁇ 4h
  • the metal drum is used as the receiving device
  • the drum speed is 40 ⁇ 70r /min.
  • the needle used for electrospinning is a coaxial sleeve needle
  • the coaxial sleeve needle includes an inner layer needle and an outer layer needle
  • the inner layer needle sleeve is inside the outer layer needle, and remain coaxial.
  • the high molecular polymer solution flows through the needles of the inner layer
  • the SiO 2 precursor spinnable sol flows between the needles of the inner layer and the outer layer of needles.
  • Nano hollow fiber with hollow structure can be obtained through the coaxial sleeve needle.
  • the coaxial trocar head is shown in FIG. 6 .
  • step 3 the prepared PVA/SiO 2 ceramic nanofiber membrane is placed in an oven at 40-50°C for 0.5h-2h to remove static electricity.
  • the calcination procedure for removing organic matter in step 4 is: heating from room temperature to 800° C. at a heating rate of 5° C./min, and holding at 800° C. for 1 hour.
  • the SiO2 ceramic nanofiber membrane was calcined at 900-1300°C, and the calcination program was controlled as follows: from room temperature to 900-1300°C, the heating rate was 5°C/min, and the temperature was kept at the highest temperature for 1h.
  • the silane coupling agent in the step 5 is selected from KH-550, KH-560, KH-570, chlorotrimethylsilane, tridecafluorooctyltriethoxysilane, Heptafluorodecyltriethoxysilane, Tridecafluorooctyltrimethoxysilane, Heptadecafluorodecyltrimethoxysilane, Acetoxytrimethylsilane, Benzyldimethylchlorosilane, Benzyltrichlorosilane Silane, benzyltriethoxysilane, tert-butyltrimethylchlorosilane, dichloroisobutylmethylsilane, n-butyltrichlorosilane, cycloethyltrichlorosilane, 3-chlorocyclopentylsilane or dibutyl One of the base silicon dichlorides.
  • the silane coupling agent and the solvent are mixed according to a mass ratio of 1:(1-5), and the pH value of the mixed solution is adjusted to about 3 with 1 wt% dilute nitric acid, and stirred for 2 hours to make it hydrolysis to obtain a hydrophobic modifier;
  • the solvent can be selected from n-hexane, ethanol, tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, chloroform, dichloromethane, methanol, At least one of carbon tetrachloride, pyrimidine, xylene, cyclohexane, methyl ethyl ketone or methyl acetate.
  • step 6 the modification is performed in an oven, specifically, the temperature of the oven is 60° C., and the treatment time is 6 hours to 8 hours.
  • the drying temperature is 50-70°C, and the drying time is 6h-10h.
  • the present invention also provides a thermal insulation composite material, which is a composite of the above thermal insulation material and silica aerogel or rare earth doped silica aerogel.
  • the composite material is a composite of the above thermal insulation material and silica airgel; specifically, the composite includes a skeleton and a filler, and the thermal insulation material serves as a skeleton, so The above-mentioned silica airgel is used as filler.
  • the composite material is a composite of the above-mentioned thermal insulation material and rare earth doped silica airgel; specifically, the composite includes a skeleton and a filler, and the thermal insulation material serves as framework, the rare earth-doped silica airgel acts as a filler.
  • the aerogel further includes silicon micropowder.
  • the particle size of the silicon micropowder ranges from 600 mesh to 1500 mesh.
  • the silicon micropowder may be crystalline silica powder, or amorphous (amorphous) silica powder.
  • Amorphous silicon powder is a silicon dioxide material, and there will be a phenomenon of volume change caused by the transformation of crystal form under temperature change.
  • the volume expansion of amorphous silicon micropowder will suppress and reduce the internal stress when the heat insulation material experiences high temperature, thereby reducing the structural change inside the heat insulation material and stabilizing its heat insulation performance under high temperature conditions.
  • Microsilica powder will react and transform to mullite at high temperature and contain aluminum elements. Mullite is an excellent refractory material, so the addition of microsilica powder further improves the high temperature resistance of thermal insulation materials.
  • the particle size of amorphous silicon micropowder is 800-8000 mesh, 1000-2000 mesh, 2000-3000 mesh, 3000-4000 mesh, 4000-5000 mesh, 5000-6000 mesh, 6000-7000 mesh, 7000-8000 mesh Mesh, 1000-1500 mesh, 1500-3000 mesh, or 10-800nm, 10-100nm, 50-200nm, 100-400nm, 300-800nm.
  • the preferred particle size is 800-1000 mesh, 1000-1200 mesh, 1000-3000 mesh.
  • the addition amount of silicon micropowder is 3-25wt%, 1-10wt%, 3-15wt%, 5-20wt%, 5-25wt%, 10-25wt%, the preferred addition amount is 2-10wt%, 3- 8wt%, 3-6wt%.
  • the addition amount of the amorphous silicon micropowder is 1-20wt%, 1-15wt%, 2-10wt%, 3-8wt%.
  • the preferred particle size can better promote the combination of silicon, aluminum and oxygen bonds, making the structure more stable.
  • the optimal amount of addition can better improve the ability of the material to resist shrinkage at high temperatures while maintaining high thermal insulation performance and mechanical strength.
  • the aerogel further includes a sunscreen agent.
  • the opacifying agent may include at least one of titanium dioxide, carbon black, SiC, potassium hexatitanate, ZrO 2 and the like.
  • titanium dioxide may be anatase titanium dioxide.
  • titanium dioxide can be fluorine-doped or nitrogen-doped titanium dioxide nanoparticles.
  • the present invention also provides a method for preparing the above thermal insulation composite material, the method comprising the following steps:
  • silica sol prepare silica sol by mixing silicon source, water, and alcohol solvent;
  • SiO 2 precursor spinnable sol mix the polymer solution and silica sol in step S3-1 to obtain SiO 2 precursor spinnable sol;
  • Preparing fiber preforms preparing the SiO2 precursor spinnable sol in step S3-2 by electrospinning to obtain film-like materials or felt-like materials, after removing static electricity, calcining to obtain fiber preforms;
  • Modification of the fiber preform using a hydrophobic modifier to perform hydrophobic modification treatment on the fiber preform in step S3, and drying to obtain a fiber preform with hydrophobic properties;
  • step S6 Drying: drying the gel in step S5 to obtain the thermal insulation composite material.
  • step S1 specifically includes: preparing silica sol by mixing silicon source, water, alcohol solvent, and silicon micropowder.
  • a hydrolysis catalyst can be added to the silica sol to accelerate the hydrolysis of the silicon source and obtain the silica sol faster.
  • the silicon source can be selected from sodium silicate, ethyl orthosilicate, methyl orthosilicate, tetrapropoxysilane, tetrabutoxysilane, dimethyldimethoxysilane or dimethyldimethoxysilane Ethoxysilanes or combinations thereof.
  • the microsilica powder has the above-mentioned definition.
  • the hydrolysis catalyst can be selected from hydrochloric acid, oxalic acid, nitric acid, sulfuric acid, phosphoric acid or a combination thereof.
  • the alcohol solvent may be methanol, ethanol or a combination thereof.
  • an opacifying agent may also be added to the silica sol in step S1, in order to enhance the temperature insulation performance under high temperature conditions.
  • the opacifying agent includes at least one of titanium dioxide, carbon black, SiC, potassium hexatitanate, ZrO 2 and the like.
  • titanium dioxide may be anatase titanium dioxide.
  • the titanium dioxide may be fluorine-doped or nitrogen-doped titanium dioxide nanoparticles, and the purpose of selecting such titanium dioxide is to enhance the shading effect of infrared radiation.
  • rare earth compounds can also be added to the silica sol in step S1, and the rare earth compounds are rare earth metal salts or rare earth metal oxides, such as yttrium metal salts, scandium metal salts, La series metal salts ( Specifically, at least one of neodymium metal salts, ytterbium metal salts), yttrium metal oxides, scandium metal oxides, La-based metal oxides (specifically neodymium metal oxides, ytterbium metal oxides), and the like. Also for example, the rare earth compound is a combination of two or more, specifically, a combination of yttrium metal salt and scandium metal salt.
  • the rare earth compound is a combination of two or more, specifically, a combination of yttrium metal salt and scandium metal salt.
  • the rare earth compound is at least one of rare earth metal nitrate, rare earth metal oxalate, and rare earth metal carbonate.
  • it is rare earth metal nitrate hydrate, for example, the rare earth compound is Y(NO 3 ) 3 ⁇ 4H 2 O, Sc(NO 3 ) 3 ⁇ 6H 2 O, Nd(NO 3 ) 3 ⁇ 6H 2 O, Yb( At least one of NO 3 ) 3 ⁇ 5H 2 O and the like.
  • Nitrates, oxalates or carbonates are used in the present invention.
  • the introduction of ions further realizes the control of the content of halide ions in the airgel.
  • the specific process of preparing the rare earth compound solution includes: dissolving the rare earth compound in water, heating and reacting, and cooling to room temperature to obtain the rare earth compound solution.
  • the rare earth compound is a rare earth metal salt or a rare earth metal oxide, such as yttrium metal salt, scandium metal salt, La series metal salt (specifically neodymium metal salt, ytterbium metal salt ), yttrium metal oxide, scandium metal oxide, La-based metal oxide (specifically neodymium metal oxide, ytterbium metal oxide) and the like.
  • the rare earth compound is a combination of two or more, specifically, a combination of yttrium metal salt and scandium metal salt.
  • the rare earth compound is at least one of rare earth metal nitrate, rare earth metal oxalate, and rare earth metal carbonate.
  • it is rare earth metal nitrate hydrate, for example, the rare earth compound is Y(NO 3 ) 3 ⁇ 4H 2 O, Sc(NO 3 ) 3 ⁇ 6H 2 O, Nd(NO 3 ) 3 ⁇ 6H 2 O, Yb( At least one of NO 3 ) 3 ⁇ 5H 2 O and the like.
  • nitrates, oxalates or carbonates are used to avoid the introduction of halide ions, and further realize the content control of halide ions in the airgel.
  • a water bath is used for heating.
  • the heating temperature may be 40°C-60°C, for example, 45-50°C; the heating time may be 20min-60min, for example, the heating time may be 30min-35min.
  • the mass ratio of the rare earth nitrate to water may be (3-4):1.
  • the template polymer is selected from, for example, PVA powder; specifically, the PVA powder can be 1788 type.
  • the mass fraction of the high molecular polymer solution may be 10%-12%.
  • the water in step S3-1, may be ultrapure water.
  • step S3-1 the prepared polymer solution can be stirred for 6h-8h to completely dissolve the PVA powder in water.
  • step S3-1 the pH value of the silica sol is 8.5-9.0, the concentration is 2-4mol/L, the mass fraction is 15-25%, and the density is 0.957g/cm 3 .
  • the mass ratio of the high molecular polymer solution to the silica sol can be, for example, 1:1, 1:2, 1:3, 1:4, 1: 5 or 1:6.
  • step S3-2 the SiO 2 precursor spinnable sol is obtained by stirring after mixing; specifically, the stirring time may be 0.5h-3h.
  • the inner diameter of the electrospinning needle is 0.50 mm to 0.60 mm; specifically, the parameters of the electrospinning can be: relative humidity 25% to 45 %, the extrusion speed is 0.9 ⁇ 1.5ml/h, the voltage is 12 ⁇ 16kv, the distance between the receiving device and the spinneret is 8 ⁇ 10cm, the spinning time is 1h ⁇ 4h, the metal drum is used as the receiving device, and the drum speed 40 ⁇ 70r/min.
  • step S3-3 place in an oven to remove static electricity, specifically, place in an oven at 40-50° C. for 30 minutes to 1 hour to remove static electricity.
  • the calcination procedure may be: heating from room temperature to 800°C at a heating rate of 5°C/min, and holding at 800°C for 1 hour.
  • step S3-3 it can be calcined at 900-1300°C, and the calcining program is controlled as follows: from room temperature to 900-1300°C, the heating rate is 5°C/min, and The highest temperature is kept for 1h.
  • the hydrophobic modifier is prepared by the following method: the silane coupling agent and ethanol are mixed according to the mass ratio of 3: (8-12), and 0.5-2wt% Dilute nitric acid to adjust the pH value of the mixed solution to about 3, stir for 1h to 2h to hydrolyze to obtain a hydrophobic modifier;
  • the silane coupling agent can be KH-570, KH-550, KH-560, chlorine Trimethylsilane, Tridecafluorooctyltriethoxysilane, Heptadecafluorodecyltriethoxysilane, Tridecafluorooctyltrimethoxysilane, Heptadecafluorodecyltrimethoxysilane, Acetoxy Trimethylsilane, benzyldimethylchlorosilane, benzyltrichlorosilane, benzyltriethoxysilane, tert-buty
  • step S4 the hydrophobic modification is carried out in a vacuum drying oven; specifically, the temperature of the drying oven may be 40-80°C, and the treatment time is 4h-8h.
  • step S4 the drying is performed in an oven; specifically, it is performed in an air atmosphere.
  • the purpose of drying is to remove residual solvent.
  • the drying temperature is 50-70°C, and the drying time is 6h-10h.
  • step S5 after adding the gel catalyst, reinforcing fibers and fiber dispersants may be added.
  • the fiber dispersant can be at least one of sodium lauryl sulfonate, polyethylene glycol, sodium lauryl sulfate, sodium hexametaphosphate and the like.
  • a gel catalyst is added to convert the rare earth silica sol into a rare earth doped gel.
  • the gel catalyst can be one or more of ammonia water, dimethylformamide, ammonia water ethanol dilution, etc. .
  • the drying method may be normal temperature and pressure drying, critical drying, supercritical drying, and the like.
  • At least one of CO 2 , methanol, and ethanol can be selected as the drying medium for the critical drying and supercritical drying.
  • the drying conditions at normal temperature and pressure may be to dry at 60, 80 and 120° C. for 2 hours respectively to obtain the final product.
  • the conditions for the carbon dioxide supercritical drying are: in the case of ethanol as the solvent, soak with liquid carbon dioxide for 3 days at 5°C and 5.5MPa, and release the replaced ethanol; then raise the temperature to 35°C and 10.5MPa And keep it for 3 hours, then slowly release the pressure to normal pressure at a rate of 0.5MPa/h to obtain the final product.
  • the condition of the ethanol supercritical drying is that after raising the temperature and pressure to the critical point according to a preset program, the fluid inside the reactor is released at a slow speed at a constant temperature until the internal and external pressures are balanced.
  • N2 can be used to pre-fill the reactor.
  • the pressure of pre-filling N2 is 1-4MPa. When the temperature rises above 240°C, the heating rate is 0.5-2°C/min. When the pressure exceeds 8MPa, turn on the cooling device, slowly release the pressure, and release After the pressure was reduced to normal pressure, N2 was introduced to purge the reactor, and after cooling to room temperature, the final product was obtained.
  • the present invention also provides the application of the thermal insulation material or thermal insulation composite material, which can be used for thermal insulation in a high temperature and humid environment.
  • the thermal insulation material due to the flexibility and low thermal conductivity of the thermal insulation material, it can be used for thermal insulation under conditions of limited space.
  • the present invention also provides a smoke prevention and exhaust air duct
  • the smoke prevention and exhaust air duct includes a metal pipe
  • the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer
  • the heat shielding layer includes a heat insulating layer
  • the heat insulating layer Including the above-mentioned thermal insulation material or the above-mentioned thermal insulation composite material, or, the thermal insulation layer includes a skeleton, a filler, an anti-shrinkage additive and a high-temperature-resistant additive.
  • the heat shielding layer further includes at least one of a heat conducting layer and a heat reflecting layer.
  • the filler includes silica aerogel, aluminum silicate aerogel, alumina aerogel, composite silica aerogel, rare earth doped silica aerogel at least one of .
  • the filler has a core-shell structure, wherein the shell is aluminum silicate and/or alumina aerogel, the core is silica aerogel, or the shell is silica aerogel and the core is aluminum silicate and/or alumina aerogels.
  • the airgel may be a silica/alumina composite aerogel in which silica is composited with alumina.
  • the skeleton is made of fiber material, which may be at least one of aluminum silicate fiber, alumina fiber, glass fiber, mullite fiber, and SiO 2 ceramic nanofiber.
  • the high temperature resistant additive may be aluminum silicate, quartz powder, silicon micropowder and the like.
  • the embodiment of the present invention adopts electrospinning technology
  • silica sol is the main raw material
  • polyvinyl alcohol is the spinning aid.
  • the specific preparation method of the thermal insulation material includes the following steps:
  • the SiO 2 precursor spinnable sol mix the polymer solution with the silica sol and stir evenly to obtain the precursor sol with electrospinning performance; the pH value of the silica sol is 8.5-9.0, the concentration is 3.19mol/L, the mass The fraction is 19.1%, and the density is 0.957 g/cm 3 .
  • the PVA aqueous solution and the silica sol are mixed according to a mass ratio of 1:(1-6), and stirred for 0.5-3 hours to obtain a precursor sol.
  • the prepared PVA/SiO 2 ceramic nanofiber membrane is placed in an oven at 40-50°C for 30min-1h to remove static electricity.
  • the prepared PVA/SiO 2 composite ceramic nanofiber membrane is placed in a box furnace and calcined to remove organic matter, and a flexible SiO 2 ceramic nanofiber membrane is obtained; the calcination procedure for removing organic matter is: from room temperature to 800 °C °C, the heating rate is 5 °C/min, and it is kept at 800 °C for 1 h.
  • the SiO2 ceramic nanofiber membrane was calcined at 900-1300 °C, and the calcination program was controlled as follows: from room temperature to 900-1300 °C, the heating rate was 5 °C/min, and the highest temperature was kept for 1 h.
  • silane coupling agent and ethanol according to a certain mass ratio, and drop dilute nitric acid to hydrolyze it to prepare a hydrophobic modifier;
  • the silane coupling agent for preparing a hydrophobic modifier is KH-570.
  • the silane coupling agent and ethanol were mixed according to the mass ratio of 3:10, the pH value of the mixed solution was adjusted to about 3 with 1 wt% dilute nitric acid, and stirred for 2 hours to hydrolyze to obtain a hydrophobic modifier.
  • step 6 Take out the wet SiO 2 ceramic nanofibers in step 6 and place them in an oven, and dry them in an air atmosphere to remove residual solvents.
  • the drying temperature is 50-70°C, and the drying time is 6-10 hours.
  • the present embodiment provides a kind of thermal insulation material, and its preparation method comprises the following steps:
  • step 4) Place the PVA/ SiO2 composite nanofiber membrane obtained in step 3) in an oven at 50°C for 30 minutes to remove static electricity and facilitate storage and subsequent operations;
  • the above-mentioned PVA/SiO 2 composite nanofiber film is peeled off from the tin foil, and placed in a box furnace to be calcined in an air atmosphere so as to remove organic components to obtain SiO 2 ceramic nanofibers with flexibility.
  • the parameters of the calcination process are : From room temperature to 800°C, the heating rate is 5°C/min, and the temperature is kept at 800°C for 1 hour;
  • silane coupling agent KH-570
  • 20g of ethanol stir to mix and add 1wt% dilute nitric acid dropwise, adjust the pH of the mixed solution to 3, and stir for 2h to make the silane coupling
  • the coupling agent is fully hydrolyzed to obtain a hydrophobic modifier
  • step 7) Soak the SiO2 ceramic nanofiber membrane in step 5) in the hydrophobic modifier prepared in step 6), and place it in a vacuum oven at 60°C for 4 hours;
  • step 8) Take the SiO2 ceramic nanofiber membrane in step 7) out of the hydrophobic modifier, and place it in a 60°C oven to dry for 8 hours to remove the solvent to obtain a SiO2 ceramic nanofiber membrane with hydrophobic properties, that is, the insulation barrier of the present invention. hot material;
  • the interior of the SiO 2 ceramic nanofiber membrane prepared above is a three-dimensional interpenetrating network structure composed of ceramic fibers, the average diameter of the ceramic fibers is 313nm, and the thermal conductivity is 0.053W/mK.
  • FIG. 2 is a SEM image of the SiO2 ceramic nanofiber membrane prepared in Example 1.
  • Fig. 3 is the TG curve of the SiO 2 ceramic nanofiber membrane prepared in Example 1.
  • Figure 4 is the hydrophobically modified SiO2 ceramic nanofiber membrane prepared in Example 1.
  • the thermal insulation material was prepared by the same method as in Example 1, wherein the amount of PVA was specifically shown in Table 1.
  • Table 1 also gives the density, fiber average diameter and thermal conductivity of SiO2 ceramic nanofiber membranes with different PVA content.
  • Table 1 preferably, in the case of 10wt% PVA solution and silica sol at a ratio of 1:2, the SiO 2 ceramic nanofiber membrane has the lowest thermal conductivity and the best thermal insulation performance; the higher the proportion of silica sol, the SiO 2 The higher the density of the ceramic nanofiber membrane.
  • Table 2 shows the tensile strength of thermal insulation materials prepared with different PVA content. It can be seen from Table 2 that in the case of 10wt% PVA solution and silica sol at a ratio of 1:2, the thermal insulation material has the best tensile strength. Compared with other ratios, thermal insulation materials have the best tensile properties.
  • Table 3 shows the tensile strength of thermal insulation materials after different heat treatments. It can be seen from Table 3 that the mass ratio of 10wt% PVA solution to silica sol is 1:2, and the tensile strength is different after different heat treatments. Under heat treatment conditions, the thermal insulation material has the highest tensile strength and the best tensile performance of the material.
  • This implementation provides a thermal insulation material, the preparation method of which is different from Example 1 in that 7g of 10wt% PVA aqueous solution and 7g of silica sol (the mass ratio of 10wt% PVA to silica sol is 1:1) are used in step 2). ) uniformly mixed to form an electrospinning precursor sol.
  • the prepared SiO 2 ceramic nanofiber membrane has an average diameter of 263nm and a thermal conductivity of 0.063W/mK.
  • This implementation provides a thermal insulation material, the preparation method of which is different from Example 1 in that step 2) uses 5g of 10wt% PVA aqueous solution and 10g of silica sol (the mass ratio of 10wt% PVA to silica sol is 1:2 ) uniformly mixed to form an electrospinning precursor sol.
  • the prepared SiO 2 ceramic nanofiber membrane has an average diameter of 283nm and a thermal conductivity of 0.053W/mK.
  • This implementation provides a thermal insulation material, the preparation method of which is different from Example 1 in that 2g of 10wt% PVA aqueous solution and 10g of silica sol (the mass ratio of 10wt% PVA to silica sol is 2:5) are used in step 2). ) uniformly mixed to form an electrospinning precursor sol.
  • the prepared SiO2 ceramic nanofiber membrane has an average diameter of 350nm.
  • This implementation provides a thermal insulation material.
  • the preparation method is different from Example 1 in that step 3) is replaced by: put the above spinning solution into a 10ml syringe, use a spinneret with an inner diameter of 0.60mm, and electrospin
  • the control humidity is 25% when spinning, the working voltage of the equipment is 16kV, the injection rate is 1.5ml/h, the tin foil roller is used as the receiving device, the speed is 60r/min, and the distance between the spinning needle and the tin foil is 8cm, and electrospinning is carried out
  • the average diameter of the PVA/SiO 2 composite nanofiber membrane is 315nm
  • the average fiber diameter of the SiO 2 ceramic nanofiber membrane after removing organic matters is 298nm
  • the thermal conductivity is 0.054W/mK.
  • This implementation provides a thermal insulation material.
  • the difference between its preparation method and Example 1 is that the calcination temperature in step 5) is 900°C, and the control parameters of the calcination process are: from room temperature to 900°C, and the heating rate is 5°C /min, and held at a final temperature of 900°C for 2h.
  • the fiber interpenetrating network of the SiO 2 ceramic nanofiber membrane calcined at 900°C to remove organic matter was higher than that of Example 1, from 2.037MPa to 4.145MPa.
  • This implementation provides a thermal insulation material, the preparation method of which is different from Example 1 in that in step 7), the SiO2 ceramic nanofiber membrane in step 5) is soaked in the hydrophobic modifier prepared in step 6), and placed in Modification treatment in a vacuum oven at 60°C for 8 hours. Then place it in an oven at 60°C and dry it in air atmosphere for 10h to obtain a SiO2 ceramic nanofiber membrane with good hydrophobic properties.
  • This implementation provides a thermal insulation material, the preparation method of which is different from that of Example 1 in that in step 3), the PVA/ SiO2 composite nanofiber membrane prepared by electrospinning is stacked in multiple layers, and laminated after stacking Or hot pressing to prepare a felt-like material.
  • This embodiment provides a thermal insulation material, the preparation method of which comprises the following steps:
  • step 4) Place the PVA/SiO2 composite nanofiber membrane obtained in step 3) in an oven at 50° C. for 30 minutes to remove static electricity and facilitate storage and subsequent operations;
  • the above-mentioned PVA/SiO2 composite nanofiber film is peeled off from the tin foil, and placed in a box furnace to be calcined in an air atmosphere so as to remove organic components to obtain SiO2 ceramic nanofibers with flexibility.
  • the parameters of the calcining process are: from The temperature is raised from room temperature to 800°C, the heating rate is 5°C/min, and the temperature is kept at 800°C for 1 hour;
  • silane coupling agent KH-570
  • 20g of ethanol stir to mix and add 1wt% dilute nitric acid dropwise, adjust the pH of the mixed solution to 3, and then stir for 2h to make the silane coupling
  • the coupling agent is fully hydrolyzed to obtain a hydrophobic modifier
  • step 7) Soak the SiO2 ceramic nanofiber membrane in step 5) in the hydrophobic modifier prepared in step 6), and place it in an oven at 60° C. for 4 hours;
  • step 8) Take out the SiO2 ceramic nanofiber membrane in step 7) from the hydrophobic modifier, and place it in a 60° C. oven to dry for 8 hours to remove the solvent to obtain a SiO2 ceramic nanofiber membrane with hydrophobic properties;
  • the SiO prepared above The interior of the ceramic nanofiber membrane is a three-dimensional interpenetrating network structure composed of ceramic fibers, and the average diameter of the ceramic fibers is 338nm.
  • This implementation provides a thermal insulation material, the preparation method of which is different from that of Example 10 in that the calcination temperature in step 5) is selected as 900°C, and the control parameters of the calcination process are: from room temperature to 900°C, with a heating rate of 5 °C/min with a final temperature of 900 °C for two hours.
  • the fiber interpenetrating network of the SiO2 ceramic nanofiber membrane calcined at 900° C. to remove organic matter was higher than that in Example 1, from 2.037 MPa to 4.145 MPa.
  • This embodiment provides a thermal insulation composite material, the preparation method of which comprises the following steps:
  • Silica sol preparation Silica sol is prepared by mixing silicon source, water, alcohol solvent, and silicon micropowder, adding a hydrolysis catalyst to the silica sol to accelerate the hydrolysis of the silicon source, and obtain silica sol faster.
  • the silicon source can be sodium silicate, ethyl orthosilicate, methyl orthosilicate, tetrapropoxysilane, tetrabutoxysilane, dimethyldimethoxysilane or dimethyldiethoxysilane or its combination.
  • the particle size range of silica powder is 600 mesh-1500 mesh.
  • the hydrolysis catalyst can be selected from hydrochloric acid, oxalic acid, nitric acid, sulfuric acid, phosphoric acid or a combination thereof.
  • the alcohol solvent can be methanol, ethanol or a combination thereof.
  • An opacifying agent can also be added to the silica sol to enhance the temperature insulation performance at high temperature, and the opacifying agent includes titanium dioxide, carbon black, SiC, potassium hexatitanate, ZrO2 , etc. Further, titanium dioxide may be anatase titanium dioxide. Further, the titanium dioxide can be fluorine-doped or nitrogen-doped titanium dioxide nanoparticles to enhance the shading effect of infrared radiation.
  • rare earth silica sol preparing a rare earth compound into a rare earth solution, and mixing the rare earth solution with the silica sol to obtain the rare earth silica sol.
  • the rare earth compound can be yttrium metal salt, scandium metal salt, neodymium metal salt, ytterbium metal salt; yttrium metal oxide, scandium metal oxide, neodymium metal oxide, ytterbium metal oxide.
  • yttrium metal salt can be yttrium nitrate, yttrium chloride, yttrium oxalate, yttrium carbonate; scandium metal salt can be scandium nitrate, scandium chloride, scandium oxalate, scandium carbonate; neodymium metal salt can be neodymium nitrate, neodymium chloride , yttrium oxalate, neodymium carbonate; ytterbium metal salt can be ytterbium nitrate, ytterbium chloride, ytterbium oxalate, ytterbium carbonate.
  • the rare earth solution may contain one or one of the above rare earth compounds.
  • SiO2 ceramic nanofiber membrane is soaked in the hydrophobic modifier, and hydrophobic modifier contains silane coupling agent and ethanol, and SiO2 ceramic nanofiber membrane is vacuum-dried after soaking.
  • Gel preparation add a gel catalyst to the rare earth silica sol, pour it into the modified fiber preform, and then let it stand for 24-72 hours to obtain a gel.
  • the reinforcing fiber and the fiber dispersant can also be added after adding the gel catalyst.
  • the fiber dispersant can be sodium lauryl sulfonate, polyethylene glycol, sodium lauryl sulfate, sodium hexametaphosphate, etc.
  • the rare earth silica sol is transformed into a rare earth doped gel by adding a gel catalyst, and the gel catalyst is ammonia water, dimethylformamide, ammonia water ethanol dilution and the like.
  • the drying method may be normal temperature and normal pressure drying, critical drying, supercritical drying and the like.
  • the drying medium of critical drying and supercritical drying can be CO2, methanol or ethanol.
  • the obtained rare earth-doped airgel-ceramic nanofiber composite material can be used as a thermal insulation layer.
  • the conditions for drying at normal temperature and pressure are to dry at 60, 80 and 120° C. for 2 hours respectively, and finally obtain white SiO 2 airgel powder.
  • the condition of carbon dioxide supercritical drying is that in the case of ethanol as the solvent, soak with liquid carbon dioxide at 5°C and 5.5MPa for 3 days, and release the replaced ethanol; then raise the temperature to 35°C and 10.5MPa and keep it for 3h, then Slowly release the pressure to normal pressure at a rate of 0.5 MPa/h to obtain the final product.
  • the condition of ethanol supercritical drying is that after raising the temperature and pressure to the critical point according to the preset program, the fluid inside the reactor is released at a slow speed at a constant temperature until the internal and external pressures are balanced.
  • N2 can be used to pre-fill the reactor.
  • the pressure of pre-filling N2 is 1-4MPa. When the temperature rises above 240°C, the heating rate is 0.5-2°C/min. When the pressure exceeds 8MPa, turn on the cooling device and release the pressure slowly. , after releasing the pressure to normal pressure, N 2 was introduced to purge the reactor, and after cooling to room temperature, the final product was obtained.
  • the present invention also provides a smoke prevention and exhaust air duct
  • the smoke prevention and exhaust air duct includes a metal pipe
  • the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer
  • the heat shielding layer includes a heat insulating layer
  • the heat insulating layer Including the above-mentioned thermal insulation material or the above-mentioned thermal insulation composite material, or, the thermal insulation layer includes a skeleton, a filler, an anti-shrinkage additive and a high-temperature-resistant additive.
  • the heat shielding layer further includes at least one of a heat conducting layer and a heat reflecting layer.
  • the filler includes silica aerogel, aluminum silicate aerogel, alumina aerogel, composite silica aerogel, rare earth doped silica aerogel at least one of .
  • the filler has a core-shell structure, wherein the shell is aluminum silicate and/or alumina aerogel, the core is silica aerogel, or the shell is silica aerogel and the core is aluminum silicate and/or alumina aerogels.
  • the airgel may be a silica/alumina composite aerogel in which silica and alumina are composited.
  • the skeleton is made of fiber material, which may be at least one of aluminum silicate fiber, alumina fiber, glass fiber, mullite fiber, and SiO 2 ceramic nanofiber.
  • the high temperature resistant additive may be aluminum silicate, quartz powder, silicon micropowder and the like.
  • each air duct unit has a quick connection function, specifically, the anti-smoke air duct is quickly spliced by a front air duct unit and a rear air duct unit.
  • the main structure of each air duct unit includes a metal main frame, an inner wall heat shielding layer attached to the inner wall of the frame, an outer wall heat shielding layer attached to the outer wall of the frame, and a fire-resistant sealant attached to the outside of the outer wall heat shielding layer.
  • the heat shielding layer of the inner wall, the metal main body frame, the heat shielding layer of the outer wall, and the outer refractory sealant are sequentially covered and connected, and the connection method can be physical or chemical connection methods such as rivet fixing and adhesion.
  • the heat shielding layer of the inner wall and the heat shielding layer of the outer wall can be composed of a single layer or multiple layers of a heat insulating layer, a heat conducting layer and a heat reflecting layer.
  • each end of each air duct unit is provided with an extension layer and a receiving area.
  • the smoke prevention air duct includes a front air duct, a rear air duct, a mounting seat, a positioning rod and a positioning cylinder; one end of the front air duct is detachably connected to the rear air duct; the mounting base is symmetrically arranged On the sides of the front air duct and the rear air duct, the positioning rod and the positioning cylinder are correspondingly arranged on the opposite sides of the mounting seats on both sides, and the positioning rod and the positioning cylinder are slidingly fitted;
  • the inner wall and/or outer wall of the front air duct is provided with a heat shielding layer, and the inner wall and/or outer wall of the rear air duct is provided with a heat shielding layer; the heat shielding layer includes at least one of a heat insulating layer, a heat conducting layer, and a heat reflecting layer ;
  • the heat insulation layer is attached to the inner wall and/or outer wall of the front air duct and the rear air duct.
  • the smoke prevention air duct includes a front air duct and a rear air duct; one end of the front air duct is detachably connected to the rear air duct; both ends of the front air duct and the rear air duct are respectively provided with angle steel Flange; the inner wall and/or outer wall of the front air duct is provided with a heat shielding layer, and the inner wall and/or outer wall of the rear air duct is provided with a heat shielding layer; the heat shielding layer includes a heat insulating layer, a heat conducting layer and a heat reflecting layer At least one of them; the heat insulation layer is attached to the inner wall and/or outer wall of the front air duct and the rear air duct.
  • the above connection assembly includes: a surrounding fixing hoop 120 made of metal or other high temperature resistant materials, bolts 121 and nuts 122, as shown in FIG. 7 .
  • the encircling fixing collar 120 also includes a limit hole, and the width of the encircling fixing collar 120 is not less than the length of the outer wall heat shielding layer 200 extending from the air duct.
  • the fixing method after the two air duct units are connected can be as follows: the surrounding fixing hoop 120 covers the gap between the metal pipe 100 of the two air duct units and the heat shielding layer 200, the bolts 121 pass through the corresponding limiting holes, and the nuts 122 Tighten securely.
  • the above technical solution provides a smoke prevention and exhaust air duct structure that can be quickly connected and fixed and has a heat insulation function.
  • the fast connection between the smoke prevention and exhaust air ducts is realized, the work efficiency is improved, and the smoke prevention and exhaust airtightness of the air ducts and the fire resistance performance will not be reduced at the same time, and the practicability is strong.
  • the technical scheme can realize quick connection between two air ducts, improves work efficiency, and at the same time ensures that the air duct's anti-smoke airtightness and fire resistance performance will not be reduced, and has strong practicability.
  • the present invention provides a technical solution, the inventors made the silica airgel part in the composite silica/aluminosilicate airgel particles or silica/alumina airgel particles Further modification and optimization, although silica airgel and aluminum-containing airgel are composited, the silica airgel itself may shrink and collapse under high temperature conditions. Adding anti-shrinkage additives (such as silicon micropowder) to silica airgel can inhibit and reduce the shrinkage and collapse of silica airgel through the crystal form change and volume change of silica micropowder at high temperature, and further improve the composite silica. /The temperature resistance of aluminum silicate airgel particles or composite silica/alumina airgel particles can further improve the temperature resistance of composite airgel, enhance the performance of heat insulation layer and improve the high temperature of anti-smoke and fire-resistant ventilation pipes Performance.
  • anti-shrinkage additives such as silicon micropowder
  • the application of enhanced airgel materials in the smoke exhaust duct can achieve better Low heat transfer coefficient and high temperature, so that the airgel material can be used in the field of anti-smoke and exhaust ducts, enhance the heat resistance of the anti-smoke and exhaust ducts, and make the anti-smoke and exhaust ducts work normally when a fire occurs effect.
  • the application of airgel heat insulation material in the smoke prevention and exhaust duct can also reduce the space occupied by the heat insulation material.
  • This technical solution can also solve the problem that the heat insulation material used in the smoke prevention and exhaust duct in the prior art will absorb water, cause the heat insulation structure to collapse, have a short life, and at the same time occupy a large space due to the high thermal conductivity.
  • the structure of the air duct will change and collapse, and the air duct will have defects, resulting in changes in the wind pressure inside the duct, air leakage, and a decrease in the exhaust performance of the air duct.
  • the volume of airgel will shrink in volume at high temperature (above 800 degrees Celsius), which will lead to structural changes and reduce thermal insulation performance.
  • the technical problem to be solved in the embodiment of the present invention is that the thermal insulation layer material will shrink and collapse the internal silica microstructure at high temperature. Problems with materials shrinking and collapsing at high temperatures.
  • the inventors improved and optimized the filler in the thermal insulation layer, synthesized and used a silica/alumina composite aerogel composed of silica and alumina, and the silica in the composite aerogel
  • the silicon portion provides excellent thermal insulation
  • the alumina portion provides excellent temperature resistance.
  • the combination of alumina and silica molecules can inhibit and reduce the shrinkage, melting and crystal form change of silica molecules at high temperature on the microscopic level, and reduce the powder shedding of the thermal insulation layer (airgel felt) on the macroscopic level, making
  • the filler still has thermal insulation performance under high temperature conditions, and maintains relatively good physical and chemical properties to meet the use requirements.
  • the inventor improved the internal structure of the silica airgel material by modifying and optimizing the silica airgel, and made the aluminum oxide/aluminum oxide with better fire resistance but slightly worse heat insulation performance Salt materials are combined with silica airgel to form composite silica airgel particles with an outer shell of aluminum oxide/aluminum salt and a core of silica airgel, or to form a shell of silica airgel with a
  • the inner core is a composite silica airgel particle of aluminum oxide/aluminum salt.
  • the silica airgel can be kept stable at high temperature, and at the same time, the composite particles have good heat insulation performance, and can also maintain good physical and chemical properties. Applying it to the heat insulation layer can meet the requirements of smoke prevention and ventilation. Pipeline usage requirements.
  • the inventors doped the silica airgel with rare earths.
  • the rare earth doping can increase the use temperature of the silica airgel, the application of the airgel under high temperature and extreme conditions can be expanded. It can control the density and microstructure of the aerogel, and further control the anion content in it, thereby controlling the thermal conductivity of the aerogel and its performance at high temperatures.
  • Rare earth elements that can be doped include yttrium, scandium, neodymium and ytterbium.
  • This technical solution can also solve the problem that the heat insulation material used in the smoke prevention and exhaust duct in the prior art will absorb water, cause the heat insulation structure to collapse, have a short life, and at the same time occupy a large space due to the high thermal conductivity.
  • the structure of the air duct will change and collapse, and the air duct will have defects, resulting in changes in the wind pressure inside the duct, air leakage, and a decrease in the exhaust performance of the air duct.
  • the present invention also provides a smoke-exhaust and fire-resistant ventilation duct.
  • the smoke-exhaust and fire-resistant ventilation duct includes a metal pipe, the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer, and the heat shielding layer includes a high-temperature expansion layer and a heat-insulating layer. It includes at least one of a heat conduction layer and a heat reflection layer, and the heat insulation layer adopts the above-mentioned thermal insulation material or thermal insulation composite material.
  • the high-temperature expansion layer includes a high-temperature foaming agent, multifunctional carbon particles, and a stabilizer.
  • the foaming temperature of the high-temperature foaming agent is greater than 500°C, and the high-temperature foaming agent is silicon carbide powder or granules.
  • the multifunctional carbon particles can be graphite, graphene.
  • the stabilizer is manganese dioxide.
  • the thickness of the high-temperature expansion layer is 1-5mm, and the thickness after expansion is 20-100mm.
  • a preferred solution is to further include airgel particles to improve the thermal insulation performance of the high-temperature expansion layer. The mass proportion of airgel particles added is 3-5%.
  • the high-temperature expansion layer may also contain a water reducer, which is sodium tripolyphosphate or sodium hexametaphosphate.
  • the high-temperature expansion layer expands and foams, and the multifunctional carbon particles in it are not tightly connected due to being dispersed. Thermal conductivity disappears, the high-temperature expansion layer changes from a heat-conducting function to a functional layer with high-temperature heat-insulating properties. At the same time, under this condition, these multifunctional carbon particles can absorb infrared rays and act as a sunscreen, further improving the heat insulation performance under high temperature conditions.
  • a smoke prevention and exhaust air duct with a fast connection and fixing structure, and the air duct is formed by splicing air duct units.
  • each air duct unit is shown in Figure 7 and Figure 8, including the metal main frame, the inner wall heat shielding layer attached to the inner wall of the frame, the outer wall heat shielding layer attached to the outer wall of the frame, and the outer wall heat shielding layer. Fire-resistant sealant attached to the outside of the layer.
  • the heat shielding layer of the inner wall, the metal main body frame, the heat shielding layer of the outer wall, and the outer refractory sealant are sequentially covered and connected, and the connection method can be common physical or chemical connection methods such as rivet fixing and adhesion.
  • the heat shielding layer of the inner wall and the heat shielding layer of the outer wall can be composed of a single layer or multiple layers of heat insulating layer, heat conducting layer and reflective layer.
  • each end of each air duct unit is provided with an extension layer and a receiving area.
  • the metal main frame is a color steel plate.
  • the surface of the metal body frame is coated with an antibacterial coating.
  • the extension layer refers to the structural layer extending outward from the main structure along the direction parallel to the pipe wall at one end of an air duct unit.
  • the receiving area refers to the other end of the extension layer on the air duct unit, which is reserved for connecting with the extension layer of another air duct unit.
  • the structure of the air duct unit can be extended in a single layer or multi-layer according to the structure of the extension layer, so that it can be attached to the extension layer when the air duct unit is connected.
  • the part of the structure that is extended at the receiving end is defined as the extended receiving layer.
  • the two air duct units there are two air duct units to be connected, and the two air ducts have the same structure, both of which include the main body of the air duct unit, the extension layer and the receiving area, excluding the extension receiving layer.
  • the main body of the air duct unit is composed of a metal pipe, a heat shielding layer on the inner wall of the metal pipe, and a heat shielding layer on the outer wall of the metal pipe.
  • the extension length in the direction is the same as the reserved width of the receiving area along the direction parallel to the pipe wall.
  • connection method is: one end of an air duct unit with an extension layer is connected to the end of another air duct unit with a receiving area, and the metal pipes of the two air duct units are in contact, and the extended outer wall heat shield is in contact.
  • One air duct unit has an outer wall heat shield extending from one end of the extension layer, and covers the metal pipe at the other end of the air duct unit having a receiving area. After connecting, the two air duct units fit tightly and are fixed by the connecting components.
  • the above-mentioned connection assembly includes: a surrounding fixing hoop made of metal or other high-temperature-resistant materials, bolts, and nuts.
  • the wrap-around fixing hoop also includes limit holes, and the width of the wrap-around fixing hoop is not less than the length of the heat shielding layer of the outer wall extending from the air duct.
  • the fixing method after the two air duct units are connected can be as follows: the surrounding fixing hoop covers the gap between the metal pipes of the two air duct units and the heat shielding layer, the bolts pass through the corresponding limiting holes, and are tightened with nuts.
  • the air duct can be rectangular, the length of the long side of the air duct is b ⁇ 500mm, the distance between the supports and hangers is d ⁇ 2800mm; Side length b ⁇ 2000mm, support and hanger spacing d ⁇ 1400.
  • the size of the rectangular duct can be 120mm, 160mm, 200mm, 250mm, 320mm, 400mm, 500mm, 630mm, 800mm, 1000mm, 1250mm, 1600mm, 2000mm, 2500mm, 3000mm, 3500mm, 4000mm.
  • the two air duct units to be connected are respectively provided with angle steel flange structures for connection at both ends, and the flanges are made of metal or other high temperature resistant materials.
  • the two angle steel flange structures on both sides of the connection joint of the pipe unit can be closely fitted and fixed by the connection component.
  • connection assembly includes: a plurality of bolts and nuts made of metal or other high temperature resistant materials.
  • the connection method is that the nut passes through the limit hole on the corresponding angle steel flange, and is fixed and locked by bolts.
  • a smoke prevention air duct in a technical solution involved in the present invention, includes a metal pipe 100, the inner wall and/or outer wall of the metal pipe 100 is provided with a heat shielding layer 200, and the heat shielding layer 200 includes At least one of the heat insulating layer 210 , the heat conducting layer 220 , and the heat reflecting layer 230 .
  • the thermal insulation layer can use the thermal insulation material mentioned above or the thermal thermal insulation composite material mentioned above.
  • the heat conduction layer 220 can be a metal heat conduction plate, such as high heat conduction metal materials such as copper and aluminum; it can also be a heat conduction metal structure, such as a hollow heat conduction interlayer; it can also be the heat conduction layer 220 of a device provided with a heat pipe.
  • the heat conducting layer 220 , the heat reflecting layer 230 , and the heat insulating layer 210 are sequentially stacked to form the heat shielding layer 200 .
  • Another arrangement is that the heat reflection layer 230 , the heat conduction layer 220 , and the heat insulation layer 210 are stacked in sequence to form the heat shielding layer 200 .
  • the heat insulating layer 210 is attached to the inner wall and/or the outer wall of the metal pipe 100 .
  • a smoke prevention air duct includes a front air duct 140 and a rear air duct 150, and one end of the front air duct 140 is detachably connected to the rear air duct 150.
  • the smoke prevention and exhaust air duct also includes a mounting base 160, a positioning rod 161 and a positioning cylinder 162.
  • the mounting base 160 is symmetrically arranged on the sides of the front air duct 140 and the rear air duct 150, and the positioning rod 161 and the positioning cylinder 162 correspond to They are arranged on opposite sides of the mounting bases 160 on both sides, and the positioning rod 161 and the positioning cylinder 162 are slidably matched, as shown in FIG. 8 .
  • first connection assembly and a second connection assembly are provided between the front air pipe and the rear air pipe;
  • the first connection assembly includes a limit hole, a guide hole, a limit rod and a nut, and the limit hole runs through the vertical
  • a smoke prevention air duct in one technical solution involved in the present invention, includes a metal pipe, the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer, and the heat shielding layer includes a heat insulating layer, a heat conducting At least one of layer, heat reflective layer.
  • the thermal insulation layer can use the thermal insulation material mentioned above or the thermal thermal insulation composite material mentioned above.
  • the heat conduction layer can be a metal heat conduction plate, such as copper, aluminum and other metal materials with high heat conduction performance; it can also be a heat conduction metal structure, such as a hollow heat conduction interlayer; it can also be a heat conduction layer of a device provided with a heat pipe.
  • a metal heat conduction plate such as copper, aluminum and other metal materials with high heat conduction performance
  • it can also be a heat conduction metal structure, such as a hollow heat conduction interlayer
  • it can also be a heat conduction layer of a device provided with a heat pipe.
  • the heat conducting layer, the heat reflecting layer and the heat insulating layer are stacked in sequence to form the heat shielding layer.
  • Another arrangement is that the heat reflection layer, the heat conduction layer, and the heat insulation layer are stacked in sequence to form a heat shielding layer.
  • the thermal insulation layer is attached to the inner wall and/or outer wall of the metal pipe.
  • the form of the heat conduction layer includes silica gel heat dissipation film, graphite heat dissipation film, metal heat conduction plate, heat pipe heat conduction plate.
  • the material of the metal heat conducting plate can be a copper plate or an aluminum plate.
  • the form of the heat conduction layer can also be a channel with a heat conduction structure, such as a double-layer hollow metal heat conduction plate.
  • the range of thermal conductivity of the heat conducting layer at 800°C is 20W/m ⁇ K-50W/m ⁇ K.
  • a heat conduction layer on the smoke exhaust duct can enhance the heat conduction and heat dissipation performance of the smoke exhaust duct, prevent local high temperature, and prevent the internal silica airgel particles from melting at high temperatures such as 600 ° C, so that the heat insulation layer can be used at high temperatures It can still maintain the structure stability under the circumstances, and meet the use requirements of the smoke prevention and exhaust duct.
  • the inventor also believes that the local high temperature can be reduced by setting a heat absorbing layer inside the smoke prevention and exhaust duct, so that the smoke prevention and exhaust duct can withstand higher temperatures.
  • a smoke prevention air duct in one technical solution involved in the present invention, includes a metal pipe, the inner wall and/or outer wall of the metal pipe is provided with a heat shielding layer, the heat shielding layer includes a heat insulating layer, and the heat insulating
  • the layer can use the above heat insulation material or the above heat insulation composite material, and the heat shielding layer can also include at least one of a heat conducting layer, a heat reflecting layer, and a heat absorbing layer.
  • a preferred method is that the heat conducting layer, the heat reflecting layer, the heat absorbing layer and the heat insulating layer are stacked in sequence to form the heat shielding layer.
  • the heat conducting layer, the heat reflecting layer, the heat absorbing layer and the heat insulating layer are stacked in sequence to form a heat shielding layer.
  • Another arrangement is that the heat reflective layer, the heat absorbing layer, and the heat insulating layer are stacked in sequence to form a heat shielding layer.
  • the thermal insulation layer is attached to the inner wall and/or outer wall of the metal pipe.
  • the heat absorbing layer is composed of heat storage materials.
  • the heat storage materials can be phase change materials, heated volatile materials, etc., and can also be preset cooling materials such as preset water tanks, preset carbon dioxide tanks, etc., which can be released when encountering high temperatures.
  • the loaded water, carbon dioxide and other cooling carriers absorb heat.
  • the phase change material can absorb heat and keep the temperature constant, so that in the case of local high temperature, the absorbed heat produces a phase change without increasing the temperature, thereby protecting the airgel structure of the heat insulation layer from collapsing, so that the heat insulation layer maintains the heat insulation effect , so that the entire heat shielding layer can still maintain the temperature insulation effect at high temperatures.
  • Phase change materials are molten salts, and molten salts include carbonates, chloride salts, and fluoride salts.
  • Installing a heat absorbing layer in the smoke exhaust duct can reduce the temperature of the smoke exhaust duct, prevent local high temperature, and prevent the internal silica airgel particles from melting at high temperatures such as above 600°C, so that the airgel heat insulation can reach the use Require.
  • the heat insulating layer, the heat conducting layer, the heat reflecting layer and the heat absorbing layer are fixed to each other by bonding and hot pressing.
  • the outside of the heat shielding layer can also be wrapped with glass fiber cloth and aluminum foil to prevent the filler from breaking and falling off.
  • the invention breaks through the characteristics of poor mechanical properties and brittleness of traditional ceramics, has good softness, and also retains the high temperature resistance characteristics of SiO2 materials.
  • the high molecular polymer solution is mixed with neutral silica sol to prepare spinnable sol; then, under certain humidity and temperature conditions, electrospinning is used to prepare organic/inorganic hybrid nanofiber membranes; In an air atmosphere, the calcination temperature was controlled to remove the organic components in the fiber membrane to obtain a SiO 2 ceramic nanofiber membrane; finally, the prepared SiO 2 ceramic nanofiber membrane was hydrophobically modified by using a silane coupling agent.
  • the present invention adopts the commercialized silica sol as raw material, has simple process, short preparation period, and good formability.
  • the SiO2 ceramic nanofiber membrane prepared by the present invention has a three-dimensional interpenetrating network structure composed of ceramic fibers and has low thermal conductivity.
  • the average fiber diameter is 200-350nm
  • the thickness of the ceramic fiber membrane is 0.102-0.1836mm
  • the tensile strength is 0.51-4.145Mpa
  • the thermal conductivity is 0.04141-0.07416W/mK.
  • the SiO2 ceramic nanofiber membrane of the present invention has good mechanical properties, light weight, and good hydrophobicity, and is expected to be applied in aerospace fields and high-temperature and humid environments to realize high-efficiency heat insulation.

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Abstract

一种保温隔热材料及其制备方法和应用，所述保温隔热材料为一种膜状材料或毡状材料，是一种柔性材料；所述保温隔热材料中包括SiO2陶瓷纳米纤维构成的三维的互穿网络结构，所述纤维的平均直径为200nm～350nm。本发明的制备方法的工艺简单、制备周期短、成型性好，有陶瓷纤维构成三维的互穿网络结构，具有低导热系数，力学性能良好、质量轻、疏水性能好，有望应用于航天航空领域以及高温潮湿环境，实现高效隔热。

Description

一种保温隔热材料及其制备方法和应用
本申请要求2021年9月17日向中国国家知识产权局提交的专利申请号为202111091769.5，发明名称为“一种柔性耐高温SiO 2陶瓷纳米纤维膜的制备方法”的在先申请的优先权。这篇在先申请的全文通过引用的方式结合于本申请中。
本申请要求2021年9月17日向中国国家知识产权局提交的专利申请号为202111091766.1，发明名称为“一种稀土掺杂二氧化硅气凝胶的制备方法”的在先申请的优先权。这篇在先申请的全文通过引用的方式结合于本申请中。
本申请要求2022年4月22日向中国国家知识产权局提交的PCT申请号为PCT/CN2022/088412，发明名称为“一种耐高温防排烟风管及其制造方法”的在先申请的优先权。这篇在先申请的全文通过引用的方式结合于本申请中。
本申请要求2022年4月22日向中国国家知识产权局提交的PCT申请号为PCT/CN2022/088414，发明名称为“一种耐高温防排烟风管”的在先申请的优先权。这篇在先申请的全文通过引用的方式结合于本申请中。
技术领域
本发明属于保温隔热材料领域，涉及一种保温隔热材料及其制备方法和应用。
背景技术
近年来，随着航天航空领域对飞行器速度的要求越来越快，对具有良好机械柔软性、轻质高效的隔热材料的研发引起各个行业广泛的关注，同时对隔热材料的高温机械稳定性、力学性能等都有更高的要求。无机材料、特别是陶瓷材料具有耐高温、耐腐蚀、绝缘性好等优点，在高超速飞行器上作为高温隔热材料有着一定的应用优势。二氧化硅SiO 2是一种在自然界中广泛分布的无毒、无味、无污染的无机非金属材料，具有耐温性好、耐腐蚀性优异、导热系数好、绝缘性好、化学性能稳定等特点，在众多领域均得到广泛应用。
但相对于金属与高分子材料，大部分陶瓷材料在外加载荷作用下，直接发生脆性断裂，这种无机材料所具有的脆性大、力学性能差、不易折弯等缺陷严重限制其在实际中的使用。为不使陶瓷材料的脆性影响材料的性能以及材料应用的深度和广度，如何改善陶瓷材料的脆 性乃至于研制出具有柔性的可弯曲不脆裂的陶瓷一直是陶瓷材料研究工作者的研究重点之一。
发明内容
本发明的目的是提供可解决航天航空领域现有陶瓷基隔热材料脆性大、不易安装维修、不适用于高工作温度等缺陷的一种保温隔热材料及其制备方法和应用。本发明的保温隔热材料，其中的纤维直径为纳米级，赋予材料柔性，而所述材料中独特的大孔隙率和较大比表面积，使得材料拥有更低的导热系数。同时，本发明还提供一种疏水改性的保温隔热材料，该材料具有应用于高温潮湿环境的前景。本发明还提供所述保温隔热材料的制备方法，所述方法具有工艺简单、原料易得、可以降低生产成本，具有批量化生产的前景。
具体地，本发明提供如下技术方案：
一种保温隔热材料，所述保温隔热材料为一种膜状材料或毡状材料，是一种柔性材料；所述保温隔热材料中包括SiO 2陶瓷纳米纤维构成的三维的互穿网络结构，所述纤维的平均直径为200nm～350nm。
根据本发明，所述保温隔热材料具备下述性能中的至少一种：
1)耐高温，可在800～1200℃下使用；
2)密度(g/cm)介于0.08至0.20之间；
3)导热系数为0.04～0.08W/mK；
4)拉伸力学强度为0.5～4.5MPa；
根据本发明，所述保温隔热材料中还包括遮光剂。
根据本发明，所述纤维为具有中空结构的纳米中空纤维。
本发明还提供一种所述保温隔热材料的制备方法，所述方法包括以下步骤：
1)配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
2)配制SiO 2前驱体可纺溶胶：将步骤1)中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；所述高分子聚合物溶液与硅溶胶的重量比为1:(1～6)；
3)制备保温隔热材料：将步骤2)的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到所述保温隔热材料。
根据本发明，所述方法还包括以下步骤：
4)制备具有疏水性能的保温隔热材料：采用疏水改性剂对步骤3)中的保温隔热材料进 行疏水改性处理，干燥，得到所述具有疏水性能的保温隔热材料。
本发明还提供一种保温隔热复合材料，所述复合材料是所述保温隔热材料与二氧化硅气凝胶或稀土掺杂二氧化硅气凝胶的复合物。
根据本发明，所述复合材料是上述保温隔热材料与二氧化硅气凝胶的复合物，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述二氧化硅气凝胶作为填料。
根据本发明，所述复合材料是上述保温隔热材料与稀土掺杂二氧化硅气凝胶的复合物，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述稀土掺杂二氧化硅气凝胶作为填料。
根据本发明，所述气凝胶中进一步包括硅微粉。
根据本发明，所述气凝胶中进一步包括遮光剂。
本发明还提供一种所述保温隔热复合材料的制备方法，所述方法包括以下步骤：
S1.制备硅溶胶：将硅源、水、醇溶剂混合制备硅溶胶；
S2.制备稀土硅溶胶：配置稀土化合物溶液，并将稀土化合物溶液与上述硅溶胶混合，得到稀土硅溶胶；
S3.制备纤维预制件，包括以下步骤：
S3-1.配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
S3-2.配制SiO 2前驱体可纺溶胶：将步骤S3-1中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；
S3-3.制备纤维预制件：将步骤S3-2的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到纤维预制件；
S4.纤维预制件改性：采用疏水改性剂对步骤S3中的纤维预制件进行疏水改性处理，干燥，得到具有疏水性能的纤维预制件；
S5.制备凝胶：向步骤S1的硅溶胶或步骤S2的稀土硅溶胶中加入凝胶催化剂后，将其浇筑至步骤S3的纤维预制件或步骤S4的具有疏水性能的改性纤维预制件中，静置，获得凝胶；
S6.干燥：对步骤S5的凝胶进行干燥，得到所述保温隔热复合材料。
本发明还提供所述保温隔热材料或所述保温隔热复合材料的应用，用于高温潮湿环境下的保温隔热。
本发明还提供一种防排烟风管，所述防排烟风管包括金属管道，金属管道的内壁和/或外壁设置有热屏蔽层，所述热屏蔽层包括绝热层，所述绝热层包括所述保温隔热材料或所述保 温隔热复合材料。
与现有技术相比，本发明具有以下显著优势：
1、本发明采用PVA为助剂，将聚合物溶剂与硅溶胶混合作为前驱体溶胶，通过溶胶-凝胶电纺法制备具有特殊孔隙率的保温隔热材料，该制备工艺简单、原料易得、可以降低生产成本，具有批量化生产的前景；
2、本发明制备的保温隔热材料具有厚度薄且可控的优点，以及良好的机械强度，可随意进行折叠弯曲，同时其也具有良好的拉伸强度(例如拉伸强度可以高达4.145MPa)；
3、本发明制备的保温隔热材料可在800～1200℃下应用且不改变其纤维形貌和结构，同时具有低的导热系数，可在高温领域作为耐高温隔热材料；
4、本发明制备的疏水改性的保温隔热材料具有疏水性能，结合其耐高温性能，在高温潮湿环境具有潜在的应用。
附图说明
为了更清楚地说明本发明实施例技术中的技术方案，下面将对实施例技术描述中所需要使用的附图作简单地介绍，附图仅是用来提供对本发明的进一步理解，且作为构成说明书的一部分，与下述的具体实施方式一起用于解释本发明，但并不构成对本发明的限制，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为SiO 2陶瓷纳米纤维膜的制备流程图。
图2为实施例1制备的SiO 2陶瓷纳米纤维膜的SEM图像。
图3为实施例1制备的SiO 2陶瓷纳米纤维膜的TG曲线。
图4为实施例1制备的疏水改性的SiO 2陶瓷纳米纤维膜。
图5为本发明的纳米中空纤维电镜图像。
图6为本发明的同轴套管针头示意图。
图7为本发明的防排烟风管示意图。
图8为本发明的快速拆装风管示意图。
图9为本发明的热屏蔽层示意图。
图10为本发明的绝热层包裹耐高温保护层示意图。
图11为本发明的高温膨胀层在不同温度下形态示意图。
图12为本发明的排烟风管结构示意图。
图中：100-金属管道；101-抗菌金属管道；110-角钢法兰；120-环绕式固定箍；121-螺栓；122-螺母；130-耐火密封胶；200-热屏蔽层；210-绝热层；220-导热层；230-热反射层；250-耐高温保护层；260-高温膨胀层；810-内层针头；820-外层针头；830-接收装置；880-纳米中空纤维。
具体实施方式
[保温隔热材料]
如前所述，本发明提供了一种保温隔热材料，其为一种膜状材料或毡状材料，是一种柔性材料；所述保温隔热材料中包括SiO 2陶瓷纳米纤维构成的三维的互穿网络结构，所述纤维的平均直径为200nm～350nm。
根据本发明的一种实施方式，所述纤维的平均直径例如为200nm、205nm、240nm、245nm、280nm、281nm、282nm、283nm、284nm、285nm、286nm、287nm、288nm、289nm、290nm、300nm、310nm、320nm、330nm、340nm或350nm。所述纤维的平均直径的标准偏差为30nm～70nm，例如为30nm、35nm、40nm、45nm、50nm、55nm、60nm、65nm或70nm。
根据本发明的一种实施方式，所述保温隔热材料表面具有疏水功能基团。
根据本发明的一种实施方式，当所述保温隔热材料为膜状材料时，其厚度为0.5mm～5.0mm，具体地可以为0.5mm、0.8mm、0.9mm、1.0mm、1.3mm、1.5mm、1.8mm、2.0mm、2.2mm、2.5mm、2.8mm、3.0mm、3.4mm、3.5mm、3.8mm、4.0mm、4.2mm、4.5mm或5.0mm；当所述保温隔热材料为毡状材料时，其厚度为0.5cm～5cm，具体地可以为0.5cm、1cm、1.5cm、2.0cm、2.5cm、3cm、3.5cm、4cm、4.5cm或5cm。
根据本发明的一种实施方式，所述保温隔热材料耐高温，具体可在800～1200℃下使用。
根据本发明的一种实施方式，所述保温隔热材料的密度(g/cm)介于0.08至0.20之间，例如为0.08、0.09、0.10、0.11、0.12、0.13、0.14、0.15、0.16、0.17、0.18、0.19或0.20。
根据本发明的一种实施方式，所述保温隔热材料具有低导热系数，具体地，其导热系数为0.04～0.08W/mK，示例性地，为0.04、0.041、0.04141、0.042、0.044、0.05、0.06、0.07、0.072、0.074、0.07416、0.076、0.078、0.08W/mK。
根据本发明的一种实施方式，所述保温隔热材料的拉伸力学强度为0.5～4.5MPa，具体的，可以为0.5、0.51、0.55、0.6、0.8、1.0、2.0、3.0、3.5、4.0、4.1、4.145、4.2、4.3、4.4或4.5MPa。
根据本发明的一种实施方式，所述保温隔热材料中还包括遮光剂，目的在于增强在高温情况下的隔温性能。具体地，所述遮光剂可以包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2等中的至少一种。进一步的，二氧化钛可以是锐钛矿型二氧化钛。进一步的，二氧化钛可以是氟掺杂或者氮掺杂的二氧化钛纳米颗粒。
根据本发明的一种实施方式，所述纤维为具有中空结构的纳米中空纤维。
[保温隔热材料的制备方法]
本发明还提供一种制备上述保温隔热材料的方法，所述方法包括以下步骤：
1)配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
2)配制SiO 2前驱体可纺溶胶：将步骤1)中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；所述高分子聚合物溶液与硅溶胶的重量比为1:(1～6)；
3)制备保温隔热材料：将步骤2)的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到所述保温隔热材料。
根据本发明的一种实施方案，所述方法还包括以下步骤：
4)制备具有疏水性能的保温隔热材料：采用疏水改性剂对步骤3)中的保温隔热材料进行疏水改性处理，干燥，得到所述具有疏水性能的保温隔热材料。
根据本发明的一种实施方式，在步骤1)中，所述模板聚合物例如选自PVA粉末；具体地，所述PVA粉末可采用1788型。
根据本发明的一种实施方式，在步骤1)中，所述高分子聚合物溶液的质量分数可为10％～12％。
根据本发明的一种实施方式，在步骤1)中，所述水可采用超纯水。
根据本发明的一种实施方式，在步骤1)中，所述配制高分子聚合物溶液可通过搅拌6h～8h使PVA粉末完全溶解于水中。
根据本发明的一种实施方式，在步骤2)中，所述硅溶胶的pH值为8.5～9.0，浓度为2～4mol/L，质量分数为15～25％，密度为0.957g/cm 3。
根据本发明的一种实施方式，在步骤2)中，所述高分子聚合物溶液与硅溶胶的质量比例如可为1:1、1:2、1:3、1:4、1:5或1:6。
根据本发明的一种实施方式，在步骤2)中，混合后经搅拌得到SiO 2前驱体可纺溶胶；具体地，所述搅拌的时间可为0.5h～3h。
根据本发明的一种实施方式，在步骤3)中，所述静电纺丝的针头内径为0.50mm～0.60mm； 具体的，所述静电纺丝的参数可以为：相对湿度25％～45％，挤出速度为0.9～1.5ml/h，电压为12～16kv，接收装置与喷丝口间的距离为8～10cm，纺丝时间为1h～4h，采用金属滚筒作为接收装置，滚筒转速为40～70r/min。
根据本发明的一种实施方式，在步骤3)中，置于烘箱中去除静电，具体地，置于40～50℃烘箱中30min～1h去除静电。
根据本发明的一种实施方式，在步骤3)中，所述煅烧的程序可为：从室温升温至800℃，升温速率为5℃/min，并在800℃下保温1h。
根据本发明的一种实施方式，在步骤3)中，可在900～1300℃下煅烧，煅烧程序控制为：从室温分别升温至900～1300℃，升温速率为5℃/min，并在最高温度保温1h。
根据本发明的一种实施方式，在步骤4)中，所述疏水改性剂采用下述方法配制：将硅烷偶联剂与乙醇按照质量比3:(8～12)混合，采用0.5～2wt％稀硝酸调节混合溶液的pH值至3左右，搅拌1h～2h使其水解即获得疏水改性剂；具体地，所述硅烷偶联剂可选用KH-570、KH-550、KH-560、氯三甲基硅烷、十三氟辛基三乙氧基硅烷、十七氟癸基三乙氧基硅烷、十三氟辛基三甲氧基硅烷、十七氟癸基三甲氧基硅烷、乙酰氧基三甲基硅烷、苄基二甲基氯硅烷、苄基三氯硅烷、苄基三乙氧基硅烷、叔丁基三甲基氯硅烷、二氯异丁基甲基硅烷、正丁基三氯硅烷、环乙基三氯硅烷、3-氯环戊基硅烷或二丁基二氯化硅中的至少一种。
根据本发明的一种实施方式，在步骤4)中，所述疏水改性在真空干燥箱中进行；具体地，干燥箱温度可为40～80℃，处理时间为4h～8h。
根据本发明的一种实施方式，在步骤4)中，所述干燥在烘箱中进行；具体地，在空气气氛下进行。干燥的目的在于去除残余溶剂。具体地，干燥的温度为50～70℃，干燥的时间为6h～10h。
根据本发明的一种实施方式，上述保温隔热材料的制备方法具体包括如下步骤：
步骤1：配制高分子聚合物溶液，所述溶液由模板聚合物和水配制而成；
步骤2：配制SiO 2前驱体可纺溶胶，将上述高分子聚合物溶液与硅溶胶混合并搅拌得到SiO 2前驱体可纺溶胶；
步骤3：将上述得到的SiO 2前驱体可纺溶胶进行静电纺丝，获得模板聚合物/SiO 2复合陶瓷纳米纤维膜，并将其置于烘箱中以去除残余静电；
步骤4：将制备得的PVA/SiO 2复合陶瓷纳米纤维膜置于箱式炉中煅烧去除有机物，获得具有柔性的SiO 2陶瓷纳米纤维膜；
步骤5：将硅烷偶联剂与乙醇按照一定质量比混合，并滴加稀硝酸使其水解配制疏水改性剂；
步骤6：将SiO 2陶瓷纳米纤维膜浸泡于疏水改性剂中；
步骤7：将步骤6中湿润的SiO 2陶瓷纳米纤维取出放入真空烘箱中真空干燥以去除溶剂。
根据本发明的一种实施方式，步骤1中，模板聚合物选自PVA粉末。
根据本发明的一种实施方式，步骤1中，所述水为超纯水。
根据本发明的一种实施方式，步骤2中，所述硅溶胶为碱性硅溶胶、中性硅溶胶或酸性硅溶胶。
根据本发明的一种实施方式，步骤2中，所述高分子聚合物溶液与硅溶胶按照质量比为1:(1～6)混合，并搅拌0.5h～3h后获得前驱体溶胶。
根据本发明的一种实施方式，步骤2中，所述硅溶胶中可以加入遮光剂，目的在于增强在高温情况下的隔温性能。具体地，所述遮光剂可以包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2等中的至少一种。进一步的，二氧化钛可以是锐钛矿型二氧化钛。进一步的，二氧化钛可以是氟掺杂或者氮掺杂的二氧化钛纳米颗粒，添加这样的二氧化钛的目的在于增强红外波段辐射的遮光效果。
根据本发明的一个实施方式，步骤2中，所述硅溶胶中可以加入稀土化合物，所述稀土化合物为稀土金属盐或稀土金属氧化物，例如为钇金属盐、钪金属盐、La系金属盐(具体为钕金属盐、镱金属盐)、钇金属氧化物、钪金属氧化物、La系金属氧化物(具体为钕金属氧化物、镱金属氧化物)等中的至少一种。还例如，所述稀土化合物是两种以上的组合，具体地例如是钇金属盐和钪金属盐的组合。
根据本发明的一个实施方式，步骤2中，稀土化合物为稀土金属硝酸盐、稀土金属草酸盐、稀土金属碳酸盐中的至少一种。具体为稀土金属硝酸盐水合物，例如所述稀土化合物为Y(NO 3) 3·4H 2O、Sc(NO 3) 3·6H 2O、Nd(NO 3) 3·6H 2O、Yb(NO 3) 3·5H 2O等中的至少一种。本发明中采用硝酸盐、草酸盐或碳酸盐。
根据本发明的一种实施方式，步骤3中，静电纺丝中使用10ml注射器，静电纺丝针头的内径为0.50mm～0.60mm，静电纺丝参数为：相对湿度25％～45％，挤出速度为0.9～1.2ml/h，电压为12～16kv，接收装置与喷丝口间的距离为8～10cm，纺丝时间为1h～4h，采用金属滚筒作为接收装置，滚筒转速为40～70r/min。
根据本发明的一种实施方式，步骤3中，静电纺丝使用的针头是同轴套管针头，同轴套管针头包括内层针头和外层针头，内层针头套管在外层针头内，并保持同轴。具体的，所述内层针头流动高分子聚合物溶液，内层针头与外层针头间流动SiO 2前驱体可纺溶胶。通过同轴套筒针头，可以得到具有中空结构的纳米中空纤维。具体的，所述同轴套管针头如图6所示。
根据本发明的一种实施方式，步骤3中，将制备的PVA/SiO 2陶瓷纳米纤维膜置于40～50℃烘箱中0.5h～2h去除静电。
根据本发明的一种实施方式，所述步骤4用于去除有机物的煅烧程序为：从室温升温至800℃，升温速率为5℃/min，并在800℃下保温1h。此外，将SiO2陶瓷纳米纤维膜置于900～1300℃下煅烧，煅烧程序控制为：从室温分别升温至900～1300℃，升温速率为5℃/min，并在最高温度保温1h。
根据本发明的一种实施方式，所述步骤5中的硅烷偶联剂选用KH-550、KH-560、KH-570、氯三甲基硅烷、十三氟辛基三乙氧基硅烷、十七氟癸基三乙氧基硅烷、十三氟辛基三甲氧基硅烷、十七氟癸基三甲氧基硅烷、乙酰氧基三甲基硅烷、苄基二甲基氯硅烷、苄基三氯硅烷、苄基三乙氧基硅烷、叔丁基三甲基氯硅烷、二氯异丁基甲基硅烷、正丁基三氯硅烷、环乙基三氯硅烷、3-氯环戊基硅烷或二丁基二氯化硅中的一种。
根据本发明的一种实施方式，步骤5中，硅烷偶联剂与溶剂按照质量比1:(1～5)混合，采用1wt％稀硝酸调节混合溶液的pH值至3左右，搅拌2h使其水解获得疏水改性剂；具体地，所述溶剂可选用正己烷、乙醇、四氢呋喃、N，N-二甲基甲酰胺、N，N-二甲基乙酰胺、氯仿、二氯甲烷、甲醇、四氯化碳、嘧啶、二甲苯、环己烷、甲乙酮或乙酸甲酯中的至少一种。
根据本发明的一种实施方式，步骤6中，所述改性在烘箱中进行，具体地，烘箱温度为60℃，处理时间为6h～8h。
根据本发明的一种实施方式，步骤7中，干燥的温度为50～70℃，干燥时间为6h～10h。
[保温隔热复合材料]
本发明还提供一种保温隔热复合材料，所述复合材料是上述保温隔热材料与二氧化硅气凝胶或稀土掺杂二氧化硅气凝胶的复合物。
根据本发明的一种实施方式，所述复合材料是上述保温隔热材料与二氧化硅气凝胶的复合物；具体地，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述二氧化硅气凝胶作为填料。
根据本发明的一种实施方式，所述复合材料是上述保温隔热材料与稀土掺杂二氧化硅气 凝胶的复合物；具体地，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述稀土掺杂二氧化硅气凝胶作为填料。
根据本发明的一种实施方式，所述气凝胶中进一步包括硅微粉。
具体地，所述硅微粉粒径范围是600目-1500目。
具体地，所述硅微粉可以是晶态二氧化硅粉粒，也可以是非晶态(无定型)二氧化硅粉粒。
研究发现，利用硅微粉，特别是非晶态二氧化硅粉粒在高温情况下的晶相变化导致的体积变化，调整和抑制绝热材料在高温下的收缩情况，同时非晶态硅微粉还可以提升绝热材料的温度耐受能力。非晶态硅微粉是二氧化硅材料，在温度变化下会有晶型的转变带来的体积变化的现象。非晶态硅微粉体积的膨胀在绝热材料经历高温过程中会抑制和降低内应力，从而减少绝热材料内部的结构变化而稳定其在高温情况下的隔热保温性能。硅微粉在高温并含有铝元素的情况下，会向莫来石方向进行反应和转变，莫来石是一种优秀的耐火材料，因此硅微粉的加入进一步提高了保温绝热材料的耐高温能力。
进一步地，非晶态硅微粉的粒径是800-8000目、1000-2000目、2000-3000目、3000-4000目、4000-5000目、5000-6000目、6000-7000目、7000-8000目、1000-1500目、1500目-3000目，或10-800nm、10-100nm、50-200nm、100-400nm、300-800nm。优选的粒径是800-1000目、1000-1200目、1000-3000目。
进一步地，硅微粉添加量是3-25wt％、1-10wt％、3-15wt％、5-20wt％、5-25wt％、10-25wt％，优选的添加量是2-10wt％、3-8wt％、3-6wt％。非晶态硅微粉的添加量为1-20wt％、1-15wt％、2-10wt％、3-8wt％。优选的粒径可以更好的促进硅、铝和氧键的结合，使得结构更加稳定。优选的添加量可以更好的提升材料在高温的抗收缩的能力，同时保持较高的隔热性能与机械强度。
根据本发明的一种实施方式，所述气凝胶中进一步包括遮光剂。具体地，所述遮光剂可以包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2等中的至少一种。进一步的，二氧化钛可以是锐钛矿型二氧化钛。进一步的，二氧化钛可以是氟掺杂或者氮掺杂的二氧化钛纳米颗粒。
[保温隔热复合材料的制备方法]
本发明还提供一种上述保温隔热复合材料的制备方法，所述方法包括以下步骤：
S1.制备硅溶胶：将硅源、水、醇溶剂混合制备硅溶胶；
S2.制备稀土硅溶胶：配置稀土化合物溶液，并将稀土化合物溶液与上述硅溶胶混合，得 到稀土硅溶胶；
S3.制备纤维预制件，包括以下步骤：
S3-1.配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
S3-2.配制SiO 2前驱体可纺溶胶：将步骤S3-1中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；
S3-3.制备纤维预制件：将步骤S3-2的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到纤维预制件；
S4.纤维预制件改性：采用疏水改性剂对步骤S3中的纤维预制件进行疏水改性处理，干燥，得到具有疏水性能的纤维预制件；
S5.制备凝胶：向步骤S1的硅溶胶或步骤S2的稀土硅溶胶中加入凝胶催化剂后，将其浇筑至步骤S3的纤维预制件或步骤S4的具有疏水性能的改性纤维预制件中，静置，获得凝胶；
S6.干燥：对步骤S5的凝胶进行干燥，得到所述保温隔热复合材料。
根据本发明的一种实施方式，步骤S1具体包括：将硅源、水、醇溶剂、硅微粉混合制备硅溶胶。具体地，可以向硅溶胶中加入水解催化剂，以加速硅源水解，更快获得硅溶胶。具体地，所述硅源可选用硅酸钠、正硅酸乙酯、正硅酸甲酯、四丙氧基硅烷、四丁氧基硅烷、二甲基二甲氧基硅烷或二甲基二乙氧基硅烷或其组合。具体地，所述硅微粉具有上文所述定义。具体地，所述水解催化剂可选用盐酸、草酸、硝酸、硫酸、磷酸或其组合。具体地，所述醇溶剂可选用甲醇、乙醇或其组合。
根据本发明的一种实施方式，步骤S1的硅溶胶中还可以加入遮光剂，目的在于增强在高温情况下的隔温性能。具体地，所述遮光剂包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2等中的至少一种。进一步的，二氧化钛可以是锐钛矿型二氧化钛。进一步的，二氧化钛可以是氟掺杂或者氮掺杂的二氧化钛纳米颗粒，选择这样的二氧化钛的目的在于增强红外波段辐射的遮光效果。
根据本发明的一个实施方式，步骤S1中的硅溶胶中还可以加入稀土化合物，所述稀土化合为稀土金属盐或稀土金属氧化物，例如为钇金属盐、钪金属盐、La系金属盐(具体为钕金属盐、镱金属盐)、钇金属氧化物、钪金属氧化物、La系金属氧化物(具体为钕金属氧化物、镱金属氧化物)等中的至少一种。还例如，所述稀土化合物是两种以上的组合，具体地例如是钇金属盐和钪金属盐的组合。
根据本发明的一个实施方式，步骤S1中，所述稀土化合物为稀土金属硝酸盐、稀土金属 草酸盐、稀土金属碳酸盐中的至少一种。具体为稀土金属硝酸盐水合物，例如所述稀土化合物为Y(NO 3) 3·4H 2O、Sc(NO 3) 3·6H 2O、Nd(NO 3) 3·6H 2O、Yb(NO 3) 3·5H 2O等中的至少一种。本发明中采用硝酸盐、草酸盐或碳酸盐。离子的引入，进一步实现了气凝胶中卤素离子的含量控制。
根据本发明的一种实施方式，步骤S2中，配置稀土化合物溶液的具体过程包括：将稀土化合物溶于水中，加热反应后，冷却至室温后得到稀土化合物溶液。
根据本发明的一个实施方式，步骤S2中，所述稀土化合物为稀土金属盐或稀土金属氧化物，例如为钇金属盐、钪金属盐、La系金属盐(具体为钕金属盐、镱金属盐)、钇金属氧化物、钪金属氧化物、La系金属氧化物(具体为钕金属氧化物、镱金属氧化物)等中的至少一种。还例如，所述稀土化合物是两种以上的组合，具体地例如是钇金属盐和钪金属盐的组合。
根据本发明的一个实施方式，步骤S2中，所述稀土化合物为稀土金属硝酸盐、稀土金属草酸盐、稀土金属碳酸盐中的至少一种。具体为稀土金属硝酸盐水合物，例如所述稀土化合物为Y(NO 3) 3·4H 2O、Sc(NO 3) 3·6H 2O、Nd(NO 3) 3·6H 2O、Yb(NO 3) 3·5H 2O等中的至少一种。本发明中采用硝酸盐、草酸盐或碳酸盐，避免了卤素离子的引入，进一步实现了气凝胶中卤素离子的含量控制。
根据本发明的一个实施方式，步骤S2的配置稀土化合物溶液的过程中，采用水浴加热。加热的温度可以为40℃～60℃，例如为45～50℃；加热的时间可以为20min～60min，例如加热的时间可为30min～35min。
根据本发明的一个实施方式，在步骤S2的配置稀土化合物溶液的过程中，所述稀土硝酸盐与水的质量比可为(3～4):1。
根据本发明的一种实施方式，在步骤S3-1中，所述模板聚合物例如选自PVA粉末；具体地，所述PVA粉末可采用1788型。
根据本发明的一种实施方式，在步骤S3-1中，所述高分子聚合物溶液的质量分数可为10％～12％。
根据本发明的一种实施方式，在步骤S3-1中，所述水可采用超纯水。
根据本发明的一种实施方式，在步骤S3-1中，所述配制高分子聚合物溶液可通过搅拌6h～8h使PVA粉末完全溶解于水中。
根据本发明的一种实施方式，在步骤S3-1中，所述硅溶胶的pH值为8.5～9.0，浓度为 2～4mol/L，质量分数为15～25％，密度为0.957g/cm 3。
根据本发明的一种实施方式，在步骤S3-2中，所述高分子聚合物溶液与硅溶胶的质量比例如可为1:1、1:2、1:3、1:4、1:5或1:6。
根据本发明的一种实施方式，在步骤S3-2中，混合后经搅拌得到SiO 2前驱体可纺溶胶；具体地，所述搅拌的时间可为0.5h～3h。
根据本发明的一种实施方式，在步骤S3-3中，所述静电纺丝的针头内径为0.50mm～0.60mm；具体的，所述静电纺丝的参数可以为：相对湿度25％～45％，挤出速度为0.9～1.5ml/h，电压为12～16kv，接收装置与喷丝口间的距离为8～10cm，纺丝时间为1h～4h，采用金属滚筒作为接收装置，滚筒转速为40～70r/min。
根据本发明的一种实施方式，在步骤S3-3中，置于烘箱中去除静电，具体地，置于40～50℃烘箱中30min～1h去除静电。
根据本发明的一种实施方式，在步骤S3-3中，所述煅烧的程序可为：从室温升温至800℃，升温速率为5℃/min，并在800℃下保温1h。
根据本发明的一种实施方式，在步骤S3-3中，可在900～1300℃下煅烧，煅烧程序控制为：从室温分别升温至900～1300℃，升温速率为5℃/min，并在最高温度保温1h。
根据本发明的一种实施方式，在步骤S4中，所述疏水改性剂采用下述方法配制：将硅烷偶联剂与乙醇按照质量比3:(8～12)混合，采用0.5～2wt％稀硝酸调节混合溶液的pH值至3左右，搅拌1h～2h使其水解即获得疏水改性剂；具体地，所述硅烷偶联剂可选用KH-570、KH-550、KH-560、氯三甲基硅烷、十三氟辛基三乙氧基硅烷、十七氟癸基三乙氧基硅烷、十三氟辛基三甲氧基硅烷、十七氟癸基三甲氧基硅烷、乙酰氧基三甲基硅烷、苄基二甲基氯硅烷、苄基三氯硅烷、苄基三乙氧基硅烷、叔丁基三甲基氯硅烷、二氯异丁基甲基硅烷、正丁基三氯硅烷、环乙基三氯硅烷、3-氯环戊基硅烷或二丁基二氯化硅中的至少一种。
根据本发明的一种实施方式，在步骤S4中，所述疏水改性在真空干燥箱中进行；具体地，干燥箱温度可为40～80℃，处理时间为4h～8h。
根据本发明的一种实施方式，在步骤S4中，所述干燥在烘箱中进行；具体地，在空气气氛下进行。干燥的目的在于去除残余溶剂。具体地，干燥的温度为50～70℃，干燥的时间为6h～10h。
根据本发明的一种实施方式，步骤S5中，在加入凝胶催化剂后，还可以再加入增强纤维以及纤维分散剂。具体地，所述纤维分散剂可以是十二烷基磺酸钠、聚乙二醇、十二烷基硫 酸钠、六偏磷酸钠等中的至少一种。本发明中，加入凝胶催化剂使得稀土硅溶胶转变为稀土掺杂凝胶，具体的，所述凝胶催化剂可以是氨水、二甲基甲酰胺、氨水乙醇稀释液等中的一种或多种。
根据本发明的一种实施方式，步骤S6中，所述干燥的方法可以是常温常压干燥、临界干燥、超临界干燥等。
具体地，所述临界干燥、超临界干燥的干燥介质可选用CO 2、甲醇、乙醇中的至少一种。
具体地，所述常温常压干燥的条件可以是，分别在60、80和120℃干燥2h，得到最终产品。
具体地，所述二氧化碳超临界干燥的条件是，在溶剂是乙醇的情况下，在5℃，5.5MPa下用液态二氧化碳浸泡3天，并放出置换出的乙醇；然后升温至35℃，10.5MPa并保持3h，然后以0.5MPa/h的速度缓慢泄压至常压，得到最终产品。
具体地，所述乙醇超临界干燥的条件是，按预设程序升温升压至临界点后，在恒定温度状态下，以缓慢的速度释放反应釜内部的流体，直至内外压力平衡。升温前可以使用N2预先充满反应釜，预充N2的压力为1-4MPa，升温至240℃以上，升温速率0.5-2℃/min，当压力超过8MPa后，开启冷却装置，缓慢泄压，泄压至常压后通入N 2吹扫反应釜，待冷却至室温后，得到最终产品。
[保温隔热材料或保温隔热复合材料的应用]
本发明还提供所述保温隔热材料或保温隔热复合材料的应用，其可以用于高温潮湿环境下的保温隔热。
根据本发明的一个实施方式，由于所述保温隔热材料具备的柔性以及低导热系数，可用在空间受限条件下的保温。
[防排烟风管]
本发明还提供一种防排烟风管，所述防排烟风管包括金属管道，金属管道的内壁和/或外壁设置有热屏蔽层，所述热屏蔽层包括绝热层，所述绝热层中包括上述的保温隔热材料或上述的保温隔热复合材料，或者，所述绝热层包含骨架、填料、抗收缩添加剂和耐高温添加剂。
根据本发明的一种实施方式，所述热屏蔽层还包括导热层、热反射层中的至少一种。
根据本发明的一种实施方式，所述填料包括二氧化硅气凝胶、硅酸铝气凝胶、氧化铝气凝胶、复合二氧化硅气凝胶、稀土掺杂二氧化硅气凝胶的至少一种。示例性地，填料具有核壳结构，其中，外壳是硅酸铝和/或氧化铝气凝胶、内核是二氧化硅气凝胶，或者外壳是二氧化硅气凝胶、内核是硅酸铝和/或氧化铝气凝胶。或者，所述气凝胶可以是二氧化硅与氧化铝 复合的二氧化硅/氧化铝复合气凝胶。
进一步地，所述骨架由纤维材料制成，纤维材料可以是硅酸铝纤维、氧化铝纤维、玻璃纤维、莫来石纤维、SiO 2陶瓷纳米纤维的至少一种。
进一步地，所述耐高温添加剂可以是硅酸铝、石英粉、硅微粉等。
下面结合具体的实施例，进一步地说明本发明中的技术方案，这些实施例仅是用来提供对本发明的进一步理解，且作为构成说明书的一部分，与上述的附图一起用于解释本发明，但并不构成对本发明的限制。此外应理解，在阅读本发明讲授的内容之后，本领域技术人员可以对本发明作各种改动或修改，这些等价形式同样落于本申请的范围。
本发明实施例采用静电纺丝技术，硅溶胶为主要原料，聚乙烯醇为纺丝助剂，所述保温隔热材料的具体制备方法包括以下步骤：
1.配制高分子聚合物溶液，所述溶液由PVA粉末与超纯水配制而成；PVA粉末采用1788型，配制的聚合物溶液的质量分数为10～12％，通过搅拌6～8h使PVA粉末完全溶解于水中。
2.配制SiO 2前驱体可纺溶胶，将聚合物溶液与硅溶胶混合并搅拌均匀得到具有电纺丝性能的前驱体溶胶；硅溶胶的pH值8.5～9.0，浓度为3.19mol/L，质量分数为19.1％，密度为0.957g/cm 3。PVA水溶液与硅溶胶按照质量比为1:(1～6)混合，并搅拌0.5～3h后获得前驱体溶胶。
3.将得到的SiO 2前驱体进行静电纺丝，获得PVA/SiO 2复合陶瓷纳米纤维膜，并将其置于烘箱中以去除残余静电；静电纺丝使用的10mL注射器，静电纺丝针头内径0.50～0.60mm，静电纺丝参数为：相对湿度25％～45％，挤出速度为0.9～1.5ml/h，电压为12～16kv，接收装置与喷丝口间的距离为8～10cm，纺丝时间为1h～4h，采用金属滚筒作为接收装置，滚筒转速为40～70r/min。将制备的PVA/SiO 2陶瓷纳米纤维膜置于40～50℃烘箱中30min～1h去除静电。
4.将制备得的PVA/SiO 2复合陶瓷纳米纤维膜置于箱式炉中煅烧去除有机物，获得具有柔性的SiO 2陶瓷纳米纤维膜；用于去除有机物的煅烧程序为：从室温升温至800℃，升温速率为5℃/min，并在800℃下保温1h。此外，将SiO 2陶瓷纳米纤维膜置于900～1300℃下煅烧，煅烧程序控制为：从室温分别升温至900～1300℃，升温速率为5℃/min，并在最高温度保温1h。
5.将硅烷偶联剂与乙醇按照一定质量比混合，并滴加稀硝酸使其水解配制疏水改性剂；配制疏水改性剂的硅烷偶联剂选用KH-570。硅烷偶联剂与乙醇按照质量比3:10混合，采用1wt％稀硝酸调节混合溶液的PH值至3左右，搅拌2h使其水解获得疏水改性剂。
6.将SiO 2陶瓷纳米纤维膜浸泡于疏水改性剂中；改性时置于真空干燥箱中，干燥箱温度为60℃，处理时间为4～8h。
7.将步骤6中湿润的SiO 2陶瓷纳米纤维取出放入烘箱中，在空气气氛下干燥去除残余溶剂。干燥的温度为50～70℃，干燥时间为6～10h。
以下给出具体实施例。应当理解，以下所描述的具体实施例仅仅用于解释本发明，并不用于限定本发明。
实施例1
如图1，本实施例提供一种保温隔热材料，其制备方法包括如下步骤：
1)在室温下，称取5g的聚乙烯醇粉末溶解在45g的超纯水中，配制质量分数为10wt％的聚合物溶液；
2)在室温下，将5g的上述聚合物溶液和10g中性硅溶胶(聚合物溶液与硅溶胶按质量比1:2)混合搅拌2h，获得静电纺丝的前驱体溶胶；
3)将上述纺丝液装入10ml的注射器中，采用内径为0.50mm的喷丝针头，静电纺丝时控制湿度为35％，设备工作电压为14kV，注射速率为1.1ml/h，以锡纸滚筒为接收装置，转速为50r/min，喷丝针头与锡纸间的距离为10cm，进行静电纺丝以制备PVA/SiO 2复合纳米纤维膜；
4)将步骤3)得到的PVA/SiO 2复合纳米纤维膜置于50℃烘箱中30min，用以去除静电，便于保存以及接下的操作；
5)将上述的PVA/SiO 2复合纳米纤维膜从锡纸上揭下，并置于箱式炉中在空气气氛下煅烧从而去除有机成分得到具有柔性得SiO 2陶瓷纳米纤维，煅烧过程的参数为：从室温升温至800℃，其中升温速率为5℃/min，并且在800℃下保温1h；
6)在室温下，将6g的硅烷偶联剂(KH-570)加入到20g乙醇中，搅拌使其混合并逐滴加入1wt％稀硝酸，调节混合溶液pH至3，再搅拌2h使硅烷偶联剂充分水解从而得到疏水改性剂；
7)将步骤5)中SiO 2陶瓷纳米纤维膜浸泡于步骤6)配制的疏水改性剂，并置于60℃真空干燥箱中4h；
8)将步骤7)中SiO 2陶瓷纳米纤维膜从疏水改性剂中取出，重新置于60℃烘箱中干燥8h去除溶剂获得具有疏水性能的SiO 2陶瓷纳米纤维膜、即本发明的保温隔热材料；
9)上述制备的SiO 2陶瓷纳米纤维膜内部为陶瓷纤维组成的三维互穿网络结构，陶瓷纤维的平均直径为313nm，导热系数为0.053W/mK。
图2为实施例1制备的SiO 2陶瓷纳米纤维膜的SEM图像。图3为实施例1制备的SiO 2陶瓷纳米纤维膜的TG曲线。图4为实施例1制备的疏水改性的SiO 2陶瓷纳米纤维膜。
实施例2
研究不同PVA用量对保温隔热材料的性能的影响。
采用实施例1同样的方法制备保温隔热材料，其中PVA用量具体如表1所示。
表1中还给出了不同PVA用量SiO 2陶瓷纳米纤维膜的密度、纤维平均直径和导热系数。从表1可见，优选的，在10wt％PVA溶液与硅溶胶在1:2的情况下，SiO 2陶瓷纳米纤维膜的导热系数最低，保温性能最好；硅溶胶的占比越高，SiO 2陶瓷纳米纤维膜的密度越高。
表1.不同PVA用量保温隔热材料(热处理温度800℃)的物理性质表
Figure PCTCN2022119048-appb-000001
表2中给出了不同PVA含量制备的保温隔热材料的拉伸强度，从表2可见，在10wt％PVA溶液与硅溶胶在1:2的情况下，保温隔热材料的拉伸强度优于其他配比，保温隔热材料的抗拉伸性能最好。
表2.不同PVA含量制备的保温隔热材料的拉伸强度
样品10wt％PVA溶液与硅溶胶的质量比 拉伸强度(MPa)
1:1 2.01
1:2 4.15
1:3 1.17
1:4 0.86
1:5 0.54
1:6 0.51
表3给出了不同热处理后保温隔热材料的拉伸强度，从表3可见，10wt％PVA溶液与硅溶胶的质量比为1:2，在不同热处理后拉伸强度不同，在900℃的热处理条件下，保温隔热材料拉伸强度最高，材料的抗拉伸性能最好。
表3.不同温度热处理后SiO 2陶瓷纳米纤维膜的拉伸强度样品的10wt％PVA溶液与硅溶胶的质量比为1:2
热处理温度 拉伸强度(MPa)
800℃ 2.04
900℃ 4.15
1000℃ 2.85
1100℃ 2.10
1200℃ 0.58
实施例3
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤2)中采用7g的10wt％PVA水溶液和7g的硅溶胶(10wt％PVA与硅溶胶的质量比为1:1)均匀混合形成静电纺丝前驱体溶胶。所述制备的SiO 2陶瓷纳米纤维膜平均直径263nm，导热系数为0.063W/mK。
实施例4
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤2)中采用5g的10wt％PVA水溶液和10g的硅溶胶(10wt％PVA与硅溶胶的质量比为1:2)均匀混合形成静电纺丝前驱体溶胶。所述制备的SiO 2陶瓷纳米纤维膜平均直径283nm，导热系数为0.053W/mK。
实施例5
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤2)中采用2g的10wt％PVA水溶液和10g的硅溶胶(10wt％PVA与硅溶胶的质量比为2:5)均匀混合形成静电纺丝前驱体溶胶。所述制备的SiO 2陶瓷纳米纤维膜平均直径350nm。
实施例6
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤3)替换为：将上述纺丝液装入10ml的注射器中，采用内径为0.60mm的喷丝针头，静电纺丝时控制湿度为25％，设备工作电压为16kV，注射速率为1.5ml/h，以锡纸滚筒为接收装置，转速为60r/min，喷丝针头与锡纸间的距离为8cm，进行静电纺丝以制备PVA/SiO 2复合纳米纤维膜。所述PVA/SiO 2复合纳米纤维膜平均直径315nm，去除有机物后的SiO 2陶瓷纳米纤维膜平均纤维直径298nm，导热系数为0.054W/mK。
实施例7
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤5)中煅烧温度选取900℃，其煅烧过程的控制参数为：从室温升温至900℃，升温速率为5℃/min，并在900℃的最终温度保温2h。在900℃煅烧去除有机物的SiO 2陶瓷纳米纤维膜的纤维互穿网络相比实施例1拉伸断裂强度升高，从2.037MPa升至4.145MPa。
实施例8
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤7)中将步骤5)中SiO 2陶瓷纳米纤维膜浸泡于步骤6)配制的疏水改性剂，并置于60℃真空干燥箱中改性处理8h。而后置于60℃烘箱中，在空气气氛下干燥10h，获得具有良好疏水性能的SiO 2陶瓷纳米纤维膜。
实施例9
本实施提供一种保温隔热材料，其制备方法与实施例1不同在于，步骤3)中将静电纺丝制备成型的PVA/SiO 2复合纳米纤维膜进行多层叠放，叠放后进行层压或者热压，制备成毡状材料。
实施例10
本实施例提供一种保温隔热材料，其制备方法包括如下步骤：
1)在室温下，称取5g的聚乙烯醇粉末溶解在45g的超纯水中，配制质量分数为10wt％的聚合物溶液；
2)在室温下，将5g的上述聚合物溶液和10g中性硅溶胶(聚合物溶液与硅溶胶按质量比1：2)混合搅拌2h，获得静电纺丝的前驱体溶胶；
3)将上述纺丝液装入10ml的注射器中，采用内径为0.50mm的喷丝针头，静电纺丝时控制湿度为35％，设备工作电压为14kV，注射速率为1.1ml/h，以锡纸滚筒为接收装置，转速为50r/min，喷丝针头与锡纸间的距离为10cm，进行静电纺丝以制备PVA/SiO2复合纳米纤维膜；
4)将步骤3)得到的PVA/SiO2复合纳米纤维膜置于50℃烘箱中30min，用以去除静电，便于保存以及接下的操作；
5)将上述的PVA/SiO2复合纳米纤维膜从锡纸上揭下，并置于箱式炉中在空气气氛下煅烧从而去除有机成分得到具有柔性得SiO2陶瓷纳米纤维，煅烧过程的参数为：从室温升温至800℃，其中升温速率为5℃/min，并且在800℃下保温1h；
6)在室温下，将6g的硅烷偶联剂(KH-570)加入到20g乙醇中，搅拌使其混合并逐滴加入1wt％稀硝酸，调节混合溶液PH至3，再搅拌2h使硅烷偶联剂充分水解从而得到疏水改性剂；
7)将步骤5)中SiO2陶瓷纳米纤维膜浸泡于步骤6)配制的疏水改性剂，并置于60℃烘箱中4h；
8)将步骤7)中SiO2陶瓷纳米纤维膜从疏水改性剂中取出，重新置于60℃烘箱中干燥8h去除溶剂获得具有疏水性能的SiO2陶瓷纳米纤维膜；
9)上述制备的SiO2陶瓷纳米纤维膜内部为陶瓷纤维组成的三维互穿网络结构，陶瓷纤维 的平均直径为338nm。
实施例11
本实施提供了一种保温隔热材料，其制备方法与实施例10不同在于，步骤5)中煅烧温度选取900℃，其煅烧过程的控制参数为：从室温升温至900℃，升温速率为5℃/min，并在900℃的最终温度保温两小时。在900℃煅烧去除有机物的SiO2陶瓷纳米纤维膜的纤维互穿网络相比实施例1拉伸断裂强度升高，从2.037MPa升至4.145MPa。
实施例12
本实施例提供一种保温隔热复合材料，其制备方法包括以下步骤：
(1)硅溶胶制备：将硅源、水、醇溶剂、硅微粉混合制备硅溶胶，向硅溶胶中加入水解催化剂加速硅源水解，更快获得硅溶胶。硅源可选用硅酸钠、正硅酸乙酯、正硅酸甲酯、四丙氧基硅烷、四丁氧基硅烷、二甲基二甲氧基硅烷或二甲基二乙氧基硅烷或其组合。硅微粉粒径范围是600目-1500目。水解催化剂可选用盐酸、草酸、硝酸、硫酸、磷酸或其组合。醇溶剂可选用甲醇、乙醇或其组合。硅溶胶中还可以加入遮光剂增强在高温情况下的隔温性能，遮光剂包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2等。进一步的，二氧化钛可以是锐钛矿型二氧化钛。进一步的，二氧化钛可以是氟掺杂或者氮掺杂的二氧化钛纳米颗粒，增强红外波段辐射的遮光效果。
(2)稀土硅溶胶制备：将稀土化合物制备成稀土溶液，并将稀土溶液与硅溶胶混合，得到稀土硅溶胶。稀土化合物可选用钇金属盐、钪金属盐、钕金属盐、镱金属盐；钇金属氧化物、钪金属氧化物、钕金属氧化物、镱金属氧化物。
进一步的，钇金属盐可以是硝酸钇、氯化钇、草酸钇、碳酸钇；钪金属盐可以是硝酸钪、氯化钪、草酸钪、碳酸钪；钕金属盐可以是硝酸钕、氯化钕、草酸钇、碳酸钕；镱金属盐可以是硝酸镱、氯化镱、草酸镱、碳酸镱。
进一步的，稀土溶液中可以包含一种或一种上述稀土化合物。
(3)纤维预制件制备：配制高分子聚合物溶液，所述溶液有PVA粉末与超纯水配制而成；配制SiO2前驱体可纺溶胶，将聚合物溶液与硅溶胶混合并搅拌均匀得到具有电纺丝性能的前驱体溶胶；将上述得到的SiO2前驱体进行静电纺丝，获得PVA/SiO2复合陶瓷纳米纤维膜，并将其置于烘箱中以去除残余静电；将制备得的PVA/SiO2复合陶瓷纳米纤维膜置于箱式炉中煅烧去除有机物，获得具有柔性的SiO2陶瓷纳米纤维。
(4)纤维预制件改性：将SiO2陶瓷纳米纤维膜浸泡于疏水改性剂中，疏水改性剂含有硅 烷偶联剂与乙醇，浸泡后对SiO2陶瓷纳米纤维膜进行真空干燥。
(5)凝胶制备：向稀土硅溶胶中加入凝胶催化剂后，并将其浇筑至改性纤维预制件中，之后静置24-72h获得凝胶。
进一步的，还可以在加入凝胶催化剂后，再加入增强纤维以及纤维分散剂。纤维分散剂可以是十二烷基磺酸钠、聚乙二醇、十二烷基硫酸钠、六偏磷酸钠等。
加入凝胶催化剂使得稀土硅溶胶转变为稀土掺杂凝胶，凝胶催化剂是氨水、二甲基甲酰胺、氨水乙醇稀释液等。
(6)干燥：对稀土掺杂凝胶进行干燥，得到稀土掺杂气凝胶-陶瓷纳米纤维复合材料。干燥的方法可以是常温常压干燥、临界干燥、超临界干燥等。临界干燥、超临界干燥的干燥介质可选用CO2、甲醇、乙醇。得到的稀土掺杂气凝胶-陶瓷纳米纤维复合材料可以作为绝热层。
常温常压干燥的条件是，分别在60、80和120℃干燥2h，最后得白色SiO 2气凝胶粉末。
二氧化碳超临界干燥的条件是，在溶剂是乙醇的情况下，在5℃，5.5MPa下用液态二氧化碳浸泡3天，并放出置换出的乙醇；然后升温至35℃，10.5MPa并保持3h，然后以0.5MPa/h的速度缓慢泄压至常压，即得到最终产品。
乙醇超临界干燥的条件是，按预设程序升温升压至临界点后，在恒定温度状态下，以缓慢的速度释放反应釜内部的流体，直至内外压力平衡。升温前可以使用N 2预先充满反应釜，预充N 2的压力为1-4MPa，升温至240℃以上，升温速率0.5-2℃/min，当压力超过8MPa后，开启冷却装置，缓慢泄压，泄压至常压后通入N 2吹扫反应釜，待冷却至室温后，得到最终产品。
实施例13
本发明还提供一种防排烟风管，所述防排烟风管包括金属管道，金属管道的内壁和/或外壁设置有热屏蔽层，所述热屏蔽层包括绝热层，所述绝热层中包括上述的保温隔热材料或上述的保温隔热复合材料，或者，所述绝热层包含骨架、填料、抗收缩添加剂和耐高温添加剂。
根据本发明的一种实施方式，所述热屏蔽层还包括导热层、热反射层中的至少一种。
根据本发明的一种实施方式，所述填料包括二氧化硅气凝胶、硅酸铝气凝胶、氧化铝气凝胶、复合二氧化硅气凝胶、稀土掺杂二氧化硅气凝胶的至少一种。示例性地，填料具有核壳结构，其中，外壳是硅酸铝和/或氧化铝气凝胶、内核是二氧化硅气凝胶，或者外壳是二氧化硅气凝胶、内核是硅酸铝和/或氧化铝气凝胶。或者，所述气凝胶可以是二氧化硅与氧化铝复合的二氧化硅/氧化铝复合气凝胶。
进一步地，所述骨架由纤维材料制成，纤维材料可以是硅酸铝纤维、氧化铝纤维、玻璃 纤维、莫来石纤维、SiO 2陶瓷纳米纤维的至少一种。
进一步地，所述耐高温添加剂可以是硅酸铝、石英粉、硅微粉等。
进一步地，所述防排烟风管具备快速连接功能，具体的，所述防排烟风管由前风管单元和后风管单元快速拼接而成。每个风管单元的主体结构包括金属主体框架、与框架内壁贴合的内壁热屏蔽层，与框架外壁贴合的外壁热屏蔽层，以及外壁热屏蔽层外侧相贴合的耐火密封胶。其中，所述内壁热屏蔽层、金属主体框架、外壁热屏蔽层、外侧耐火密封胶依次覆盖连接，连接方式可以为铆钉固定、粘连等物理或化学连接方法。内壁热屏蔽层与外壁热屏蔽层可由绝热层以及导热层和热反射层中的单层或多层构成。此外，为使风管单元间能够紧密相连，实现密闭、隔热、防止热桥的功能，每个风管单元的两端分别设有延伸层与接收区域。
进一步地，所述防排烟风管包括前风管、后风管、安装座、定位杆和定位筒；所述前风管一端可拆卸连接有所述后风管；所述安装座对称设于所述前风管和所述后风管的侧面，所述定位杆和所述定位筒对应设于两侧安装座的相对侧面，且所述定位杆和所述定位筒滑动配合；所述前风管内壁和/或外壁设置有热屏蔽层，所述后风管内壁和/或外壁设置有热屏蔽层；所述热屏蔽层包括绝热层以及导热层、热反射层中的至少一种；所述绝热层与所述前风管、后风管的内壁和/或外壁贴合。
进一步地，所述防排烟风管包括前风管、后风管；所述前风管一端可拆卸连接有所述后风管；所述前风管、后风管两端分别设有角钢法兰；所述前风管内壁和/或外壁设置有热屏蔽层，所述后风管内壁和/或外壁设置有热屏蔽层；所述热屏蔽层包括绝热层以及导热层和热反射层中的至少一种；所述绝热层与所述前风管、后风管的内壁和/或外壁贴合。
优选的，上述连接组件包括：金属或其他耐高温材料制成的环绕式固定箍120、螺栓121、螺母122，如图7所示。其中环绕式固定箍120还包括限位孔，环绕式固定箍120的宽度不小于风管延伸出的外壁热屏蔽层200及的长度。
两个风管单元连接后的固定方式可以为：环绕式固定箍120覆盖住两个风管单元金属管道100与热屏蔽层200连接的缝隙，螺栓121穿过相应的限位孔，并用螺母122旋紧固定。
上述技术方案，提供了一种可以快速连接固定、具有隔热功能的防排烟风管结构。实现了防排烟风管之间的快速连接，提高了工作效率，同时保证了风管的防排烟密闭性及耐火性能不会下降，实用性较强。本技术方案可实现两个风管之间的快速连接，提高了工作效率，同时保证了风管的防排烟密闭性及耐火性能不会下降，实用性较强。
进一步地，本发明提供了一个技术方案，发明人通过对复合的二氧化硅/硅酸铝气凝胶颗 粒或二氧化硅/氧化铝气凝胶颗粒中的二氧化硅气凝胶部分做了进一步的改性和优化，虽然二氧化硅气凝胶与含铝气凝胶进行了复合，但是在高温情况下二氧化硅气凝胶部分本身也有可能出现收缩坍塌的问题，发明人向二氧化硅气凝胶中加入抗收缩添加剂(例如硅微粉)，通过硅微粉在高温下的晶型变化、体积变化，可以抑制和减少二氧化硅气凝胶的收缩坍塌问题，进一步提高复合二氧化硅/硅酸铝气凝胶颗粒或复合二氧化硅/氧化铝气凝胶颗粒的耐温性能，进一步提高复合气凝胶的耐温性能，增强绝热层性能从而改善防排烟耐火通风管道的高温表现。
应用增强的气凝胶材料于防排烟风管中，如加入了复合二氧化硅/硅酸铝气凝胶颗粒或复合二氧化硅/氧化铝气凝胶颗粒的绝热层，可以在实现较低的传热系数同时承受高温，使得气凝胶材料可以应用于防排烟风管的领域中，增强防排烟风管的耐热能力，在火灾发生时候使得防排烟风管正常的发挥作用。应用气凝胶隔热材料于防排烟风管中，还可以减少隔热材料的空间占用。
本技术方案还可以解决现有技术中防排烟风管使用的隔热材料会出现吸水导致隔热结构坍塌、寿命短，同时由于导热系数高的原因导致占用空间较大的问题。在实际中火场风管在局部受热的情况下，还会出现风管结构变化坍塌、风管出现缺陷，导致管内风压变化、漏风，也会使得风管排风性能下降。气凝胶的体积在高温情况下(800摄氏度以上)会发生体积收缩的现象，导致结构变化而降低隔热保温性能。本发实施例要解决的技术问题是绝热层材料在高温情况下，会发生内部二氧化硅微观结构收缩和坍塌的问题，采用的手段是向材料中添加硅微粉材料抑制和抵消在气凝胶材料在高温下收缩和坍塌的问题。
进一步地，发明人通过对绝热层中的填料进行了改进和优化，合成和使用了由二氧化硅与氧化铝复合的二氧化硅/氧化铝复合气凝胶，复合气凝胶中的二氧化硅部分提供优秀的隔热能力，氧化铝部分提供优秀的耐温性能。氧化铝与二氧化硅分子结合，微观上可以抑制和降低二氧化硅分子在高温情况下的收缩、融化和晶型变化，宏观情况下减少绝热层(气凝胶毡)的掉粉情况，使得填料在高温情况下仍有隔热性能，以及以维持比较好的物理化学性能，满足使用要求。
进一步地，发明人通过对二氧化硅气凝胶做了改性和优化，改进了二氧化硅气凝胶材料的内部结构，将耐火性能更好但隔热性能略差的铝氧化物/铝盐材料与二氧化硅气凝胶结合，形成外壳是铝氧化物/铝盐而内核是二氧化硅气凝胶的复合二氧化硅气凝胶颗粒，或者形成外壳是二氧化硅气凝胶而内核是铝氧化物/铝盐的复合二氧化硅气凝胶颗粒。这样能够使得二氧 化硅气凝胶在高温情况下保持稳定，同时复合的颗粒具有较好的隔热性能，还可以维持比较好的物理化学性能，将其应用于绝热层可以满足防排烟通风管道的使用要求。
进一步的，发明人通过对二氧化硅气凝胶进行了稀土掺杂，具体的，由于稀土的掺杂可提高二氧化硅气凝胶的使用温度，扩展气凝胶在高温极端条件下应用，能控制气凝胶的密度、微观结构，进一步通过控制其中阴离子的含量，从而控制气凝胶的导热系数及其高温下的性能。可以掺杂的稀土元素包括钇、钪、钕和镱。
本技术方案解决了气凝胶无法达到防排烟风管耐温防火要求的问题，同时使绝热层具备良好的保温、消声吸音、防潮、漏风量小、使用寿命长、性价比合理等特点。发明人还发现虽然二氧化硅气凝胶的隔热性能非常好，但是其耐高温性能存在一定程度的缺陷，传统二氧化硅气凝胶在超过600℃开始融化，在800℃以上纳米孔道开始坍塌，在温度高于1000℃场合已基本失去保温效果，无法满足防排烟风管标准的要求。
本技术方案还可以解决现有技术中防排烟风管使用的隔热材料会出现吸水导致隔热结构坍塌、寿命短，同时由于导热系数高的原因导致占用空间较大的问题。在实际中火场风管在局部受热的情况下，还会出现风管结构变化坍塌、风管出现缺陷，导致管内风压变化、漏风，也会使得风管排风性能下降。
实施例14
本发明还提供一种防排烟耐火通风管道，所述防排烟耐火通风管道包括金属管道，金属管道内壁和/或外壁设置有热屏蔽层，热屏蔽层包括高温膨胀层和绝热层，还包括导热层、热反射层中的至少一种，所述绝热层采用上述的保温隔热材料或保温隔热复合材料。
根据本发明的一种实施方式，所述高温膨胀层包括高温发泡剂、多功能碳颗粒、稳定剂。高温发泡剂的发泡温度大于500℃，高温发泡剂是碳化硅粉末或颗粒。多功能碳颗粒可以是石墨、石墨烯。稳定剂是二氧化锰。高温膨胀层的厚度是1-5mm，膨胀后的厚度是20-100mm。一种优选的方案是还包括气凝胶颗粒，以提升高温膨胀层的隔热性能。气凝胶颗粒的添加的质量比例是3-5％。高温膨胀层还可以包含减水剂，减水剂为三聚磷酸钠或六偏磷酸钠。
研究发现，高温膨胀层在遇到高温时候碳化硅会膨胀发泡，高温膨胀层的厚度增加、导热率降低，同时内部添加的多功能碳颗粒在高温情况下兼具遮光剂的作用，减少高温情况下的热辐射。保护防排烟风管在高温情况下的结构稳定。多功能碳颗粒在高温膨胀层未发泡情况下(500℃以下)，由于还处于紧密压合状态，其具有比较好的导热功能，可以快速分散热量，降低局部过热的情况。当温度超过500℃以上时，通过导热分散也无法使得整体温度低于 排烟风管可耐受的温度时候，高温膨胀层膨胀发泡，其中的多功能碳颗粒由于被分散不在紧密连接导热性能消失，高温膨胀层由导热功能变为具有高温隔热性能的功能层。同时这些多功能碳颗粒在这种状况下，具有对红外线的吸收作用，起到了遮光剂的作用，进一步提高了高温状态下的隔热性能。
实施例15
在本发明所涉及的一个技术方案中，提供一种具有可用于快速连接固定结构的防排烟风管，风管通过风管单元拼接而成。
其中，每个风管单元的主体结构如图7和图8所示，包括金属主体框架、与框架内壁贴合的内壁热屏蔽层，与框架外壁贴合的外壁热屏蔽层，以及外壁热屏蔽层外侧相贴合的耐火密封胶。其中，所述内壁热屏蔽层、金属主体框架、外壁热屏蔽层、外侧耐火密封胶依次覆盖连接，连接方式可以为铆钉固定、粘连等常见的物理或化学连接方法。内壁热屏蔽层与外壁热屏蔽层可由绝热层、导热层、反射层中的单层或多层构成。此外，为使风管单元间能够紧密相连，实现密闭、隔热、防止热桥的功能，每个风管单元的两端分别设有延伸层与接收区域。
优选的，金属主体框架为彩钢板。
优选的，金属主体框架表面涂覆有抗菌涂层。
其中延伸层是指在一个风管单元的一端，沿平行于管壁方向从主体结构向外延伸的结构层。接收区域是指在风管单元上延伸层的另一端，为与另一个风管单元延伸层相连接所预留的区域，当两个风管单元相连接时，应为有延伸层的一端与有接收区域的一端相连接，连接后，两个风管单元在连接处可以紧密贴合，并在连接处通过连接组件固定。视延伸层的结构，在有接收区域的一端，风管单元的结构可以根据延伸层的结构进行单层或多层的延伸，以便于在风管单元间连接时可与延伸层贴合，该部分在接收端进行延伸的结构，定义为延伸接收层。
优选的，有两个待连接的风管单元，两个风管的结构相同，结构均包括风管单元主体、延伸层与接收区域，不包括延伸接收层。其中风管单元主体由金属管道、金属管道内壁热屏蔽层和金属管道外壁热屏蔽层构成，延伸层由外壁热屏蔽层沿平行于管壁方向进行向外延伸构成，延伸层沿平行于管壁方向的延伸长度与接收区域沿平行于管壁方向的预留宽度相同。
连接方式为：一个风管单元有延伸层的一端与另一个风管单元有接收区域的一端相连接，且两个风管单元的金属管道相接触，所延伸出的外壁热屏蔽层相接触，一个风管单元有延伸 层的一端所延伸出的外壁热屏蔽层，覆盖另一个风管单元有接收区域的一端的金属管道。连接后，两个风管单元贴合紧密，并通过连接组件固定。
优选的，上述连接组件包括：金属或其他耐高温材料制成的环绕式固定箍、螺栓、螺母。其中环绕式固定箍还包括限位孔，环绕式固定箍的宽度不小于风管延伸出的外壁热屏蔽层及的长度。
两个风管单元连接后的固定方式可以为：环绕式固定箍覆盖住两个风管单元金属管道与热屏蔽层连接的缝隙，螺栓穿过相应的限位孔，并用螺母旋紧固定。
风管可以是矩形的，风管长边边长b≤500mm，支吊架间距d≤2800mm；500mm≤风管长边边长b≤1000mm，支吊架间距d≤2400mm；1000mm≤风管长边边长b≤2000mm，支吊架间距d≤1400。
矩形风管尺寸可以是120mm、160mm、200mm、250mm、320mm、400mm、500mm、630mm、800mm、1000mm、1250mm、1600mm、2000mm、2500mm、3000mm、3500mm、4000mm。
优选的，两个待连接的风管单元在两端分别设有用于连接的角钢法兰结构，法兰由金属或其他耐高温材料制成，当两个风管单元连接后，位于两个风管单元连接缝两侧的两个角钢法兰结构可以紧密贴合，并通过连接组件固定。
优选的，上述连接组件包括：金属或其他耐高温材料制成的多个螺栓及螺母。连接方式为螺母穿过相应的角钢法兰上的限位孔，并通过螺栓固定锁紧。
实施例16
常规防排烟风管为了实现隔温、耐高温的性能，通常使用更厚的隔温材料，更高等级的耐火材料，阻断热量传递，从而达到隔温、耐高温的要求。发明人发现，防排烟风管的在紧急情况下，往往是局部受到高温影响，从而影响到其结构稳定性。防排烟的其余大部分位置，并没有达到设计极限而出现性能问题。因此发明人认为，可以使用导热而隔热、耐温的方法，将局部的高温扩散至防排烟风管其余的位置，降低局部的高温从而使得防排烟风管可以承受更高的温度。
在本发明所涉及的一个技术方案中，提供一种防排烟风管，防排烟风管包括金属管道100，金属管道100内壁和/或外壁设置有热屏蔽层200，热屏蔽层200包括绝热层210、导热层220、热反射层230的至少一种。绝热层可以使用上述保温隔热材料或上述保温隔热复合材料。
导热层220可以是金属导热板，如铜、铝等高导热性能的金属材料；还可以是导热金属结 构，如中空的导热夹层；还可以是设置有热管的装置的导热层220。
其中导热层220、热反射层230、绝热层210依次叠加构成热屏蔽层200。另外一种布置方式是热反射层230、导热层220、绝热层210依次叠加构成热屏蔽层200。绝热层210与金属管道100内壁和/或外壁贴合。
一种防排烟风管包括前风管140和后风管150，前风管140一端可拆卸连接有后风管150。
进一步地，防排烟风管还包括安装座160、定位杆161和定位筒162，安装座160对称设于前风管140和后风管150的侧面，所述定位杆161和定位筒162对应设于两侧安装座160的相对侧面，且定位杆161和定位筒162滑动配合，如图8所示。
进一步地，前风管和后风管之间设有第一连接组件和第二连接组件；第一连接组件包括限位孔、导孔、限位杆和螺帽，所述限位孔贯穿竖槽的上下两端，所述导孔贯穿竖方杆的上下两端，且导孔与限位孔对应，所述限位杆与导孔对应配合，所述螺帽螺纹连接在限位杆的顶端。
实施例17
常规防排烟风管为了实现隔温、耐高温的性能，通常使用更厚的隔温材料，更高等级的耐火材料，阻断热量传递，从而达到隔温、耐高温的要求。发明人发现，防排烟风管的在紧急情况下，往往是局部受到高温影响，从而影响到其结构稳定性。防排烟的其余大部分位置，并没有达到设计极限而出现性能问题。因此发明人认为，可以使用导热而隔热、耐温的方法，将局部的高温扩散至防排烟风管其余的位置，降低局部的高温从而使得防排烟风管可以承受更高的温度。
在本发明所涉及的一个技术方案中，提供一种防排烟风管，防排烟风管包括金属管道，金属管道内壁和/或外壁设置有热屏蔽层，热屏蔽层包括绝热层、导热层、热反射层的至少一种。绝热层可以使用上述保温隔热材料或上述保温隔热复合材料。
导热层可以是金属导热板，如铜、铝等高导热性能的金属材料；还可以是导热金属结构，如中空的导热夹层；还可以是设置有热管的装置的导热层。
其中导热层、热反射层、绝热层依次叠加构成热屏蔽层。另外一种布置方式是热反射层、导热层、绝热层依次叠加构成热屏蔽层。绝热层与金属管道内壁和/或外壁贴合。
导热层的形式包括硅胶散热膜、石墨散热膜、金属导热板、热管式导热板。金属导热板的材料可以是铜板、铝板。导热层的形式还可以是具有导热结构的通道，如双层中空金属导热板。导热层的在800℃情况下的导热系数范围是20W/m·K-50W/m·K。
在防排烟风管设置导热层可以强化防排烟风管的导热、散热性能，防止局部高温，可以避免内部的二氧化硅气凝胶颗粒在高温如600℃以上融化，使得绝热层在高温情况下仍能保维持结构稳定，满足防排烟风管的使用要求。
发明人还认为，可以在防排烟风管内部设置吸热层的方式降低局部高温，从而使得防排烟风管可以承受更高的温度。
在本发明所涉及的一个技术方案中，提供一种防排烟风管，防排烟风管包括金属管道，金属管道内壁和/或外壁设置有热屏蔽层，热屏蔽层包括绝热层，绝热层可以使用上述保温隔热材料或上述保温隔热复合材料，热屏蔽层还可以包括导热层、热反射层、吸热层的至少一种。
一种优选的方式是导热层、热反射层、吸热层、绝热层依次叠加构成热屏蔽层。其中导热层、热反射层、吸热层、绝热层依次叠加构成热屏蔽层。另外一种布置方式是热反射层、吸热层、绝热层依次叠加构成热屏蔽层。绝热层与金属管道内壁和/或外壁贴合。
吸热层由储热材料构成，储热材料可以是相变材料、受热挥发材料等，还可以是预置的降温材料如预置水仓、预置二氧化碳仓等，在遇到高温时候可以释放装载的水、二氧化碳等降温载体，吸收热量。相变材料可以吸收热量并保持温度恒定，从而在局部有高温的情况下，吸收热量产生相变而温度不升高，进而保护绝热层的气凝胶结构不坍塌，使得绝热层维持隔热效果，从而使得整个热屏蔽层在高温下仍能保持隔温效果。
相变材料为融盐类，熔融盐包括碳酸盐、氯化盐、氟化盐。
在防排烟风管设置吸热层可以降低防排烟风管的温度，防止局部高温，可以避免内部的二氧化硅气凝胶颗粒在高温如600℃以上融化，使得气凝胶绝热达到使用要求。
绝热层、导热层、热反射层、吸热层通过粘合、热压的方式相互固定。热屏蔽层外部还可以使用玻纤布、铝箔层包裹，防止填料碎裂掉粉的现象发生。
本发明突破传统陶瓷力学性能差、易脆的特性，拥有良好的柔软性，同时还保留有SiO 2材料耐高温的特性。首先结合静电纺丝的特性，将高分子聚合物溶液与中性硅溶胶混合制备可纺溶胶；然后在一定的湿度和温度条件下，采用静电纺丝制备有机/无机杂化的纳米纤维膜；在空气气氛中，控制煅烧温度以去除纤维膜中的有机成分，获得SiO 2陶瓷纳米纤维膜；最后利用硅烷偶联剂对制备得的SiO 2陶瓷纳米纤维膜进行疏水改性。本发明采用已产品化的硅溶胶为原料，工艺简单、制备周期短、成型性好，实验表明，本发明制备的SiO 2陶瓷纳米纤维膜有陶瓷纤维构成三维的互穿网络结构，具有低导热系数，其纤维平均直径为200～350nm，陶瓷纤维 膜的厚度为0.102～0.1836mm，拉伸力学强度为0.51～4.145Mpa，导热系数为0.04141～0.07416W/mK。本发明的SiO 2陶瓷纳米纤维膜力学性能良好、质量轻、疏水性能好，有望应用于航天航空领域以及高温潮湿环境，实现高效隔热。
上述实施例仅为本发明的较佳实施例，不能被认为用于限定本发明的实施范围。凡依本发明申请范围所作的均等变化与改进等，均应仍归属于本发明的专利涵盖范围之内。

Claims (26)

  1. 一种保温隔热材料，其特征在于，所述保温隔热材料为一种膜状材料或毡状材料，是一种柔性材料；所述保温隔热材料中包括SiO 2陶瓷纳米纤维构成的三维的互穿网络结构，所述纤维的平均直径为200nm～350nm。
  2. 根据权利要求1所述的保温隔热材料，其特征在于，所述保温隔热材料具备下述性能中的至少一种：
    1)耐高温，可在800～1200℃下使用；
    2)密度(g/cm)介于0.08至0.20之间；
    3)导热系数为0.04～0.08W/mK；
    4)拉伸力学强度为0.5～4.5MPa；
  3. 根据权利要求1或2所述的保温隔热材料，其特征在于，所述保温隔热材料中还包括遮光剂；
    和/或，所述纤维为具有中空结构的纳米中空纤维。
  4. 根据权利要求3所述的保温隔热材料，其特征在于，所述保温隔热材料表面具有疏水功能基团。
  5. 根据权利要求3所述的保温隔热材料，其特征在于，膜状材料的厚度为0.5mm～5.0mm。
  6. 根据权利要求3所述的保温隔热材料，其特征在于，毡状材料的厚度为0.5cm～5cm。
  7. 一种权利要求1-6任一项所述保温隔热材料的制备方法，其特征在于，所述方法包括以下步骤：
    1)配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
    2)配制SiO 2前驱体可纺溶胶：将步骤1)中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；所述高分子聚合物溶液与硅溶胶的重量比为1:(1～6)；
    3)制备保温隔热材料：将步骤2)的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到所述保温隔热材料；
    优选地，所述方法还包括以下步骤：
    4)制备具有疏水性能的保温隔热材料：采用疏水改性剂对步骤3)中的保温隔热材料进行疏水改性处理，干燥，得到所述具有疏水性能的保温隔热材料。
  8. 根据权利要求7所述的保温隔热材料的制备方法，其特征在于，所述模板聚合物为PVA粉末；所述PVA粉末为1788型。
  9. 根据权利要求7所述的保温隔热材料的制备方法，其特征在于，所述高分子聚合物溶液 的质量分数为10％～12％。
  10. 根据权利要求7所述的保温隔热材料的制备方法，其特征在于，所述硅溶胶的pH值为8.5～9.0，浓度为2～4mol/L，质量分数为15～25％，密度为0.957g/cm 3。
  11. 根据权利要求7所述的保温隔热材料的制备方法，其特征在于，所述高分子聚合物溶液与所述硅溶胶的质量比例如可为1:1、1:2、1:3、1:4、1:5或1:6。
  12. 根据权利要求7所述的保温隔热材料的制备方法，其特征在于，静电纺丝的针头内径为0.50mm～0.60mm；所述静电纺丝的参数为：相对湿度25％～45％，挤出速度为0.9～1.5ml/h，电压为12～16kv，接收装置与喷丝口间的距离为8～10cm，纺丝时间为1h～4h，采用金属滚筒作为接收装置，滚筒转速为40～70r/min。
  13. 根据权利要求12所述的保温隔热材料的制备方法，其特征在于，所述针头是同轴套管针头，所述同轴套管针头包括内层针头和外层针头，所述内层针头套管在所述外层针头内，并保持同轴。
  14. 根据权利要求13所述的保温隔热材料的制备方法，其特征在于，所述内层针头流动高分子聚合物溶液，所述内层针头与所述外层针头间流动SiO 2前驱体可纺溶胶。
  15. 一种保温隔热复合材料，其特征在于，所述复合材料是权利要求1-6任一项所述保温隔热材料与二氧化硅气凝胶或稀土掺杂二氧化硅气凝胶的复合物。
  16. 根据权利要求15所述的保温隔热复合材料，其特征在于，所述复合材料是上述保温隔热材料与二氧化硅气凝胶的复合物，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述二氧化硅气凝胶作为填料；
    或者，所述复合材料是上述保温隔热材料与稀土掺杂二氧化硅气凝胶的复合物，复合物包括骨架与填料，所述保温隔热材料作为骨架，所述稀土掺杂二氧化硅气凝胶作为填料。
  17. 根据权利要求15或16所述的保温隔热复合材料，其特征在于，所述气凝胶中进一步包括硅微粉；
    和/或，所述气凝胶中进一步包括遮光剂。
  18. 根据权利要求17所述的保温隔热复合材料，其特征在于，所述遮光剂包括二氧化钛、炭黑、SiC、六钛酸钾、ZrO 2中的至少一种。
  19. 根据权利要求18所述的保温隔热复合材料，其特征在于，所述二氧化钛是锐钛矿型二氧化钛。
  20. 根据权利要求18所述的保温隔热复合材料，其特征在于，所述二氧化钛是氟掺杂或者 氮掺杂的二氧化钛纳米颗粒。
  21. 一种权利要求15-20任一项所述保温隔热复合材料的制备方法，其特征在于，所述方法包括以下步骤：
    S1.制备硅溶胶：将硅源、水、醇溶剂混合制备硅溶胶；
    S2.制备稀土硅溶胶：配置稀土化合物溶液，并将稀土化合物溶液与上述硅溶胶混合，得到稀土硅溶胶；
    S3.制备纤维预制件，包括以下步骤：
    S3-1.配制纺丝助剂：模板聚合物与水配制高分子聚合物溶液作为纺丝助剂；
    S3-2.配制SiO 2前驱体可纺溶胶：将步骤S3-1中高分子聚合物溶液与硅溶胶混合，得到SiO 2前驱体可纺溶胶；
    S3-3.制备纤维预制件：将步骤S3-2的SiO 2前驱体可纺溶胶通过静电纺丝制备得到膜状材料或毡状材料，去除静电后，煅烧，得到纤维预制件；
    S4.纤维预制件改性：采用疏水改性剂对步骤S3中的纤维预制件进行疏水改性处理，干燥，得到具有疏水性能的纤维预制件；
    S5.制备凝胶：向步骤S1的硅溶胶或步骤S2的稀土硅溶胶中加入凝胶催化剂后，将其浇筑至步骤S3的纤维预制件或步骤S4的具有疏水性能的改性纤维预制件中，静置，获得凝胶；
    S6.干燥：对步骤S5的凝胶进行干燥，得到所述保温隔热复合材料。
  22. 根据权利要求21所述的保温隔热复合材料的制备方法，其特征在于，所述稀土化合物溶液由稀土金属盐配置而成，所述稀土金属盐为钇金属盐、钪金属盐、La系金属盐的一种或其组合。
  23. 根据权利要求22所述的保温隔热复合材料的制备方法，其特征在于，所述La系金属盐为钕金属盐、镱金属盐。
  24. 根据权利要求22所述的保温隔热复合材料的制备方法，其特征在于，所述钇金属盐为Y(NO 3) 3·4H 2O。
  25. 权利要求1-6任一项所述保温隔热材料或权利要求15-20任一项所述保温隔热复合材料的应用，其特征在于，用于高温潮湿环境下的保温隔热。
  26. 一种防排烟风管，所述防排烟风管包括金属管道，金属管道的内壁和/或外壁设置有热屏蔽层，所述热屏蔽层包括绝热层，所述绝热层包括权利要求1-6任一项所述保温隔热材料或权利要求15-20任一项所述保温隔热复合材料。
    Figure PCTCN2022119048-appb-100001
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CN116289184A (zh) * 2023-03-22 2023-06-23 东华大学 柔性陶瓷纳米纤维絮片的制备方法及应用
CN116693306A (zh) * 2023-05-31 2023-09-05 江苏龙冶节能科技有限公司 一种耐高温反射材料及其制备方法与用途
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CN116693306A (zh) * 2023-05-31 2023-09-05 江苏龙冶节能科技有限公司 一种耐高温反射材料及其制备方法与用途
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CN117385485B (zh) * 2023-12-07 2024-02-23 天津包钢稀土研究院有限责任公司 稀土基宽光谱被动降温中空隔热纤维及其制备方法和应用

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