CN110862258B - Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof - Google Patents

Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof Download PDF

Info

Publication number
CN110862258B
CN110862258B CN201911289402.7A CN201911289402A CN110862258B CN 110862258 B CN110862258 B CN 110862258B CN 201911289402 A CN201911289402 A CN 201911289402A CN 110862258 B CN110862258 B CN 110862258B
Authority
CN
China
Prior art keywords
carbon aerogel
silicon dioxide
porous
porous silicon
composite material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201911289402.7A
Other languages
Chinese (zh)
Other versions
CN110862258A (en
Inventor
艾兵
张世超
孙现凯
孙浩然
陈玉峰
胡利明
方凯
闫达琛
陶柳实
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
China Building Materials Academy CBMA
Original Assignee
China Building Materials Academy CBMA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by China Building Materials Academy CBMA filed Critical China Building Materials Academy CBMA
Priority to CN201911289402.7A priority Critical patent/CN110862258B/en
Publication of CN110862258A publication Critical patent/CN110862258A/en
Application granted granted Critical
Publication of CN110862258B publication Critical patent/CN110862258B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/14—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silica
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6562—Heating rate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
    • C04B2235/6565—Cooling rate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/77—Density
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C04B2235/9607—Thermal properties, e.g. thermal expansion coefficient

Abstract

The invention discloses a load-bearing carbon aerogel-porous silicon dioxide composite material and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, preparing block porous silicon dioxide by a microwave foaming method, then taking the block porous silicon dioxide as a carrier, adding the block porous silicon dioxide into a carbon aerogel precursor solution in the process of preparing the carbon aerogel, carrying out solvent replacement after gelation, supporting a skeleton of the block porous silicon dioxide material inside the carbon aerogel material after supercritical drying and carbonization, and uniformly filling carbon aerogel particles in pores of the block porous silicon dioxide material. The invention effectively improves the mechanical property of the carbon aerogel, forms a load-bearing carbon aerogel-porous silicon dioxide composite material, and can be used in the fields of heat insulation, catalysis, adsorption materials and the like.

Description

Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof
Technical Field
The invention relates to the field of carbon aerogel composite materials, in particular to a load-bearing carbon aerogel-porous silicon dioxide composite material and a preparation method thereof.
Background
Aerogel is the least dense solid material in the world at presentThe material is formed by aggregating and crosslinking countless nano particles and has a continuous three-dimensional nano porous structure. The carbon aerogel is a porous nano structure with extremely high porosity and high specific surface area (500-1500 m)2A/g) and a low density (0.01 to 0.03 g/cm)3) And the structural specificity enables the aerogel material to have excellent optical, electrical, thermal and other performances, so that the aerogel material has good application prospects in the fields of sound insulation, heat insulation, supercapacitors, catalysis and the like. However, most aerogel materials have low strength, poor toughness, and unstable structure, which greatly limits their applications. At present, two ways are known to improve the mechanical properties of aerogel materials, the first way is to control the preparation process of aerogel, regulate and control the internal structure of the carbon aerogel material, and increase the density of carbon aerogel, but this method can directly cause the density increase and the structure densification of aerogel, and the excellent properties of various optical, electrical and thermal properties are reduced; the second method is to add a reinforcing phase into the aerogel material to form a composite material, for example, in the literature, an inorganic fiber material, such as zirconia fiber, quartz fiber, mullite fiber, etc., is compounded with the aerogel to form an aerogel-fiber composite material having a certain compressive strength, but the composite material still has a certain compression deformation under the pressure, and the original structure of the aerogel cannot be maintained.
The massive porous silicon dioxide is a rigid porous structure material, has large internal surface area, large pore diameter range, high chemical stability, corrosion resistance and flame retardancy, and can be used in different fields of catalysis, adsorption carriers, heat insulation and the like.
Disclosure of Invention
In view of the above, the main objective of the present invention is to provide a load-bearing carbon aerogel-porous silica composite material and a preparation method thereof, in which a carbon aerogel and a block-shaped porous silica are compounded, so that the carbon aerogel is filled in pores of the block-shaped porous silica, and a porous frame structure of the block-shaped porous silica plays a role of a support for the carbon aerogel material, so as to solve the problem of shrinkage deformation of the carbon aerogel under the action of pressure.
In order to achieve the above object, the present invention provides a method for preparing a supported carbon aerogel-porous silica composite material, comprising the following steps:
1) firstly, water glass and ethylene glycol are used as main raw materials, water is used as a solvent, and a massive silicon dioxide porous material is prepared by a microwave foaming method and HCl steam treatment;
2) preparing a carbon aerogel precursor solution by using resorcinol and formaldehyde as reactants, alkali metal carbonate as a catalyst and water as a solvent;
3) placing the massive silica porous material obtained in the step 1) into the carbon aerogel precursor solution prepared in the step 2), and then sequentially carrying out gel curing treatment, solvent replacement, supercritical drying and carbonization to form the carbon aerogel-porous silica composite material.
Further, in step 1), the preparation of the bulk porous silica material specifically comprises:
s1, adding 0.3-1 g of ethylene glycol aqueous solution with the concentration of 5-20 wt% into 25-55 mL of sodium water glass with the concentration of 30-40 wt%, and fully and uniformly stirring to obtain a uniform solution; the water glass is sodium water glass or potassium water glass;
s2, pouring the solution obtained in the step S1 into a crucible, putting the crucible into a microwave oven, carrying out microwave heating for 3-6 min, taking out, cooling, and carrying out microwave heating again for 3-5 min;
s3, taking out the intermediate product obtained in the step S2, putting the intermediate product into a small beaker, putting the small beaker into a large beaker, dripping 2-4 mL of concentrated hydrochloric acid with the concentration of 36-40 wt% into the gap between the two beakers, sealing the small beaker by using a preservative film, putting the small beaker into a drying oven preheated to 90-100 ℃ in advance, preserving the temperature for 2 hours, taking out the product, repeatedly washing the product for 3-5 times by using distilled water, and drying the product to obtain the massive silica porous material.
Further, in step 2), the preparation of the carbon aerogel precursor solution specifically includes:
uniformly mixing resorcinol, formaldehyde, water and alkali metal carbonate according to a proportion to obtain a carbon aerogel precursor solution; wherein the molar ratio of the resorcinol to the formaldehyde is 1: 1.5-1: 2.5, the molar ratio of the alkali metal carbonate to the resorcinol is 1 (50-2000), and the molar ratio of the water to the resorcinol is (60-300): 1; the alkali metal carbonate is sodium carbonate or potassium carbonate.
Further, step 3) specifically comprises: placing the blocky silicon dioxide porous material obtained in the step 1) into the carbon aerogel precursor solution prepared in the step 2), preserving the heat for more than 48h at the temperature of 25-100 ℃ to obtain wet gel, performing solvent replacement on the wet gel for 3-5 times by using a low-surface-tension solvent absolute ethyl alcohol or a 30-40% (v/v) formaldehyde solution to avoid severe shrinkage in the drying process, removing the solvent through supercritical drying, and performing carbonization treatment to obtain the carbon aerogel-porous silicon dioxide composite material.
Further wherein the solvent displacement step is: fully soaking the wet gel in absolute ethyl alcohol at the soaking temperature of 30-60 ℃ for more than 12 hours, and repeating the step for 3-5 times.
Further, the supercritical drying specifically comprises: putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluid to make CO in high-pressure kettle2The supercritical state (the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38MPa), the pressure is maintained for 1-3 h until no ethanol flows out of the separation kettle, the pressure maintaining is stopped, a pressure release valve is opened to recover CO in the kettle2And when the pressure in the kettle is 0, taking out the dried aerogel.
Further, the parameters in which the xerogel is carbonized are set as follows: heating to 250 ℃ at the speed of 2-5 ℃/min, preserving heat for 3-4 h, heating to 1050 ℃ at the speed of 2-4 ℃/min, preserving heat for 4h, cooling to 650 ℃ at the speed of 2-4 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel-porous silicon dioxide composite material.
In order to achieve the above object, the present invention further provides a supported carbon aerogel-porous silica composite material, which comprises a carbon aerogel material and a bulk porous silica material supported inside the carbon aerogel material.
Further wherein the particles of the carbon aerogel material are uniformly filled in the pores of the bulk porous silica material.
Further, the density of the carbon aerogel-porous silica composite material is 0.062-0.071 g/cm-3The thermal conductivity coefficient is 0.025-0.034W/m.k, and the compressive strength is: 0.8 to 1.52 MPa.
The first key technology of the invention is to compound the carbon aerogel and the massive porous silicon dioxide. In the process of preparing the carbon aerogel material, the massive porous silicon dioxide material is put into the carbon aerogel precursor solution and is solidified with the precursor solution to form gel, the gel only wraps the massive porous silicon dioxide and is filled in the pores of the porous silicon dioxide material, and the carbon aerogel-silicon dioxide composite material is formed through further supercritical drying and carbonization. The second key technology of the invention is to solve the problem that the carbon aerogel material is extruded and deformed under the action of pressure. The massive porous silica is a rigid porous material, and the carbon aerogel material is filled in the pores of the porous silica, so that when external pressure is applied, the massive porous silica material can bear the external pressure, plays a role of framework support for the carbon aerogel, prevents the carbon aerogel material from shrinking under the action of the pressure, and maintains the high specific surface area and the high porosity of the carbon aerogel material.
The invention has the beneficial effects that: according to the preparation method, resorcinol and formaldehyde are used as raw materials, then the porous silicon dioxide is soaked in the carbon aerogel precursor solution by adopting a simple process flow, and the carbon aerogel-porous silicon dioxide composite material is prepared through the processes of gelling, drying and carbonizing; the carbon aerogel-porous silica composite material prepared by the invention has rigidity, the porous silica can be used as a framework of the aerogel to support the carbon aerogel, the compression resistance of the carbon aerogel material can be obviously improved, the carbon aerogel material can not be extruded and deformed under the action of pressure in a certain range, and the composite material has good application prospects in the fields of heat insulation, catalysis, adsorption materials and the like.
Detailed Description
The present invention will be further described with reference to the following examples, but the present invention is not limited to the following examples.
The following materials or reagents are commercially available unless otherwise specified.
Example 1
The embodiment provides a preparation method of a load-bearing carbon aerogel-porous silica composite material, which comprises the following steps:
1) preparing an ethylene glycol aqueous solution with the concentration of 5 wt%, adding 1g of the ethylene glycol aqueous solution into 25mL of sodium silicate with the concentration of 30 wt%, and fully and uniformly stirring to obtain a uniform solution;
2) pouring the obtained solution into a crucible, placing the crucible into a microwave oven, heating for 3min by microwave, taking out, cooling, and heating for 3min by microwave again. Taking out the intermediate product obtained before putting into a small beaker, putting the small beaker into a large beaker, dripping 2mL of concentrated hydrochloric acid with the concentration of 36 wt% into the gap between the two beakers, sealing the large beaker by using a preservative film, putting the large beaker into a drying oven preheated to 90 ℃ in advance, preserving heat for 2 hours, taking out the product, repeatedly washing the product for 3 times by using distilled water, and drying the product to obtain a massive silicon dioxide porous material;
3) uniformly mixing resorcinol, formaldehyde, water and sodium carbonate according to the following molar ratio to obtain a carbon aerogel precursor solution; wherein the molar ratio of resorcinol to formaldehyde is 1:2, the molar ratio of sodium carbonate to resorcinol is 1:50, and the molar ratio of water to resorcinol is 300: 1.
4) Placing the prepared massive silicon dioxide porous material in a carbon aerogel precursor solution, preserving heat for more than 48 hours at the temperature of 50 ℃ to obtain wet gel, fully soaking the wet gel in absolute ethyl alcohol at the temperature of 30 ℃, replacing the absolute ethyl alcohol once a day, and continuously operating for 3 days; then taking out the wet gel, putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluid to make CO in high-pressure kettle2The supercritical state (the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38MPa), the pressure is maintained for 1.5h until no ethanol flows out of the separation kettle, the pressure maintaining is stopped, a pressure release valve is opened to recover CO in the kettle2When the pressure in the kettle is 0, taking out the dried aerogel; will be provided withThe dry gel is carbonized, and the specific parameters are as follows: heating to 250 ℃ at the speed of 5 ℃/min, preserving heat for 4h, heating to 1050 ℃ at the speed of 2 ℃/min, preserving heat for 4h, cooling to 650 ℃ at the speed of 2 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel-porous silicon dioxide composite material.
The carbon aerogel-porous silica composite material has the density of 0.062g/cm through testing-3The thermal conductivity was 0.025W/m.k, and the compressive strength was 0.80 MPa.
Example 2
The embodiment provides a preparation method of a load-bearing carbon aerogel-porous silica composite material, which comprises the following steps:
1) preparing 15 wt% ethylene glycol aqueous solution, adding 0.3g of ethylene glycol aqueous solution into 55mL of 35 wt% sodium silicate, and fully and uniformly stirring to obtain uniform solution;
2) pouring the obtained solution into a crucible, putting the crucible into a microwave oven, heating for 3min by microwave, taking out, cooling, and heating for 3min by microwave again. Taking out the intermediate product obtained before putting into a small beaker, putting the small beaker into a large beaker, dripping 2mL of concentrated hydrochloric acid with the concentration of 40wt% into the gap between the two beakers, sealing the large beaker by using a preservative film, putting the large beaker into a drying oven preheated to 90 ℃ in advance, preserving the temperature for 2 hours, taking out the product, repeatedly washing the product for 4 times by using distilled water, and drying the product to obtain a massive silicon dioxide porous material;
3) uniformly mixing resorcinol, formaldehyde, water and potassium carbonate according to a molar ratio to obtain a carbon aerogel precursor solution; wherein the molar ratio of resorcinol to formaldehyde is 1:2, the molar ratio of potassium carbonate to resorcinol is 1:2000, and the molar ratio of water to resorcinol is 60: 1.
4) Placing the prepared massive silicon dioxide porous material in a carbon aerogel precursor solution, preserving heat for more than 48 hours at the temperature of 50 ℃ to obtain wet gel, fully soaking the wet gel in absolute ethyl alcohol at the temperature of 45 ℃, replacing the absolute ethyl alcohol once a day, and continuously operating for 4 days; then taking out the wet gel, putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluidFluid to make CO in the autoclave2The supercritical state (the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38MPa), the pressure is maintained for 1h until no ethanol flows out of the separation kettle, the pressure maintaining is stopped, the pressure release valve is opened to recover CO in the kettle2When the pressure in the kettle is 0, taking out the dried aerogel; carrying out carbonization treatment on the xerogel, wherein the specific parameters are as follows: heating to 250 ℃ at the speed of 2 ℃/min, preserving heat for 3h, heating to 1050 ℃ at the speed of 3 ℃/min, preserving heat for 4h, cooling to 650 ℃ at the speed of 2 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel-porous silicon dioxide composite material.
The carbon aerogel-porous silicon dioxide composite material has the density of 0.071g/cm through testing-3The thermal conductivity was 0.034W/m.k, and the compressive strength was 1.52 MPa.
Example 3
The embodiment provides a preparation method of a load-bearing carbon aerogel-porous silica composite material, which comprises the following steps:
1) preparing 20wt% ethylene glycol aqueous solution, taking 0.75g ethylene glycol aqueous solution, adding the ethylene glycol aqueous solution into 40mL sodium water glass with the concentration of 40%, and fully and uniformly stirring to obtain uniform solution;
2) pouring the obtained solution into a crucible, putting the crucible into a microwave oven, heating for 6min by microwave, taking out, cooling, and heating for 5min by microwave again. And taking out the intermediate product obtained before putting into a small beaker, putting the small beaker into a large beaker, dripping 4mL of concentrated hydrochloric acid with the concentration of 37 wt% into the gap between the two beakers, sealing the large beaker by using a preservative film, putting into a baking oven preheated to 100 ℃ in advance, preserving heat for 2 hours, taking out the product, repeatedly washing for 5 times by using distilled water, and drying to obtain the massive silicon dioxide porous material.
3) Uniformly mixing resorcinol, formaldehyde, water and potassium carbonate according to the following molar ratio to obtain a carbon aerogel precursor solution; wherein the molar ratio of resorcinol to formaldehyde is 1:2, the molar ratio of potassium carbonate to resorcinol is 500:1, and the molar ratio of water to resorcinol is 200: 1.
4) Placing the prepared massive silicon dioxide porous material in front of carbon aerogelKeeping the temperature of the solution at 100 ℃ for more than 48h to obtain wet gel, soaking the wet gel in absolute ethyl alcohol at 60 ℃, replacing the absolute ethyl alcohol once a day, and continuously operating for 5 days; then taking out the wet gel, putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluid to make CO in high-pressure kettle2The supercritical state (the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38MPa), the pressure is maintained for 2 hours until no ethanol flows out of the separation kettle, the pressure maintaining is stopped, the pressure release valve is opened to recover CO in the kettle2When the pressure in the kettle is 0, taking out the dried aerogel; carrying out carbonization treatment on the xerogel, wherein the specific parameters are as follows: heating to 250 ℃ at a speed of 4 ℃/min, preserving heat for 3h, heating to 1050 ℃ at a speed of 4 ℃/min, preserving heat for 4h, cooling to 650 ℃ at a speed of 4 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel-porous silicon dioxide composite material.
The carbon aerogel-porous silicon dioxide composite material has the density of 0.066g/cm through testing-3The thermal conductivity coefficient is 0.027W/m.k, and the compressive strength is: 0.95 MPa.
Example 4
The embodiment provides a preparation method of a load-bearing carbon aerogel-porous silica composite material, which comprises the following steps:
1) preparing an ethylene glycol aqueous solution with the concentration of 18 wt%, taking 0.5g of the ethylene glycol aqueous solution, adding the ethylene glycol aqueous solution into 30mL of 35 wt% potassium water glass, and fully and uniformly stirring to obtain a uniform solution;
2) pouring the obtained solution into a crucible, putting the crucible into a microwave oven, heating for 6min by microwave, taking out, cooling, and heating for 3min by microwave again. And taking out the intermediate product obtained before putting into a small beaker, putting the small beaker into a large beaker, dripping 4mL of concentrated hydrochloric acid with the concentration of 38 wt% into the gap between the two beakers, sealing the large beaker by using a preservative film, putting into a baking oven preheated to 100 ℃ in advance, preserving heat for 2 hours, taking out the product, repeatedly washing with distilled water for 4 times, and drying to obtain the massive silicon dioxide porous material.
3) Uniformly mixing resorcinol, formaldehyde, water and sodium carbonate according to the following molar ratio to obtain a carbon aerogel precursor solution; wherein the molar ratio of the resorcinol to the formaldehyde is 1:2, the molar ratio of the sodium carbonate to the resorcinol is 1:1200, the molar ratio of the water to the resorcinol is 220:1, and the carbon aerogel precursor solution is obtained after mixing and fully stirring uniformly.
4) Placing the prepared massive silicon dioxide porous material in a carbon aerogel precursor solution, preserving heat for more than 48 hours at the temperature of 25 ℃ to obtain wet gel, soaking the wet gel in absolute ethyl alcohol at the temperature of 50 ℃, replacing the absolute ethyl alcohol once a day, and continuously operating for 3 days; then taking out the wet gel, putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluid to make CO in high-pressure kettle2The supercritical state (the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38MPa), the pressure is maintained for 3 hours until no ethanol flows out of the separation kettle, the pressure maintaining is stopped, the pressure release valve is opened to recover CO in the kettle2When the pressure in the kettle is 0, taking out the dried aerogel; carrying out carbonization treatment on the xerogel, wherein the specific parameters are as follows: heating to 250 ℃ at the speed of 2 ℃/min, preserving heat for 3h, heating to 1050 ℃ at the speed of 3 ℃/min, preserving heat for 4h, cooling to 650 ℃ at the speed of 3 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel-porous silicon dioxide composite material.
The carbon aerogel-porous silicon dioxide composite material has the density of 0.068g/cm through testing-3The thermal conductivity coefficient is 0.031W/m.k, and the compressive strength is: 1.32 MPa.
In summary, the density of the carbon aerogel-porous silica composite material prepared in the above embodiments 1 to 4 is 0.062 to 0.071g/cm-3The thermal conductivity coefficient is 0.025-0.034W/m.k, and the compressive strength is: 0.80-1.52 MPa, and can solve the problem that the carbon aerogel generates shrinkage deformation under the action of pressure.
According to the preparation method, resorcinol and formaldehyde are used as raw materials, then the porous silicon dioxide is soaked in the carbon aerogel precursor solution by adopting a simple process flow, and the carbon aerogel-porous silicon dioxide composite material is prepared through the processes of gelling, drying and carbonizing; the carbon aerogel-porous silica composite material prepared by the invention has rigidity, the porous silica can be used as a framework of the aerogel to support the carbon aerogel, the compression resistance of the carbon aerogel material can be obviously improved, the carbon aerogel material can not be extruded and deformed under the action of pressure in a certain range, and the composite material has good application prospects in the fields of heat insulation, catalysis, adsorption materials and the like.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims (6)

1. The preparation method of the load-bearing carbon aerogel-porous silica composite material is characterized by comprising the following steps of:
1) firstly, preparing a massive silicon dioxide porous material by using sodium water glass or potassium water glass and ethylene glycol as main raw materials and water as a solvent through a microwave foaming method and HCl steam treatment;
2) preparing a carbon aerogel precursor solution by using resorcinol and formaldehyde as reactants, alkali metal carbonate as a catalyst and water as a solvent;
3) placing the massive silica porous material obtained in the step 1) into the carbon aerogel precursor solution prepared in the step 2), preserving heat for more than 48 hours at the temperature of 25-100 ℃ to obtain wet gel, fully soaking the wet gel into a low surface tension solvent at the temperature of 30-60 ℃ for more than 12 hours, repeating the step for 3-5 times, removing the solvent in the wet gel through supercritical drying to obtain dry gel, and carbonizing the dry gel to obtain the carbon aerogel-porous silica composite material; the low surface tension solvent is absolute ethyl alcohol;
in the step 1), the preparation of the massive silica porous material specifically comprises the following steps:
s1, adding 0.3-1 g of ethylene glycol aqueous solution with the concentration of 5-20 wt% into 25-55 mL of water glass with the concentration of 30-40 wt%, and fully and uniformly stirring to obtain a uniform solution; the water glass is sodium water glass or potassium water glass;
s2, pouring the solution obtained in the step S1 into a crucible, putting the crucible into a microwave oven, carrying out microwave heating for 3-6 min, taking out, cooling, and carrying out microwave heating again for 3-5 min;
s3, taking out the intermediate product obtained in the step S2, placing the intermediate product into a small beaker, placing the small beaker into a large beaker, dripping 2-4 mL of hydrochloric acid with the concentration of 36-40 wt% into the gap between the two beakers, sealing the small beaker by using a preservative film, placing the small beaker into a drying oven preheated to 90-100 ℃ in advance, preserving the temperature for 2 hours, taking out the product, repeatedly washing the product for 3-5 times by using distilled water, and drying the product to obtain the massive silica porous material.
2. The method according to claim 1, wherein the step 2) of preparing the carbon aerogel precursor solution specifically comprises:
uniformly mixing resorcinol, formaldehyde, water and alkali metal carbonate according to a proportion to obtain a carbon aerogel precursor solution; wherein the molar ratio of the resorcinol to the formaldehyde is 1: 1.5-1: 2.5, the molar ratio of the alkali metal carbonate to the resorcinol is 1 (50-2000), and the molar ratio of the water to the resorcinol is (60-300): 1; the alkali metal carbonate is sodium carbonate or potassium carbonate.
3. The preparation method according to claim 1, wherein the supercritical drying specifically comprises: putting the wet gel into an autoclave of supercritical drying equipment, and introducing CO2Supercritical fluid to make CO in high-pressure kettle2Maintaining the pressure for 1-3 h until no ethanol flows out of the separation kettle, stopping maintaining the pressure, opening a pressure release valve to recover CO in the kettle2When the pressure in the kettle is 0, taking out the dried aerogel; the CO is2The supercritical state of (A) is: the temperature is higher than 31.1 ℃, and the pressure is higher than 7.38 MPa.
4. The production method according to claim 1, wherein the parameters for the carbonization treatment of the xerogel are set as follows: heating to 250 ℃ at the speed of 2-5 ℃/min, preserving heat for 3-4 h, heating to 1050 ℃ at the speed of 2-4 ℃/min, preserving heat for 4h, cooling to 650 ℃ at the speed of 2-4 ℃/min, and finally cooling to room temperature along with the furnace to obtain the carbon aerogel.
5. A supported carbon aerogel-porous silica composite prepared by the preparation method of any one of claims 1 to 4, which comprises a carbon aerogel material and a bulk porous silica material supported inside the carbon aerogel material; the density of the carbon aerogel-porous silicon dioxide composite material is 0.062-0.071 g/cm-3The thermal conductivity coefficient is 0.025-0.034W/m.k, and the compressive strength is: 0.80 to 1.52 MPa.
6. The supported carbon aerogel-porous silica composite of claim 5, wherein the particles of carbon aerogel material are uniformly filled in the pores of the bulk porous silica material.
CN201911289402.7A 2019-12-13 2019-12-13 Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof Active CN110862258B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911289402.7A CN110862258B (en) 2019-12-13 2019-12-13 Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911289402.7A CN110862258B (en) 2019-12-13 2019-12-13 Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof

Publications (2)

Publication Number Publication Date
CN110862258A CN110862258A (en) 2020-03-06
CN110862258B true CN110862258B (en) 2022-04-22

Family

ID=69658869

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911289402.7A Active CN110862258B (en) 2019-12-13 2019-12-13 Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN110862258B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114574085B (en) * 2022-03-10 2023-02-10 山东沃丰新材料有限公司 Heat-insulation color aluminum plate and processing technology

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101633505A (en) * 2009-08-25 2010-01-27 郑文芝 SiO2 nanoscale porous material with aerogel property prepared by microwave reaction and preparation method thereof
CN103044057A (en) * 2013-01-14 2013-04-17 航天材料及工艺研究所 Carbon foam in-situ reinforced carbon aerogel high-temperature thermal insulation material and preparation method thereof
CN104355313A (en) * 2014-08-06 2015-02-18 泉州三欣新材料科技有限公司 Simple and easy preparation method for silicon dioxide hydrophobic porous materials

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6770584B2 (en) * 2002-08-16 2004-08-03 The Boeing Company Hybrid aerogel rigid ceramic fiber insulation and method of producing same
CN102557052A (en) * 2012-03-05 2012-07-11 中国科学院上海硅酸盐研究所 Method for rapidly preparing low-density silicon oxide aerogel
CN104129973B (en) * 2014-08-08 2017-02-15 苏州宏久航空防热材料科技有限公司 Preparation method of SiO2 aerogel-filled carbon aerogel

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101633505A (en) * 2009-08-25 2010-01-27 郑文芝 SiO2 nanoscale porous material with aerogel property prepared by microwave reaction and preparation method thereof
CN103044057A (en) * 2013-01-14 2013-04-17 航天材料及工艺研究所 Carbon foam in-situ reinforced carbon aerogel high-temperature thermal insulation material and preparation method thereof
CN104355313A (en) * 2014-08-06 2015-02-18 泉州三欣新材料科技有限公司 Simple and easy preparation method for silicon dioxide hydrophobic porous materials

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
水玻璃一步凝胶法制备SiO2气凝胶的酸性催化剂选择;欧传奇;《新疆化工》;20111231;第18-21页 *

Also Published As

Publication number Publication date
CN110862258A (en) 2020-03-06

Similar Documents

Publication Publication Date Title
CN101913835B (en) Foamed ceramic reinforcing fiber aerogel insulating material and preparation method thereof
CN108329046B (en) Preparation method of carbon aerogel heat insulation composite material
CN109251005B (en) Preparation method of reinforced silica aerogel material
CN101671158A (en) Silicon dioxide heat insulator and preparation method thereof
CN112592150B (en) Preparation method of alumina-silica aerogel heat-insulation composite material
CN103496706A (en) Preparation method of aerogel composite material
CN112047711A (en) Method for improving high-temperature heat-insulating property of nano porous heat-insulating material
CN108147835B (en) Method for preparing ceramic block with hierarchical pore structure by taking bacterial cellulose as biological template
CN1888302A (en) Process for producing nano porous flexible felt composite material and application
CN110862258B (en) Load-bearing carbon aerogel-porous silicon dioxide composite material and preparation method thereof
CN104478475A (en) High-temperature-resistant high-strength SiC clad carbon foam composite thermal insulating material and preparation method thereof
CN111040235A (en) Aerogel composite material and preparation method thereof
CN113816720A (en) PBO fiber product composite aerogel high-performance heat-insulating material and preparation method thereof
CN108609606B (en) Preparation method of carbon aerogel heat insulation material
CN108484097B (en) Preparation method of lignin-enhanced silicon dioxide aerogel felt
CN113003947A (en) Preparation method of silicon-based aerogel-foam material heat insulation composite material
CN109020470A (en) A kind of method that constant pressure and dry prepares aeroge complex heat-preservation felt
WO2017211227A1 (en) High-strength large dimension block-form aerographite, and manufacturing method and application thereof
CN115110311B (en) Preparation method of high-temperature-resistant alumina aerogel felt and alumina aerogel felt
CN115231897B (en) Method for preparing carbon fiber and carbon nanotube composite silicon aerogel based on freeze drying by taking water glass as silicon source
CN106592195B (en) A kind of aeroge fibrofelt composite material and preparation method
CN113860850B (en) Composite heat insulation pad and manufacturing process thereof
CN111847463B (en) Preparation method of silicon dioxide nano aerogel fiber
CN114409424A (en) Method for preparing low-density, high-strength and large-size carbon aerogel composite material by water-phase normal-pressure drying
CN109573980B (en) Method for preparing high-strength blocky porous carbon by pyrolysis-normal pressure carbonization

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant