71results about How to "Phase transition temperature is suitable" patented technology

The invention relates to a preparation method of an interpenetrating network formed phase-change material, comprising the following steps of: adding N-hydroxymethyl acrylamide as a network monomer, N, N-methylene-bisacrylamide as a cross linking agent, polyethylene glycol as a phase-change material and distilled water into a flask, ultrasonic-dispersing for 5 minutes after dissolving (the molar ratio of the cross linking agent to the network monomer is (1/7):(1/11), the mass ratio of the network monomer to the water is (1/6):(1/14), and the proportion of the polyethylene glycol accounts for 40-80 percent of the total mass); adding ammonium persulfate as an initiator and continuously ultrasonic-dispersing for 5 minutes, wherein the mass fraction of the initiator accounts for 1.5-3.5 percent of the network monomer; and reacting at a temperature of 70-80 DEG C for 3-4 hours to generate interpenetrating network hydrogel, and then drying to a constant weight to obtain the interpenetrating network formed phase-change material. The preparation method has a simple process and a low production cost and is friendly to environment. Moreover, the phase-change material has the advantages of high enthalpy (reaching over 108.41J/g), less loss, suitable phase-change temperature (32-42 DEG C) and good performance in high temperature resistance.

The present invention relates to a kind of high molecular solid/solid phase changing material with mixed net and comb structure, and features that polyglycol with two active end radical and polyglycol with one active end radical are fixed onto the high molecular skeleton material to form 3D mixed net and comb structure. The material of the present invention has relatively great phase change enthalpy up to 120 J/g, proper phase change temperature capable of being altered in 0-65 deg.c, stable solid state before and after phase change without supercooling, separating and other unstable phenomenon, high mechanical strength, high solvent resistance, good machining performance, no toxicity, no leakage, no corrosion, no pollution, long service life and other advantages. The present invention may be used widely in solar energy utilization, afterheat recovering, intelligent air conditioner and other fields.

The invention relates to a mining temperature reduction coolant and preparation method thereof. The invention takes macromolecular compound polyvinyl alcohol as basic raw material, cross-linking agent in certain proportion is added, wherein the cross-linking agent is 10% borax solution and the like; then freezing point temperature reduction auxiliary agent is added to prepare gel-like coolant, the prepared coolant is injected into a forming container and is frozen and formed in an icehouse the temperature of which is lower than minus 15 DEG C, and then the formed coolant is unfrozen at room temperature and is filled into a packaging bag. The mining temperature reduction coolant of the invention has the following characteristics: (1) elasticity and flexibility are good, comfortable sensation can be obtained when human body touches the coolant; (2) cold accumulation material has major latent heat of phase change and appropriate phase change temperature; (3) the coolant can be repeatedly used, can not be cataklastic, can not contract and can produce no separated water; (4) the coolant can be in close contact with human body when in use, and refrigeration effect can be fully played; (5) no toxin, odour or pollution is produced; (6) cold insulating plate and cold insulating bag of the outer packing of the coolant has the function of 'environmental protection and high efficiency cold insulation heat preservation'.

The invention discloses a boron nitride/graphene double-heat-conduction-base aerogel composite phase change material. The material is formed by compounding modified boron nitride/graphene aerogel andn-octadecane by adopting a vacuum impregnation method. The double-heat-conduction aerogel is prepared by taking graphene oxide, modified boron nitride, polyvinylpyrrolidone and ethylenediamine as rawmaterials to prepare boron nitride/graphene hydrogel, freeze-drying the boron nitride/graphene hydrogel and then calcining the boron nitride/graphene hydrogel at a constant temperature. Polyvinylpyrrolidone is used as a cross-linking agent, and ethylenediamine is used as a reducing agent. A preparation method of the composite phase change material comprises the following steps: 1) preparing modified boron nitride; 2) preparing boron nitride/graphene double-heat-conduction-base aerogel; and 3) preparing the boron nitride/graphene double-heat-conduction-base aerogel composite phase change material. When the material is applied as a phase change material, the heat conductivity coefficient is 0.9-1.6 W/(m.K); wherein the phase change temperature is 19-32 DEG C, and the phase change latent heatis 200-220 J/g. The composite phase change material has the following advantages: 1, the heat conductivity coefficient is improved by 738%; 2, the leakage problem in the phase change process is effectively solved; and 3, the phase-change latent heat and the heat stability are high;

The invention provides a phase-change thermal energy-storage material applicable to a heat-pump water heater. The phase-change thermal energy-storage material comprises, by weight, 20 to 30 of stearic acid, 30 to 40 of palmitic acid, 10 to 20 of lauric acid, 20 to 30 of paraffin, 3 to 5 of a carbon nanofiber, expandable graphite and NaCl, wherein the additive amount of the expandable graphite accounts for 12 to 20% of the weight of the paraffin, and the additive amount of NaCl accounts for 3 to 8% of the total weight of the stearic acid, the palmitic acid, the lauric acid and the paraffin. The invention further discloses a preparation method for the phase-change thermal energy-storage material. Compared with the prior art, the prepared phase-change thermal energy-storage material provided by the invention has the advantages of a great potential heat value of phase change, an appropriate phase-change temperature, great thermal energy-storage density, a small volume expansion ratio, stable performance, no toxicity, no pollution, no corrosion to metals, easily available raw materials, easy preparation, etc.

The present invention discloses the composition and preparation process of phase change heat accumulating material. The phase change heat accumulating material consists of crystalline sodium acetate, borax as additive and polyacryamide mainly. The preparation process includes grinding and mixing the said components, heating the mixture to smelting and pouring into packing container; or includes dissolving crystalline sodium acetate, adding borax via stirring, adding polyacryamide via stirring and final pouring into packing container. The phase change heat accumulating material of the present invention has the advantages of great heat accumulating amount, low supercooling degree, proper phase change temperature, no phase separation after long term use, etc.

The invention relates to a boron nitride/pea meal double-heat-conduction-base carbon aerogel. According to the invention, boron nitride, pea meal and a cross-linking agent are used as raw materials, the boron nitride is firstly prepared into modified two-dimensional nano lamellar boron nitride, then the modified two-dimensional nano lamellar boron nitride, the pea meal and the cross-linking agent are subjected to a water bath curing reaction, freeze drying and low-temperature calcination. The preparation method comprises the following steps: 1) preparing modified two-dimensional nano lamellar boron nitride; and (2) preparing the boron nitride/pea meal double-heat-conduction-base carbon aerogel. According to the application of the product as a phase change material, the boron nitride/pea meal double-heat-conduction-base carbon aerogel composite phase change material is obtained by compounding with polyethylene glycol, the phase change temperature is 39-55 DEG C, the phase change latent heat is 168-171J/g, and the heat conductivity coefficient is 0.46-0.58 W/(m.K). The method has the following advantages: 1, the raw materials are low in cost, easy to obtain and environment-friendly; 2, the heat conductivity coefficient is improved by 187%; 2, the leakage problem is avoided; and 3, the phase change latent heat and the thermal stability are high;.

The invention discloses a phase change material applied to a water heater, which is characterized by comprising the following components in percentage by weight: 30-50 of pitch, 50-70 of paraffin, 5-8of graphite and NaCl with the adding content of 3-8 percent of pitch in weight. The invention also discloses a preparation method of the phase change material. Compared with the prior art, the invention has the advantages that the pitch and the graphite mainly play roles of conducting heat and maintaining all the components to be even; the NaCl is used for preventing crystallization, and the paraffin has the effect of storing heat; and the obtained phase change material has the advantages of large phase change potential heat value and heat storage density, proper phase change temperature, small volume expansion ratio, stable performance, no poison and pollution, no corrosion on metal objects, easy acquisition of raw materials, easy manufacture, and the like by the mutual synergetic effectof the four substances.

The invention discloses a room-temperature phase change energy storage medium which is a eutectic mixture composed of water, disodium hydrogen phosphate, sodium silicate and sodium acetate. A preparation method of the phase change energy storage medium comprises the following steps: the components are mixed according to the formula and are heated until completely molten; the mixture is well mixed, and the liquid phase can be used as the phase change energy storage medium. The phase change temperature of phase change energy storage medium is close to room temperature. The phase change energy storage medium also has the advantages of environment-friendly materials, low cost, and the like.

The invention relates to a stable-shape nanocomposite phase change material and a preparation method thereof. The stable-shape nanocomposite phase change material mainly comprises the following components: polyethylene glycol (PEG), acrylamide (AM), clay, an initiator and a catalyst; the components are proportionally added; and a novel nanocomposite phase change material is prepared by an in-situ polymerization method, wherein the PEG is used as a phase change material, and a three-dimensional network composed of polyacrylamide (PAM) and clay serves as a support. The phase change material has relatively high latent heat of phase change, proper phase change temperature, relatively high heat conductivity coefficient and relatively good heat stability. The novel phase change material overcomes the shortcomings of frequent leakage and low heat conductivity coefficient in the phase change of traditional phase change materials; the material can keep a stable shape without encapsulation; and the preparation method is simple while the cost is low. The nanocomposite phase change material is expected to be applied to the fields such as energy-saving materials in buildings, solar energy storage and release and heat-accumulation temperature control clothing.

The invention discloses a heat-insulated constant-temperature plastic profile containing a shape-stabilized phase change material and a production process of the heat-insulated constant-temperature plastic profile. The heat-insulated constant-temperature plastic profile comprises a thermoplastic profile, wherein the thermoplastic profile is uniformly provided with a plurality of concave holes; active carbon on which sodium sulfate is absorbed is arranged in the concave holes; a thermoplastic sheet covering layer is arranged on the thermoplastic profile; and the active carbon on which sodium sulfate is absorbed is covered in the concave holes by the thermoplastic sheet covering layer. The heat-insulated constant-temperature plastic profile has the advantages that sodium sulfate decahydrate is used as the phase change material, and sodium sulfate is proper in phase change temperature, large in latent heat of phase change and low in price; the active carbon is a porous material, and the liquid-phase added pressure of micropores can play roles in sealing and storing phase change liquid; the sizes of heterogeneous points on the walls of the micropores and the sizes of the pores are small, so that the nucleation and crystallization of the sodium sulfate decahydrate can be favorably realized, and then the degree of supercooling of the sodium sulfate decahydrate is reduced; and the active carbon is packaged by using hollow thermoplastics with the concave holes, so that the problem of phase change material leakage is solved, and the shape and size of the material can be adjusted.

The invention discloses a polyimide grafted polyethylene glycol composite solid-solid phase change material. The material mainly comprises polyethylene glycol, polyimide and graphene oxide, wherein amutual cross-linked network structure is formed through the interaction of functional groups and hydrogen bonds among polyethylene glycol, a polyimide precursor and graphene oxide molecules, and thena stable mutual cross-linked skeleton structure is formed through further thermal cross-linking of the polyimide precursor under the inert atmosphere high-temperature condition. The material disclosedby the invention is a stratified structure with cross-linked pores. The preparation method comprises the following steps of 1) preparing a mixed solution of a graphene oxide modified polyimide precursor; 2) and (3) preparing the stratified cross-linked porous structure composite solid-solid phase change material.

The invention discloses a method for preparing composite phase change materials on the basis of polished ceramic tile waste materials. The method includes steps of (1), preparing lauric acid/stearic acid eutectic phase change materials with the phase change temperatures of approximately 30 DEG C; (2), calcining the lauric acid/stearic acid eutectic phase change materials in muffle furnaces to obtain finished porous ceramic powder; (3), pouring the finished porous ceramic powder into hydrochloric acid solution, soaking the finished porous ceramic powder in the hydrochloric acid solution, and stirring the finished porous ceramic powder in the hydrochloric acid solution from time to time until bubble is unavailable; (4), placing activated ceramic powder in modification liquid, placing the modification liquid with the activated ceramic powder into water bath kettles, carrying out oscillation for 10 min, then carrying out suction filtration, sequentially washing the activated ceramic powderby absolute ethyl alcohol and distilled water by 4-5 times and drying the activated ceramic powder at the temperature of 105 DEG C for standby application; (5), weighing modified porous ceramic powder and the lauric acid/stearic acid eutectic phase change materials, heating and melting the modified porous ceramic powder and the lauric acid/stearic acid eutectic phase change materials, sufficiently mixing the modified porous ceramic powder and the lauric acid/stearic acid eutectic phase change materials with one another, further adding cement into the modified porous ceramic powder and the lauric acid/stearic acid eutectic phase change materials, and stirring the cement, the modified porous ceramic powder and the lauric acid/stearic acid eutectic phase change materials to obtain the composite phase change materials. The method has the advantages that processes for preparing the composite phase change materials, composite phase change materials are simple, the method is high in waste material utilization rate, the composite phase change materials have high phase change latent heat, are good in heat stability and have the appropriate phase change temperatures as compared with generalphase change materials, and accordingly the method is high in industrialization ability and has an excellent application prospect.

The invention discloses temperature-sensitive graphene oxide and a preparation method thereof. The preparation method comprises the following steps: 1) uniformly dispersing graphene oxide in a dispersing agent; 2) adding graphene oxide dispersion liquid and a reactive monomer into a reaction container, stirring, introducing inert gas, dropwise adding an initiator, then heating to the temperature of 60-70 DEG C, and stirring until reaction is completed, so that reaction mixed liquor is obtained, wherein the reactive monomer is at least one of n-alkyl methacrylate and n-alkyl acrylate or mixture of the two; 3) precipitating by utilizing an alcohol solvent, then dissolving precipitates into the dispersing agent, centrifuging for removing graphene oxide which is not involved in the reaction, and collecting precipitates II; and 4) dissolving the precipitates II into acetone or ethyl acetate, repeatedly centrifuging, collecting precipitates, and carrying out vacuum drying, so that the temperature-sensitive graphene oxide is obtained. The preparation method disclosed by the invention has the advantages that a phase change material is grafted to the surface of graphene oxide, the temperature-sensitive graphene oxide with stable performance is obtained, and the temperature-sensitive graphene oxide has high phase change enthalpy value and good thermal stability.

The invention discloses a heat-conduction-enhanced ionic liquid composite phase-change heat-storage material based on modified graphene and a preparation method thereof. The preparation method comprises the steps that firstly, covalent functional modification is conducted on graphene oxide through amino-terminated ionic liquid, and the modified graphene oxide reacts with hydrazine hydrate to be reduced, so the dispersity and interfacial compatibility of a graphene filler in an ionic liquid phase-change material matrix are improved, and the heat conduction characteristic of the composite material is improved; and furthermore, the modified graphene is mixed with the imidazolium ionic liquid phase-change material matrix, and conditions such as rotary evaporation and drying are controlled to obtain a mixture of the modified graphene with different loading capacities and the ionic liquid matrix phase-change material. The material provided by the invention has the characteristics of large phase change latent heat and good thermal stability; and meanwhile, the thermal conductivity is increased by 4.4%-127.9% compared with ionic liquid without modified graphene, and the thermal energy storage and conduction characteristics of the material are remarkably improved.

The invention discloses phase-change energy storage ceramsite and a preparation method thereof, relating to the technical field of phase-change energy storage materials. The phase-change energy storage ceramsite contains the following raw materials in parts by weight: 50-70 parts of diatom plate polishing waste, 3-5 parts of quick lime, 20-50 parts of gel materials, 20-30 parts of solid-liquid organic phase-change energy storage materials and 15-40 parts of water. The preparation method comprises the steps of mixing the raw materials in a formula ratio, and carrying out granulation and room-temperature maintenance, so as to obtain the ceramsite. According to the phase-change energy storage ceramsite, the diatom plate polishing waste and the quick lime are taken as the raw materials, the solid-liquid organic phase-change energy storage materials are taken as an energy storage material, the raw materials and the energy storage material are matched with the gel materials so as to generatethe light and high-strength phase-change energy storage ceramsite, so that the application defect of fusion leakage of an organic phase-change material is remedied by virtue of the microstructure advantages and relatively high adsorption capacity of diatom plate polishing powder, and the high-added value functional utilization of the diatom plate polishing waste is realized. By utilizing fire-free and steam-free manners, the pretreatment of the raw materials is omitted, so that the preparation method has the advantages of simple preparation process, low cost, energy saving and environmental protection and the like.

The invention relates to a phase-change cold storage compound and a preparation method thereof. The phase-change cold storage compound comprises sodium sulfate decahydrate, a nucleating agent, a thickening agent and a temperature regulator. Wherein based on 100 parts by mass of the sodium sulfate decahydrate, the mass parts of the nucleating agent, the thickening agent and the temperature regulator are respectively 0.5-5 parts, 0.5-5 parts and 10-20 parts; wherein the phase-change cold storage compound further comprises a carbon nano material, and based on 100 parts by mass of the sodium sulfate decahydrate, the mass part of the carbon nano material is 1-5 parts. By optimizing the formula design of the phase-change cold storage composite material, the composite material has the characteristics of safety, no toxicity, low production cost, small degree of supercooling, high cold storage density and good material stability, and can be applied to use scenes needing 4-8 DEG C, such as a phase-change cold storage system of an air conditioner.