CN116333368A - Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof - Google Patents

Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof Download PDF

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CN116333368A
CN116333368A CN202310627231.4A CN202310627231A CN116333368A CN 116333368 A CN116333368 A CN 116333368A CN 202310627231 A CN202310627231 A CN 202310627231A CN 116333368 A CN116333368 A CN 116333368A
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heat exchange
exchange material
membrane
conducting
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朱倩怡
高启君
李占龙
梁亮
刘玉润
刘富昌
孙慧欣
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Tianjin University of Technology
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Abstract

The invention relates to a heat-conducting particle filled type plastic heat exchange material and a preparation method and application thereof, wherein a porous membrane is used as a heat-conducting main body of the plastic heat exchange material, nano particles with high heat conductivity are filled in micro pore channels of the membrane by using a decompression filtering, ultrafiltration and microfiltration method, and mass transfer micro channels of the membrane are constructed into heat conducting channels, so that the heat-conducting particle filled type membrane material is obtained; the outer surface of the filling film is coated by a sol-gel method to prepare a compact layer capable of blocking cold and hot fluid cross-wall mass transfer, so that the filling type plastic heat exchange material is prepared. The preparation process is simple and controllable, and the obtained filling type plastic heat exchange material is uniform in form; on one hand, the high heat conducting performance and the constructed heat conducting micro-channel are utilized to improve the heat conducting performance of the plastic heat exchange material, and on the other hand, the nano-particles filled in the pore canal of the membrane can greatly block the permeation of cold and hot fluid across the wall, reduce the mechanical requirement of a compact layer and improve the comprehensive performance of the heat conducting particle filled plastic heat exchange material.

Description

Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof
Technical Field
The invention relates to the field of plastic heat exchangers, in particular to a heat-conducting particle filled type plastic heat exchange material with high heat conduction, a preparation method and application thereof.
Background
The heat exchanger is not only an important device for modern industrial production, but also one of energy-saving and emission-reducing (waste heat utilization) sharps for enterprises in high-energy-consumption industries such as petrifaction, steel, electric power and the like. The metal heat exchanger as the main stream has a plurality of problems of easy corrosion, easy scaling on the surface and the like in practical application. The plastic heat exchanger prepared from the high molecular polymer has the remarkable advantages of simple processing, low cost and light weight, and has great industrial application prospect because the problems of the metal heat exchanger can be well avoided. However, the plastic material has poor heat conduction performance, which is one of the key problems for limiting the popularization and application of the plastic heat exchanger.
The method for improving the heat conduction performance of the plastic is mainly two, namely, an intrinsic novel heat conduction material with a special structure is polymerized by a chemical method, and the method has the advantages of high difficulty, long period and high development cost; secondly, the filled heat-conducting composite polymer material is prepared by physical blending modification, and the method has simple process, low cost and wide application in the heat conduction field, and is a main method for improving the heat conduction performance of the polymer material at present. For filled heat-conducting composite polymer materials, the factors determining the heat-conducting property are the heat-conducting property of the material to be filled into the polymer matrix (filler for short) and the content of the filler in the composite material. When the filler is added in a small amount, the filler exists in a dispersed phase form in a polymer matrix, is wrapped by the polymer and cannot be lapped to form an effective heat conducting net chain. In order for the composite polymeric material to have an effective thermally conductive network chain within it, the filler must be added in an amount exceeding a certain critical value, often at the expense of the mechanical properties of the thermally conductive composite polymeric material.
The membrane separation technology is one of the most important means in the separation science at present, is widely applied to various fields of industrial production, and has great economic and social benefits. Currently, most separations used in membrane separation technology
Figure SMS_1
Is composed of
Figure SMS_2
The material is made of the material, has excellent corrosion resistance and mechanical strength, is internally porous and has high porosity. The hollow fiber polymer porous membrane has larger specific surface area in the same volume compared with a tubular membrane with larger outer diameter, and becomes the first membrane material used in the membrane separation technology. For the porous membrane, the heat conducting filler is hopefully filled into mass transfer micro-channels with high porosity of the porous membrane by the methods of decompression filtration, ultrafiltration, microfiltration and the like, so that the heat conducting property of the membrane is obviously improved, and meanwhile, the mechanical property of the membrane is not obviously reduced. The method solves the problem that the filler is limited in addition amount due to poor dispersibility of the filler in a polymer matrix in a melt blending method and a solution blending method, and also solves the problem that the mechanical property of the composite polymer material is obviously sacrificed when the addition amount of the filler is large.
Pei Xin (Pei Xin. 3D-BNNS/silicon modified epoxy resin high thermal conductivity composite material development [ D ] ]Harbin, university of Harbin, 2019) preparing a few-layer hexagonal boron nitride (BNNS) nanosheet with ultrahigh thermal conductivity by ultrasonic degradation, mixing the nanosheet with polyacrylic acid (PAA), and preparing the 3D-BNNS gas with a three-dimensional grid structureAnd (5) gel. And immersing the organic silicon modified epoxy resin capable of providing mechanical properties for the heat-conducting composite material into the 3D-BNNS aerogel by a vacuum impregnation method to prepare the 3D-BNNS/silicon modified epoxy resin high heat-conducting composite material. It was found that at a BNNS content of 10 wt%, the thermal conductivity of the composite material reached a maximum (1.68W. Multidot.m -1 ·K -1 ) However, BNNS is unevenly distributed in the aerogel, the porosity of the system is reduced, the pore diameter is reduced, the epoxy resin cannot be fully impregnated into the aerogel, and the mechanical property of the composite polymer material is reduced.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a preparation method of a heat-conducting particle filled plastic heat exchange material, wherein a porous membrane is used as a heat-conducting main body of the plastic heat exchange material, high-heat-conducting nano particles are filled in micro-pore channels of the membrane by using methods of decompression filtration, ultrafiltration and microfiltration, and mass transfer micro-channels of the membrane are constructed into heat-conducting micro-channels to obtain a filled membrane; on the outer surface of the filling film, a compact layer capable of blocking cold and hot fluid cross-wall mass transfer is coated and prepared by adopting a sol-gel method, so that the filling type plastic heat exchange material is prepared, on one hand, the high heat conduction performance of the heat conduction nano particles and the constructed heat conduction micro-channel are utilized, the heat conduction performance of the plastic heat exchange material is improved, and on the other hand, the heat conduction nano particles filled in the pore canal of the mask greatly block the penetration of the cold and hot fluid of the cross-film wall, the mechanical requirement of the compact layer to be prepared in the later stage is reduced, and the comprehensive performance of the heat conduction particle filling type plastic heat exchange material is improved.
The invention solves the technical problems by the following technical proposal:
a preparation method of a heat-conducting particle filled plastic heat exchange material comprises the following steps:
step 1) selecting a porous membrane:
a porous membrane is adopted as a heat conduction main body of the plastic heat exchange material;
step 2) preparation of a heat conducting particle filling type film material:
(1) placing the heat conduction nano particles in deionized water, stirring for 0.5-2.0 h at room temperature, and then performing ultrasonic treatment for 2.0-5.0 h to prepare filling liquid with the concentration of 1.0-5.0 wt%;
(2) filtering by taking filling liquid as filtrate and adopting a method of reduced pressure filtration, ultrafiltration or microfiltration for 10-60 min, and utilizing the interception characteristic of the membrane pore canal of the porous membrane to intercept nano particles in the filling liquid in the membrane pore canal of the porous membrane so as to realize the filling of the heat conduction nano particles in the filling liquid to the membrane pore canal;
(3) after filling, cleaning the inner cavity of the porous membrane for 0.2-1.0 h, and then drying in an oven at 65-75 ℃ for 4.0-8.0 h to dryness to prepare a heat-conducting particle filled membrane material;
step 3) preparation of a heat-conducting particle filled plastic heat exchange material:
(1) weighing a certain amount of polydimethylsiloxane as a precursor, dissolving the precursor in a solvent of normal hexane, magnetically stirring at room temperature for 0.5-2.0 h, adding heat-conducting nano particles, continuing to magnetically stir for 0.5-2.0 h, and then performing ultrasonic treatment for 2.0-5.0 h to ensure uniform particle dispersion, thereby obtaining a dispersion liquid with the concentration of polydimethylsiloxane of 5-30 wt% and the addition amount of the heat-conducting nano particles of 0.5-8.0 wt%;
(2) Slowly dripping ethyl orthosilicate and dibutyl tin dilaurate serving as a cross-linking agent and a catalyst into the dispersion liquid, and stirring for 0.5-2.0 h to be uniform to prepare a coating solution with the concentration of both ethyl orthosilicate and dibutyl tin dilaurate of 1.0-6.0 wt%;
(3) placing the heat conducting particle filled film material into the stirred coating solution, and coating for 10-60 min while stirring; and (3) placing the coated filled heat exchange material for 6-24 hours at room temperature, and placing the coated filled heat exchange material into an oven at 65-75 ℃ for curing for 6-24 hours to obtain the heat conduction particle filled plastic heat exchange material with the compact layer on the surface.
Moreover, the porous membrane described in step 1) includes a tubular membrane, a hollow fiber membrane, or a flat plate membrane.
The porous membrane has a porosity of 65% -85% and an average pore diameter of 0.01-0.70 [ mu ] m.
In addition, the porous membrane is composed of a supporting layer and a separating layer, and in order to improve the mechanical property of the plastic heat exchange material, the porous membrane material containing rib lines or woven fibers in the supporting layer is preferably selected; the separating layer material of the porous membrane is polyvinylidene fluoride, polysulfone, polyethersulfone, polyacrylonitrile, polyvinyl chloride, polypropylene or polytetrafluoroethylene; the reinforcement wire material is polyvinylidene fluoride, polytetrafluoroethylene, polyester or nylon, and the diameter of the reinforcement wire is 0.01-0.50 mm; the woven fiber material is selected from nylon, acrylic, polypropylene, terylene, polyvinyl chloride, vinylon, spandex or glass fiber, and the denier of the woven fiber material is 0.1-1.0 denier.
The heat conducting nano particles in the step 2) comprise metal, metal oxide, nitride and inorganic non-metal nano particles, wherein the inorganic non-metal nano particles comprise graphite, carbon black, carbon nano tubes, silicon carbide, aluminum oxide or graphene, and the particle size of the heat conducting nano particles is 15-100 nm.
Further, the step 2) includes a filling termination judging step, and the judging method includes a weighing method or a mass transfer flux measuring method, wherein the weighing method is as follows: weighing the filled porous membrane, and stopping filling when the mass is no longer increased; the mass transfer flux assay is: and measuring the mass transfer flux of the filled porous membrane, and stopping filling when the mass transfer flux is no longer reduced.
Furthermore, the dense layer preparation method described in step 3) is a sol-gel coating method.
The heat conducting nano particles in the step 3) comprise metal, metal oxide, nitride and inorganic non-metal nano particles, wherein the inorganic non-metal nano particles comprise graphite, carbon black, carbon nano tubes, silicon carbide, aluminum oxide or graphene, and the particle size of the heat conducting nano particles is 15-100 nm.
A heat-conducting particle filled plastic heat exchange material, wherein the heat conductivity coefficient of the heat-conducting particle filled plastic heat exchange material at room temperature is 0.5-5.5 W.m -1 ·K -1 The mechanical property of the steel is 500-1000 cN, which is characterized by breaking strength;
the preparation method of the heat-conducting particle filled plastic heat exchange material comprises the following steps:
step 1) selecting a porous membrane:
a porous membrane is adopted as a heat conduction main body of the plastic heat exchange material;
step 2) preparation of a heat conducting particle filling type film material:
(1) placing the heat conduction nano particles in deionized water, stirring for 0.5-2.0 h at room temperature, and then performing ultrasonic treatment for 2.0-5.0 h to prepare filling liquid with the concentration of 1.0-5.0 wt%;
(2) filtering by taking filling liquid as filtrate and adopting a method of reduced pressure filtration, ultrafiltration or microfiltration for 10-60 min, and utilizing the interception characteristic of the membrane pore canal of the porous membrane to intercept nano particles in the filling liquid in the membrane pore canal of the porous membrane so as to realize the filling of the heat conduction nano particles in the filling liquid to the membrane pore canal;
(3) after filling, cleaning the inner cavity of the porous membrane for 0.2-1.0 h, and then drying in an oven at 65-75 ℃ for 4.0-8.0 h to dryness to prepare a heat-conducting particle filled membrane material;
step 3) preparation of a heat-conducting particle filled plastic heat exchange material:
(1) weighing a certain amount of polydimethylsiloxane as a precursor, dissolving the precursor in a solvent of normal hexane, magnetically stirring at room temperature for 0.5-2.0 h, adding heat-conducting nano particles, continuing to magnetically stir for 0.5-2.0 h, and then performing ultrasonic treatment for 2.0-5.0 h to ensure uniform particle dispersion, thereby obtaining a dispersion liquid with the concentration of polydimethylsiloxane of 5-30 wt% and the addition amount of the heat-conducting nano particles of 0.5-8.0 wt%;
(2) Slowly dripping ethyl orthosilicate and dibutyl tin dilaurate serving as a cross-linking agent and a catalyst into the dispersion liquid, and stirring for 0.5-2.0 h to be uniform to prepare a coating solution with the concentration of both ethyl orthosilicate and dibutyl tin dilaurate of 1.0-6.0 wt%;
(3) placing the heat conducting particle filled film material into the stirred coating solution, and coating for 10-60 min while stirring; and (3) placing the coated filled heat exchange material for 6-24 hours at room temperature, and placing the coated filled heat exchange material into an oven at 65-75 ℃ for curing for 6-24 hours to obtain the heat conduction particle filled plastic heat exchange material with the compact layer on the surface.
The application of the heat-conducting particle filled plastic heat exchange material is that when the heat-conducting particle filled plastic heat exchange material is used as a heat exchange material of a heat exchanger or a heat dissipation material of an integrated circuit and an electronic device, the heat conductivity coefficient of the heat-conducting particle filled plastic heat exchange material is 0.5-5.5 W.m -1 ·K -1 Mechanical properties characterized by breaking strength500 to 1000 cN.
The invention has the advantages and beneficial effects that:
1. according to the heat-conducting particle filled type plastic heat exchange material, the porous membrane is selected as the base material of the heat exchange material heat-conducting main body, so that a large number of membrane pore canal (micro pore canal) structures are arranged in the heat-conducting main body, and when the membrane pore canal is filled with high-heat-conducting nano particles, the heat-conducting particle filled type plastic heat exchange material can be prepared after the construction of the compact layer on the outer surface.
2. According to the preparation method of the heat-conducting particle filled plastic heat exchange material, the preparation method of the compact layer is a sol-gel coating method, the contact angle of the surface of the prepared polydimethylsiloxane compact layer is as high as more than 120 ℃, and when steam is condensed on the surface of the polydimethylsiloxane compact layer, drop-shaped condensation is easy to occur, so that the steam condensation heat transfer performance of the heat exchange material is remarkably improved.
3. According to the preparation method of the heat-conducting particle filled type plastic heat exchange material, the porous membrane with poor heat conductivity is used as the base material of the heat-conducting main body of the filled type heat exchange material, and on one hand, the high porosity of 65% -85% enables the amount of heat-conducting particles which can be filled in the heat exchange material to be large; on the other hand, the heat conducting particles are gradually filled along the mass transfer micro-channel, so that the heat conducting particles form a heat conducting net chain in the mass transfer micro-channel, which is equivalent to the directional arrangement of the heat conducting particles along the heat conducting heat flow direction; both aspects will obviously promote the heat transfer material's heat conductivility, still avoided using the material that the heat conductivity is good as the substrate in prior art, exist when filling can provide mechanical properties material following two aspects problems: on the one hand, when the porosity of the base material is high, the proportion of the base material with good heat conductivity in the filled heat exchange material is low, so that the problem of poor heat conductivity of the filled heat exchange material is caused; on the other hand, when the porosity of the base material is low, the pore diameter in the base material is small, so that the filler with mechanical properties cannot be effectively filled into the pore canal, and the mechanical properties of the filled heat exchange material are seriously reduced.
4. According to the preparation method of the heat-conducting particle filled type plastic heat exchange material, the porous membrane is used as the base material of the heat-conducting main body of the filled type heat exchange material, the rib wires or the woven fibers in the membrane supporting layer provide main mechanical properties for the heat exchange material, and the main mechanical properties of the prepared heat-conducting particle filled type plastic heat exchange material are still provided by the rib wires or the woven fibers, so that the mechanical properties of the heat-conducting particle filled type plastic heat exchange material prepared by the preparation method are not obviously reduced, and the bottleneck problem that the heat-conducting properties and the mechanical properties of the filled type heat exchange material cannot be simultaneously achieved in a melt blending method and a solution blending method is well solved.
5. The heat conducting particle filled plastic heat exchange material has a heat conductivity coefficient of 0.5-5.5 W.m when the heat conducting particle filled plastic heat exchange material is used as a heat exchange material of a heat exchanger or a heat dissipation material of an integrated circuit and an electronic device -1 ·K -1 The mechanical property of the heat exchanger is 500-1000 cN, and the heat exchanger has great application potential in heat exchange materials of heat exchangers or heat dissipation materials of integrated circuits and electronic devices, and industries of smart phones, computers, intelligent household appliances, intelligent wearing and the like.
Drawings
FIG. 1 is a schematic flow diagram of an apparatus for filling hollow fiber PVDF microfiltration membrane heat conducting particles;
FIG. 2a is an SEM image of the inner surface of a polyvinylidene fluoride (PVDF) microfiltration membrane (M100-5.0-15) before filling with thermally conductive SiC nanoparticles;
FIG. 2b is an SEM image of the outer surface of a polyvinylidene fluoride (PVDF) microfiltration membrane (M100-5.0-15) prior to filling with thermally conductive SiC nanoparticles;
FIG. 2c is an SEM image of the inner surface of a polyvinylidene fluoride (PVDF) microfiltration membrane (M100-5.0-15) after filling with thermally conductive SiC nanoparticles;
FIG. 2d is an SEM image of the outer surface of a polyvinylidene fluoride (PVDF) microfiltration membrane (M100-5.0-15) after filling with thermally conductive SiC nanoparticles;
FIG. 3 is an SEM image of the outer surface of a thermally conductive SiC nanoparticle filled polyvinylidene fluoride (PVDF) heat exchange tube (T100-5.0-15);
description of the reference numerals
1-beaker, 2-peristaltic pump, 3-inlet valve, 4-pressure gauge, 5-needle, 6-microfiltration membrane, 7-measuring cylinder.
Detailed Description
The invention is further illustrated by the following examples, which are intended to be illustrative only and not limiting in any way.
Embodiment 1, a preparation method of a heat-conducting particle filled plastic heat exchange material, wherein the heat-conducting silicon carbide (SiC) nanoparticle filled hollow fiber PVDF heat exchange tube (T100-1.25-1.5, the sign meaning indicates that T is a heat exchange tube, 100-1.25-1.5 indicates that the particle size of the heat-conducting nanoparticle is 100 nm, the concentration of filling liquid is 1.25 wt% -the filling time is 1.5 min) is prepared.
The method comprises the following steps:
step 1) selecting a hollow fiber PVDF micro-filtration membrane (M0-0-0) which is not filled with SiC nano particles:
the porous membrane is used as a heat conduction main body of the plastic heat exchange material, and is a tubular membrane, a hollow fiber membrane or a flat membrane. The porosity of the porous membrane is 65% -85%, and the average pore diameter is 0.01-0.70 mu m. The porous membrane is composed of a supporting layer and a separating layer, and in order to improve the mechanical property of the plastic heat exchange material, the porous membrane material containing rib wires or woven fibers in the supporting layer is preferably selected; the separating layer material of the porous membrane is polyvinylidene fluoride, polysulfone, polyethersulfone, polyacrylonitrile, polyvinyl chloride, polypropylene or polytetrafluoroethylene; the material of the reinforcement wire is polyvinylidene fluoride, polytetrafluoroethylene, polyester or nylon, and the diameter of the reinforcement wire is 0.01-0.50 mm; the woven fiber material is selected from nylon, acrylic, polypropylene, terylene, polyvinyl chloride, vinylon, spandex or glass fiber, and the denier of the woven fiber material is 0.1-1.0 denier.
In the embodiment, a hollow fiber PVDF micro-filtration membrane which is not filled with SiC nano particles is selected from commercially available terylene-lined reinforced hollow fiber polyvinylidene fluoride (PVDF) porous micro-filtration membranes, which are named as M0-0-0 (the symbol mark meaning indicates that M is a micro-filtration membrane, 0-0-0 indicates that the particle size of the heat conducting nano particles is 0 nm, the concentration of filling liquid is 0 wt percent, and the filling time is 0 min). The external diameter of the polyvinylidene fluoride (PVDF) porous micro-filtration membrane M0-0-0 is 2.2 mm, and the section consists of a PVDF inner skin layer, a terylene lining layer and a PVDF outer skin layer. The PVDF inner skin layer and the PVDF outer skin layer are separating layers; the terylene lining layer is a supporting layer. The thickness of the PVDF inner and outer skin layers is 50 μm; the thickness of the terylene lining layer is 500 mu m; the porosity of the membrane was about 80%; the surface of the outer skin layer has membrane pores with an average pore diameter of 0.30 μm; the surface of the inner skin layer is provided with micron-sized holes distributed in a spongy shape.
Step 2) preparation of a heat-conducting SiC nanoparticle filled hollow fiber PVDF micro-filtration membrane (M100-1.25-1.5):
(1) and placing the heat-conducting nano particles in deionized water, stirring for 0.5-2.0 h at room temperature, and then performing ultrasonic treatment for 2.0-5.0 h to prepare a filling liquid with the concentration of 1.0-5.0 wt%. The heat conducting nano particles comprise metal, metal oxide, nitride and inorganic nonmetallic nano particles, and the inorganic nonmetallic nano particles comprise graphite, carbon black, carbon nano tube or silicon carbide or alumina or graphene.
The specific steps in this embodiment are: the heat conduction nano particles adopt heat conduction silicon carbide (SiC) nano particles with the particle size of 100 nm to be placed in deionized water, and the mixture is stirred at room temperature for 0.5 h and then is subjected to ultrasonic treatment for 2.0 h, so that a filling liquid with the concentration of 1.25 wt% is prepared.
(2) The filling liquid is taken as filtrate, a method of decompression filtration, ultrafiltration or microfiltration is adopted, the filtration is carried out for a certain time, and nano particles in the filling liquid are trapped in membrane pore canals of the porous membrane by utilizing the trapping characteristic of the membrane pores of the porous membrane, so that the filling of the membrane pore canals by the heat conducting nano particles in the filling liquid is realized.
The specific steps of the embodiment are as follows: any hollow fiber PVDF micro-filtration membrane with the length of 10 cm is taken, firstly soaked in absolute ethyl alcohol for 30 min to activate the hydrophilicity of the membrane pore canal and remove impurities in the membrane pore canal, the absolute ethyl alcohol in the membrane pore canal is replaced by deionized water, and one end of the micro-filtration membrane is blocked for standby. The flow of the hollow fiber PVDF micro-filtration membrane heat-conducting particle filling device is shown in figure 1. The filling liquid used as the micro-filtrate is put into a beaker 1, one end of the micro-filtration membrane 6, which is not blocked, is arranged on a needle 5, a peristaltic pump 2 is started, an inlet valve 3 of the filling liquid into the cavity of the micro-filtration membrane is regulated, the value of a pressure gauge 4 is 0.20 MPa, and the micro-filtration is carried out under the pressure, namely the filling operation is carried out for 1.5 min.
And (3) filling termination judgment: in the filling process, the filled microfiltration membrane is weighed in a wet state every 0.50 min, and the mass is not equal to1.3662 g (wet state) before filling gradually increases to 2.6307 g, and as the filling time is prolonged (i.e. more than 1.5 min), the quality of the micro-filtration membrane after filling is not increased any more, i.e. filling is stopped; or the mass transfer flux of the filled microfiltration membrane is measured on line in real time, and the mass transfer flux is 1213L m before being filled -2 ·h -1 Gradually decrease to 382L m -2 ·h -1 And when the filling time is prolonged more than 1.5 min, the mass transfer flux of the filled microfiltration membrane is not reduced any more, namely the filling is stopped.
(3) After filling, cleaning the inner cavity of the porous membrane for a certain time, and drying in an oven to prepare the heat-conducting particle filled membrane material.
The method comprises the following specific steps: after filling is finished, the inner cavity of the membrane is cleaned by 0.5 h, and is baked by 6.0 h to be dried in a baking oven at 70 ℃ to prepare the heat conduction SiC nanoparticle filled hollow fiber PVDF micro-filtration membrane which is named as M100-1.25-1.5 (the code label meaning indicates that M is the micro-filtration membrane, and 100-1.25-1.5 indicates that the particle size of the heat conduction nanoparticle is 100 nm, the concentration of filling liquid is 1.25 wt percent and the filling time is 1.5 min). During the filling process, the volume of the filtered liquid is collected by the dosage cylinder 7, so that the mass transfer flux of the microfiltration membrane is monitored in real time.
Step 3) preparation of a heat conduction SiC nanoparticle filled hollow fiber PVDF heat exchange tube (T100-1.25-1.5):
(1) weighing a certain amount of polydimethylsiloxane as a precursor, dissolving the precursor in a solvent of normal hexane, magnetically stirring at room temperature for 0.5-2.0 h, adding a certain amount of heat-conducting nano particles, continuing to magnetically stir for 0.5-2.0 h, and then performing ultrasonic treatment for 2.0-5.0 h to ensure uniform particle dispersion, thereby obtaining a dispersion liquid with the concentration of polydimethylsiloxane of 5-30 wt% and the addition amount of the heat-conducting nano particles of 0.5-8.0 wt%; the heat conducting nano particles comprise metal, metal oxide, nitride and inorganic nonmetallic nano particles, and the inorganic nonmetallic nano particles comprise graphite, carbon black, carbon nano tubes, silicon carbide, aluminum oxide and graphene.
The method comprises the following specific steps:
adding polydimethylsiloxane into a beaker containing n-hexane (serving as a solvent), preparing a solution with the concentration of dimethylsiloxane being 25 wt%, magnetically stirring at room temperature for 0.5 h after sealing by using a preservative film, adding zinc oxide particles with the average particle size of 100 nm, adding zinc oxide with the addition amount of 4.0 wt%, magnetically stirring for 0.5 h continuously and ultrasonically stirring for 2.0 h to ensure uniform particle dispersion, and obtaining a dispersion liquid.
(2) Ethyl orthosilicate and dibutyltin dilaurate as a crosslinking agent and a catalyst were slowly dropped into the dispersion liquid and stirred for 0.5. 0.5 h to be uniform, thereby preparing a coating solution having concentrations of 5 wt% of both ethyl orthosilicate and dibutyltin dilaurate.
(3) Placing the filled microfiltration membrane M100-1.25-1.5 obtained in the step 2) into the stirred coating solution, coating for 45min while stirring, taking out, standing for 12h at room temperature, and then placing into a 70 ℃ oven for curing for 10h to obtain a filled hollow fiber PVDF heat exchange tube with a compact layer on the outer surface, wherein the heat exchange tube is named as T100-1.25-1.5 (code label meaning description: t is a heat exchange tube, 100 represents that the particle size of the heat conduction nano particles is 100 nm,1.25 represents that the concentration of the filling liquid is 1.25 and wt percent, and 1.5 represents that the filling time is 1.5 min).
Examples 2 to 15
In the embodiment 2-15, 14 preparation methods of heat-conducting particle filled plastic heat exchange materials are adopted, and the preparation methods in the embodiment 2-15 are respectively adopted to obtain the heat-conducting SiC nanoparticle filled hollow fiber PVDF heat exchange tube T100-1.25-3.0, T100-1.25-5.0, T100-1.25-15, T100-1.25-30, T100-0.3125-15, T100-0.625-15, T100-1.25-15, T100-2.5-15, T100-5.0-15, T50-1.25-1.5, T50-1.25-3.0, T50-1.25-5.0, T50-1.25-15 and T50-1.25-30. (the sign meaning indicates that T is a heat exchange tube, and the sign meaning is that the particle size of the T heat conduction nano particles is nm, the concentration of the filling liquid is wt% -the filling time is min).
Examples 2-15, the preparation of 14 kinds of heat-conducting particle filled plastic heat exchange materials comprises the following steps:
The hollow fiber PVDF micro-filtration membrane which is not filled with SiC nano particles in the step 1) is still a porous membrane M0-0-0.
Step 2) preparing 14 heat conduction SiC nanoparticle filled hollow fiber PVDF micro-filtration membranes M100-1.25-3.0, M100-1.25-5.0, M100-1.25-15, M100-1.25-30, M100-0.3125-15, M100-0.625-15, M100-1.25-15, M100-2.5-15, M100-5.0-15, M50-1.25-1.5, M50-1.25-3.0, M50-1.25-5.0, M50-1.25-15 and M50-1.25-30 respectively. (the code mark meaning indicates that M is a microfiltration membrane, and the code meaning is that the particle size of the M heat-conducting nano particles is nm, the concentration of the filling liquid is wt% -the filling time is min).
The preparation method of the 14 heat-conducting SiC nanoparticle filled hollow fiber PVDF micro-filtration membranes is the same as M100-1.25-1.5 in example 1, except that heat-conducting SiC nanoparticles with different particle diameters are selected and respectively filled under different filling liquid concentrations and filling times, as shown in Table 1.
And 3) respectively preparing 14 heat conduction SiC nanoparticle filled hollow fiber PVDF heat exchange tubes T100-1.25-3.0, T100-1.25-5.0, T100-1.25-15, T100-1.25-30, T100-0.3125-15, T100-0.625-15, T100-1.25-15, T100-2.5-15, T100-5.0-15, T50-1.25-1.5, T50-1.25-3.0, T50-1.25-5.0, T50-1.25-15 and T50-1.25-30. The preparation method of the 14 heat-conducting SiC nanoparticle filled hollow fiber PVDF heat exchange tubes comprises the step of preparing 14 heat-conducting SiC nanoparticle filled hollow fiber PVDF micro-filtration membranes prepared in the step 2) by adopting the same preparation process as that of the hollow fiber PVDF heat exchange tubes prepared in the step 1) without 3) T100-1.25-1.5.
Comparative example 1, a method for preparing a plastic heat exchange material without SiC nanoparticles, the hollow fiber PVDF heat exchange tube (T0-0-0) without SiC nanoparticles was prepared in this example.
The preparation method comprises the following steps:
the hollow fiber PVDF micro-filtration membrane which is not filled with SiC nano particles in the step 1) is still a porous membrane M0-0-0.
And 2) preparing the hollow fiber PVDF heat exchange tube T0-0-0 without filling the SiC nano particles. Prepared by the same preparation process as T100-1.25-1.5 in step 3) of example 1.
Basic performances of the hollow fiber PVDF microfiltration membrane without the SiC nanoparticles in comparative example 1) of the heat conduction SiC nanoparticle filled hollow fiber PVDF microfiltration membrane prepared in examples 1 to 15:
15 kinds of heat conduction SiC nanoparticle filled hollow fibers prepared in examples 1-15Specific filling parameters and basic properties of the dimensional PVDF microfiltration membranes M100-1.25-1.5, M100-1.25-3.0, M100-1.25-5.0, M100-1.25-15, M100-1.25-30, M100-0.3125-15, M100-0.625-15, M100-1.25-15, M100-2.5-15, M100-5.0-15, M50-1.25-1.5, M50-1.25-3.0, M50-1.25-5.0, M50-1.25-15, M50-1.25-30 are set forth in Table 1. M-0-0-0 in Table 1 is the substrate of the above 15 heat conductive SiC nanoparticle filled hollow fiber PVDF microfiltration membranes prior to filling, i.e., the hollow fiber PVDF microfiltration membrane of comparative example 1 that is not filled with SiC nanoparticles. 15 heat conduction SiC nanoparticle filled hollow fiber PVDF micro-filtration membranes have a heat conduction coefficient of 1.58-3.01 W.m at room temperature -1 ·K -1 4.79 to 9.12 times higher than the (M-0-0-0) before filling; the breaking strength is 825-873 cN, which is reduced by 0.11% -5.61% compared with the breaking strength before filling (M-0-0-0); mass transfer flux is 43-382 L.m -2 ·h -1 Compared with the unfilled material (M-0-0-0 is 1213L M -2 ·h -1 ) The significant reduction indicates that the thermally conductive SiC nanoparticles filled into the membrane mass transfer microchannel through step 2) severely block the transmural permeation of the fluid on both sides of the membrane, which would significantly reduce the mechanical requirements of the dense layer that step 3) needs to prepare. Fig. 2 is an SEM image of the inner and outer surfaces of a polyvinylidene fluoride (PVDF) microfiltration membrane (M100-5.0-15) filled with thermally conductive silicon carbide (SiC) nanoparticles, and the inner and outer surfaces c and d after filling are filled with a large amount of thermally conductive SiC nanoparticles compared with the inner and outer surfaces a and b of the membrane (M-0-0-0) before filling, which is a direct cause of a significant improvement in thermal conductivity and a significant reduction in mass transfer flux after filling.
Table 1. Specific packing parameters and basic Performance lists for SiC nanoparticle-filled hollow fiber PVDF microfiltration membranes
Figure SMS_3
a : and testing the heat conductivity coefficient by adopting a heat conduction instrument at room temperature, wherein before testing, the filled PVDF micro-filtration membrane is soaked in absolute ethyl alcohol for 20 min, and then deionized water is used for replacing the membrane, so that liquid water is filled in the rest gaps in the pore canal.
b : transmission deviceThe mass flux was measured at room temperature using a flux measuring device, using deionized water (without nanoparticles) as the microfilter.
Basic performances of the heat-conducting SiC nanoparticle filled hollow fiber PVDF heat exchange tube prepared in examples 1-15 and the hollow fiber PVDF heat exchange tube without SiC nanoparticle in comparative example 1:
the basic properties of the total 15 heat-conducting SiC nanoparticle filled hollow fiber PVDF heat exchange tubes T100-1.25-1.5, T100-1.25-3.0, T100-1.25-5.0, T100-1.25-15, T100-1.25-30, T100-0.3125-15, T100-0.625-15, T100-1.25-15, T100-2.5-15, T100-5.0-15, T50-1.25-1.5, T50-1.25-3.0, T50-1.25-5.0, T50-1.25-15, T50-1.25-30 prepared in examples 1-15 are listed in Table 2. T-0-0-0 in Table 2 is a hollow fiber PVDF heat exchange tube without SiC nanoparticles filled in comparative example 1. 15 heat conduction SiC nanoparticle filled hollow fiber PVDF heat exchange tubes have a heat conduction coefficient of 0.99-2.40 W.m at room temperature -1 ·K -1 3.09-7.50 times higher than the unfilled (T-0-0-0); the breaking strength is 812-858 cN, which is reduced by 0.23% -5.58% compared with the breaking strength before filling (T-0-0-0); the porosity is 31.4-49.8%, which is reduced by 31.8-57.0% compared with the porosity (T-0-0-0) before filling; the contact angle of the surface is 122 degrees, 45 degrees is improved compared with an unfilled microfiltration membrane (M-0-0-77 degrees), the surface has better hydrophobicity, and when steam is condensed on the surface, drop-shaped condensation is easy to occur, so that the steam condensation heat transfer performance of the heat exchange material can be obviously improved; mass transfer flux is 43-382 L.m before dense layer is not constructed -2 ·h -1 All drop to 0L m -2 ·h -1 The method shows that the micro-filtration membrane with the function of mass transfer and separation of the transmembrane wall can be prepared into the heat exchange tube which can completely prevent cold and hot fluid at two sides of the tube from penetrating across the tube wall after the step 2) and the step 3). FIG. 3 is an SEM image of the outer surface of a heat-conducting silicon carbide (SiC) nanoparticle filled PVDF heat exchange tube (T100-5.0-15), and the finding that a large number of membrane pores and heat-conducting particles on the outer surface of a filled PVDF microfiltration membrane are completely covered by a polydimethylsiloxane compact layer, namely the outer surface of the filled PVDF heat exchange tube is compact and nonporous, which is 43-382 L.m before the mass transfer flux of the heat-conducting SiC nanoparticle filled hollow fiber PVDF heat exchange tube is not constructed by the compact layer -2 ·h -1 All drop to 0L m -2 ·h -1 For a direct reason of (2).
Table 2. Basic performance lists of SiC nanoparticle filled hollow fiber PVDF heat exchange tubes and hollow fiber PVDF heat exchange tubes without SiC nanoparticles
Figure SMS_4
a : and testing the heat conductivity coefficient by adopting a heat conduction instrument at room temperature, wherein before testing, the filled PVDF micro-filtration membrane is soaked in absolute ethyl alcohol for 20 min, and then deionized water is used for replacing the membrane, so that liquid water is filled in the rest gaps in the pore canal.
b : mass transfer flux was tested at room temperature using a flux testing device, with deionized water (without nanoparticles) as the microfilter.
In Table 2, comparative example 1 (T-0-0-0) is a hollow fiber PVDF heat exchange tube that is not filled with SiC nanoparticles. As can be seen from a comparison of T-0-0-0 in Table 2 with M-0-0 in Table 1, after a dense layer was formed on the outer surface of the hollow fiber PVDF micro-filtration membrane without the SiC nanoparticles to form a heat exchange tube, the breaking strength was reduced from 874 cN to 860 cN before the dense layer was formed, the porosity was reduced from 80.0% to 73.0% before the dense layer was formed, and the thermal conductivity was reduced from 0.33W.m before the dense layer was formed -1 ·K -1 Drop to 0.32W m -1 ·K -1 Mass transfer flux was determined from 1213L.m before dense layer build-up -2 ·h -1 Drop to 246L m -2 ·h -1 Instead of the mass transfer flux after the dense layer construction as in examples 1 to 15 being reduced to 0L. Mu.m -2 ·h -1 . This is because comparative example 1 did not undergo thermally conductive SiC nanoparticle packing, i.e., did not have the blocking effect of SiC nanoparticles on the transmural mass transfer of fluids on both sides of the membrane, and the dense layer constructed just by the outer surface as in examples 1-15 could not completely block the transmural mass transfer of fluids on both sides of the membrane, so the mass transfer flux, although significantly reduced, was not 0L ·m -2 ·h -1 。
Examples 16 to 33
In embodiments 16 to 33, a method for preparing 18 kinds of heat conductive particle filled plastic heat exchange materials comprises the following steps:
the porous membrane parameters for the unfilled thermally conductive nanoparticles selected for step 1) are listed in table 3. The main difference from the polyester lining reinforced hollow fiber PVDF porous microfiltration membrane M0-0-0 selected in example 1 is that the hollow fiber PVDF ultrafiltration membrane is selected in examples 16-21, the polyester lining reinforced PVDF porous flat membrane is selected in examples 22-27, and the tubular membrane made of polyethersulfone is selected in examples 28-33.
Table 3 list of parameters of the porous films of the unfilled nanoparticles selected for examples 16-33 and comparative examples 2-7
Figure SMS_5
Step 2) 18 kinds of heat conductive nanoparticle filled porous membranes were prepared separately, and main parameters and basic properties of the filling preparation are listed in table 4. The preparation method of the 18 heat conduction nanoparticle filling type porous membranes is the same as M100-1.25-1.5 in the embodiment 1, and the main difference is that the porous membranes selected in the step 1) are filled by different filling methods and different types of heat conduction nanoparticles.
Table 4. Examples 16 to 33 nanoparticle filled porous films Main filling parameters and basic Performance Table (including comparative examples 2 to 7)
Figure SMS_6
a : the thermal conductivity coefficient is tested at room temperature by adopting a thermal conductivity meter, and before the test, the filled porous membrane is soaked in absolute ethyl alcohol for 20 min and replaced by deionized water, so that the liquid water is filled in the rest gaps in the pore canal.
b : the mass transfer flux was measured at room temperature using a flux measuring device using deionized water (without nanoparticles) as the fill fluid.
Step 3) 18 kinds of heat-conducting nanoparticle filled heat exchange tubes were prepared respectively, and the main parameters and basic properties of the coating preparation are listed in table 5. The coating preparation method of the 18 heat conduction nanoparticle filling type heat exchange tubes is that 18 heat conduction nanoparticle filling type porous films prepared in the step 2) are prepared by adopting preparation processes similar to T100-1.25-1.5 in the embodiment 1, and the main difference is that 18 heat conduction nanoparticle filling type porous films prepared in the step 2) are coated by selecting heat conduction nanoparticles with different types and different particle diameters to prepare a compact layer.
Table 5. Example 16 to 33 nanoparticle filled Heat exchange tube coating preparation Main parameters and basic Performance Table (comparative examples 2 to 7)
Figure SMS_7
a : the thermal conductivity coefficient is tested at room temperature by adopting a thermal conductivity meter, and before the test, the filled porous membrane is soaked in absolute ethyl alcohol for 20 min and replaced by deionized water, so that the liquid water is filled in the rest gaps in the pore canal.
b : mass transfer flux was tested at room temperature using a flux testing device, with deionized water (without nanoparticles) as the microfilter.
c : refers to silicon carbide nanoparticles; d : refers to graphene nanoparticles.
Comparative examples 2 to 7
Comparative examples 2-7, a total of 6 methods for preparing plastic heat exchange materials without filling heat conducting nanoparticles, comprising the following steps:
step 1) 6 porous film parameters for unfilled thermally conductive nanoparticles are listed in table 3. The main difference from the polyester lining reinforced hollow fiber PVDF porous micro-filtration membrane M0-0-0 selected in comparative example 1 is that the hollow fiber PVDF micro-filtration membrane is selected in comparative example 2-3, the polyester lining reinforced PVDF porous flat membrane is selected in comparative example 4-5, and the tubular membrane is selected in comparative example 6-7.
And 2) preparing 6 heat exchange tubes not filled with heat conducting nano particles. The main parameters and basic properties of the coating preparation are listed in table 5. The preparation method of the heat exchange tube coating of the 6 unfilled heat conduction nano particles is that the porous films of the 6 unfilled heat conduction nano particles selected in the step 1) are respectively prepared by adopting a preparation process similar to M0-0-0 in the comparative example 1, and the main difference is that the porous films of the 6 unfilled heat conduction nano particles selected in the step 1) are coated by selecting heat conduction nano particles with different types and different particle diameters to prepare a compact layer.
Basic properties of the heat conductive nanoparticle filled porous films prepared in examples 16 to 33 and the porous films of comparative examples 2 to 7 not filled with nanoparticles:
the basic properties of 18 total thermally conductive nanoparticle-filled porous membranes prepared in examples 16-33 are listed in table 4. In table 4, comparative example 2 is comparative examples of examples 16 to 18, comparative example 3 is comparative examples of examples 19 to 21, comparative example 4 is comparative examples of examples 22 to 24, comparative example 5 is comparative examples of examples 25 to 27, comparative example 6 is comparative examples of examples 28 to 30, and comparative example 7 is comparative examples of examples 31 to 33. The heat conductivity coefficient of the 18 heat conduction nanoparticle filled porous membranes at room temperature is 0.96-5.20 W.m -1 ·K -1 The filling process is improved by 1.82-14.76 times compared with the process before filling; the breaking strength is 742-852 cN, which is reduced by 0.92-4.98% compared with the breaking strength before filling; mass transfer flux is 18-188 L.m -2 ·h -1 Compared with the unfilled material (985-1147 L.m) -2 ·h -1 ) Significantly reduced.
Basic properties of the heat transfer nanoparticle filled heat transfer tubes prepared in examples 16 to 33 and the heat transfer tubes without nanoparticle filled in comparative examples 2 to 7:
the basic properties of 18 kinds of heat transfer nanoparticle filled heat exchange tubes prepared in examples 16 to 33 are shown in table 5. In table 5, comparative example 2 is comparative examples of examples 16 to 18, comparative example 3 is comparative examples of examples 19 to 21, comparative example 4 is comparative examples of examples 22 to 24, comparative example 5 is comparative examples of examples 25 to 27, comparative example 6 is comparative examples of examples 28 to 30, and comparative example 7 is comparative examples of examples 31 to 33. The heat conductivity coefficient of the 18 heat conduction nanoparticle filled heat exchange tube at room temperature is 0.92-5.15 W.m -1 ·K -1 Compared withThe filling is improved by 1.79 to 15.6 times before the filling; the breaking strength is 729-841 cN, which is reduced by 0.12% -3.30% compared with the breaking strength before filling; the porosity is 36.8-46.7%, and is reduced by 43.7-54.6% compared with the porosity before filling; the contact angle of the surface is 121 degrees, the surface has better hydrophobicity, when the steam is condensed on the surface, drop-shaped condensation is easy to occur, and the steam condensation heat transfer performance of the heat exchange material can be obviously improved; mass transfer flux is 18-188 L.m before dense layer is not constructed -2 ·h -1 All drop to 0L m -2 ·h -1 。
In table 5, comparative examples 2 to 7 are porous heat exchange tubes not filled with thermally conductive nanoparticles. As is clear from comparison of comparative examples 2 to 7 in tables 3, 4 and 5, after a dense layer is formed on the outer surface of a porous film not filled with heat conductive nanoparticles to form a heat exchange material, the breaking strength is reduced from 759 to 862 cN to 737 to 849 cN before the dense layer is not formed, the porosity is reduced from 80 to 85% to 77 to 83% before the dense layer is not formed, and the heat conductivity is reduced from 0.32 to 0.34 W.m before the dense layer is not formed -1 ·K -1 The drop is 0.30-0.33 W.m -1 ·K -1 The mass transfer flux is 985-1004 L.m before the compact layer is not constructed -2 ·h -1 Drop to 179-236 L.m -2 ·h -1 Instead of the mass transfer flux after the dense layer construction as in examples 16 to 33 being reduced to 0L. Mu.m -2 ·h -1 . This is because comparative examples 2 to 7 did not undergo thermal nanoparticle filling, i.e., there was no blocking effect of nanoparticles on the transmural mass transfer of fluids on both sides of the membrane, and the dense layer constructed just by the outer surface as in examples 16 to 33 could not completely block the transmural mass transfer of fluids on both sides of the membrane, so the mass transfer flux, although significantly reduced, was not 0L ·m -2 ·h -1 。
Although the embodiments of the present invention and the accompanying drawings have been disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and thus the scope of the invention is not limited to the embodiments and the disclosure of the drawings.

Claims (10)

1. The preparation method of the heat-conducting particle filled plastic heat exchange material is characterized by comprising the following steps of:
step 1) selecting a porous membrane:
a porous membrane is adopted as a heat conduction main body of the plastic heat exchange material;
step 2) preparation of a heat conducting particle filling type film material:
(1) placing the heat conduction nano particles in deionized water, stirring for 0.5-2.0 h at room temperature, and then performing ultrasonic treatment for 2.0-5.0 h to prepare filling liquid with the concentration of 1.0-5.0 wt%;
(2) filtering by taking filling liquid as filtrate and adopting a method of reduced pressure filtration, ultrafiltration or microfiltration for 10-60 min, and utilizing the interception characteristic of the membrane pore canal of the porous membrane to intercept nano particles in the filling liquid in the membrane pore canal of the porous membrane so as to realize the filling of the heat conduction nano particles in the filling liquid to the membrane pore canal;
(3) after filling, cleaning the inner cavity of the porous membrane for 0.2-1.0 h, and then drying in an oven at 65-75 ℃ for 4.0-8.0 h to dryness to prepare a heat-conducting particle filled membrane material;
Step 3) preparation of a heat-conducting particle filled plastic heat exchange material:
(1) weighing a certain amount of polydimethylsiloxane as a precursor, dissolving the precursor in a solvent of normal hexane, magnetically stirring at room temperature for 0.5-2.0 h, adding heat-conducting nano particles, continuing to magnetically stir for 0.5-2.0 h, and then performing ultrasonic treatment for 2.0-5.0 h to ensure uniform particle dispersion, thereby obtaining a dispersion liquid with the concentration of polydimethylsiloxane of 5-30 wt% and the addition amount of the heat-conducting nano particles of 0.5-8.0 wt%;
(2) slowly dripping ethyl orthosilicate and dibutyl tin dilaurate serving as a cross-linking agent and a catalyst into the dispersion liquid, and stirring for 0.5-2.0 h to be uniform to prepare a coating solution with the concentration of both ethyl orthosilicate and dibutyl tin dilaurate of 1.0-6.0 wt%;
(3) placing the heat conducting particle filled film material into the stirred coating solution, and coating for 10-60 min while stirring; and (3) placing the coated filled heat exchange material for 6-24 hours at room temperature, and placing the coated filled heat exchange material into an oven at 65-75 ℃ for curing for 6-24 hours to obtain the heat conduction particle filled plastic heat exchange material with the compact layer on the surface.
2. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the porous membrane in step 1) comprises a tubular membrane, a hollow fiber membrane or a flat membrane.
3. The method for preparing a heat conductive particle filled plastic heat exchange material according to claim 1 or 2, characterized in that: the porosity of the porous membrane is 65% -85%, and the average pore diameter is 0.01-0.70 mu m.
4. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the porous membrane consists of a supporting layer and a separating layer, wherein the supporting layer of the porous membrane contains threads or woven fibers; the separating layer material of the porous membrane is polyvinylidene fluoride, polysulfone, polyethersulfone, polyacrylonitrile, polyvinyl chloride, polypropylene or polytetrafluoroethylene; the reinforcement wire material is polyvinylidene fluoride, polytetrafluoroethylene, polyester or nylon, and the diameter of the reinforcement wire is 0.01-0.50 mm; the woven fiber material is selected from nylon, acrylic, polypropylene, terylene, polyvinyl chloride, vinylon, spandex or glass fiber, and the denier of the woven fiber material is 0.1-1.0 denier.
5. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the heat conduction nano particles in the step 2) comprise metal, metal oxide, nitride and inorganic nonmetallic nano particles, wherein the inorganic nonmetallic nano particles comprise graphite, carbon black, carbon nano tubes, silicon carbide, aluminum oxide or graphene, and the particle size of the heat conduction nano particles is 15-100 nm.
6. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the step 2) comprises a filling termination judging step, wherein the judging method comprises a weighing method or a mass transfer flux measuring method, and the weighing method comprises the following steps: weighing the filled porous membrane, and stopping filling when the mass is no longer increased; the mass transfer flux assay is: and measuring the mass transfer flux of the filled porous membrane, and stopping filling when the mass transfer flux is no longer reduced.
7. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the dense layer preparation method in the step 3) is a sol-gel coating method.
8. The method for preparing the heat conductive particle filled plastic heat exchange material according to claim 1, wherein the method comprises the following steps: the heat conduction nano particles in the step 3) comprise metal, metal oxide, nitride and inorganic nonmetallic nano particles, wherein the inorganic nonmetallic nano particles comprise graphite, carbon black, carbon nano tubes, silicon carbide, aluminum oxide or graphene, and the particle size of the heat conduction nano particles is 15-100nm.
9. A heat-conducting particle filled plastic heat exchange material is characterized in that: the heat conductivity coefficient of the heat-conducting particle filled plastic heat exchange material at room temperature is 0.5-5.5 W.m -1 ·K -1 The mechanical property of the steel is 500-1000 cN, which is characterized by breaking strength;
the preparation method of the heat-conducting particle filled plastic heat exchange material comprises the following steps:
step 1) selecting a porous membrane:
a porous membrane is adopted as a heat conduction main body of the plastic heat exchange material;
step 2) preparation of a heat conducting particle filling type film material:
(1) placing the heat conduction nano particles in deionized water, stirring for 0.5-2.0 h at room temperature, and then performing ultrasonic treatment for 2.0-5.0 h to prepare filling liquid with the concentration of 1.0-5.0 wt%;
(2) filtering by taking filling liquid as filtrate and adopting a method of reduced pressure filtration, ultrafiltration or microfiltration for 10-60 min, and utilizing the interception characteristic of the membrane pore canal of the porous membrane to intercept nano particles in the filling liquid in the membrane pore canal of the porous membrane so as to realize the filling of the heat conduction nano particles in the filling liquid to the membrane pore canal;
(3) after filling, cleaning the inner cavity of the porous membrane for 0.2-1.0 h, and then drying in an oven at 65-75 ℃ for 4.0-8.0 h to dryness to prepare a heat-conducting particle filled membrane material;
step 3) preparation of a heat-conducting particle filled plastic heat exchange material:
(1) weighing a certain amount of polydimethylsiloxane as a precursor, dissolving the precursor in a solvent of normal hexane, magnetically stirring at room temperature for 0.5-2.0 h, adding heat-conducting nano particles, continuing to magnetically stir for 0.5-2.0 h, and then performing ultrasonic treatment for 2.0-5.0 h to ensure uniform particle dispersion, thereby obtaining a dispersion liquid with the concentration of polydimethylsiloxane of 5-30 wt% and the addition amount of the heat-conducting nano particles of 0.5-8.0 wt%;
(2) Slowly dripping ethyl orthosilicate and dibutyl tin dilaurate serving as a cross-linking agent and a catalyst into the dispersion liquid, and stirring for 0.5-2.0 h to be uniform to prepare a coating solution with the concentration of both ethyl orthosilicate and dibutyl tin dilaurate of 1.0-6.0 wt%;
(3) placing the heat conducting particle filled film material into the stirred coating solution, and coating for 10-60 min while stirring; and (3) placing the coated filled heat exchange material for 6-24 hours at room temperature, and placing the coated filled heat exchange material into an oven at 65-75 ℃ for curing for 6-24 hours to obtain the heat conduction particle filled plastic heat exchange material with the compact layer on the surface.
10. Use of a heat conductive particle filled plastic heat exchange material as claimed in claim 9 wherein: when the heat-conducting particle filled plastic heat exchange material is used as a heat exchange material of a heat exchanger or a heat dissipation material of an integrated circuit and an electronic device, the heat conductivity coefficient of the heat-conducting particle filled plastic heat exchange material is 0.5-5.5 W.m -1 ·K -1 The mechanical property of the alloy is 500-1000 cN.
CN202310627231.4A 2023-05-31 2023-05-31 Heat-conducting particle filled plastic heat exchange material and preparation method and application thereof Active CN116333368B (en)

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120085698A1 (en) * 2009-12-07 2012-04-12 Xinhao Yang Method for preparing composite multilayer porous hollow membrane and device and product thereof
CN103834127A (en) * 2014-02-27 2014-06-04 华南理工大学 Micro nanocomposite material with high thermal conductivity and preparation method thereof
KR20150101243A (en) * 2014-02-26 2015-09-03 (주)필로스 Membrane and the membrane manufacture method
CN110003654A (en) * 2019-03-01 2019-07-12 陈莹 A kind of preparation method of high heat conducting insulating silicon grease material
CN110054864A (en) * 2018-12-25 2019-07-26 上海交通大学 A kind of preparation method of high thermal conductivity compounded mix and its polymer matrix composite
CN110511426A (en) * 2019-08-09 2019-11-29 中山市福维环境科技有限公司 A kind of composite polymer material film and preparation method thereof
CN110746757A (en) * 2019-10-31 2020-02-04 华中科技大学 High-thermal-conductivity biodegradable polymer composite material and preparation method thereof
CN112812341A (en) * 2021-02-09 2021-05-18 桂林电子科技大学 High-thermal-conductivity composite particle/polyimide film with four-needle-shaped structure and preparation method thereof
CN113845740A (en) * 2020-06-11 2021-12-28 四川大学 Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120085698A1 (en) * 2009-12-07 2012-04-12 Xinhao Yang Method for preparing composite multilayer porous hollow membrane and device and product thereof
KR20150101243A (en) * 2014-02-26 2015-09-03 (주)필로스 Membrane and the membrane manufacture method
CN103834127A (en) * 2014-02-27 2014-06-04 华南理工大学 Micro nanocomposite material with high thermal conductivity and preparation method thereof
CN110054864A (en) * 2018-12-25 2019-07-26 上海交通大学 A kind of preparation method of high thermal conductivity compounded mix and its polymer matrix composite
CN110003654A (en) * 2019-03-01 2019-07-12 陈莹 A kind of preparation method of high heat conducting insulating silicon grease material
CN110511426A (en) * 2019-08-09 2019-11-29 中山市福维环境科技有限公司 A kind of composite polymer material film and preparation method thereof
CN110746757A (en) * 2019-10-31 2020-02-04 华中科技大学 High-thermal-conductivity biodegradable polymer composite material and preparation method thereof
CN113845740A (en) * 2020-06-11 2021-12-28 四川大学 Preparation method of high-thermal-conductivity polytetrafluoroethylene composite film material
CN112812341A (en) * 2021-02-09 2021-05-18 桂林电子科技大学 High-thermal-conductivity composite particle/polyimide film with four-needle-shaped structure and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
俞丽芸;许振良;韩灵凤;: "PVDF-SiO_2中空纤维复合膜的制备和表征", 华东理工大学学报(自然科学版), no. 01 *
贾巍;高启君;吕晓龙;陈华艳;王暄;董畅;: "PVDF中空纤维换热管亲/疏水组合表面强化蒸汽冷凝传热", 化工学报, no. 07 *

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