| Traditional organic phase change materials have two inherent defects:easily melting leakage and poor thermal conductivity,which are major obstacles to limit the development and application of traditional organic phase change materials.Carbon aerogels can effectively encapsulate organic phase change materials and provide them with a three-dimensional heat conduction network,so they have received extensive attention and research.However,the existing carbon aerogels also have some shortcomings,such as complex synthesis process,many structural defects,poor mechanical properties and so on.Therefore,in this paper,a new type of polymer hybrid carbon aerogel was assembled through molecular structure design by using the structural advantages of polymer materials.And the organic phase change materials were encapsulated and shaped by using carbon aerogels as the packaging matrix and thermal conductivity reinforced network.Consequently,the composite phase change materials with high performance were prepared,which provides a new method and design idea to solve the problems of organic phase change materials for practical applications.The specific research contents are as follows:(1)Assembly design and performance study of polyimide(PI)/guar gum(GG)hybrid carbon aerogel composite phase change materials:in this study,PI was used as the hard carbon source for the design and assembly of hybrid carbon aerogels,and PI/GG carbide aerogels with regular structure and mechanical stability were prepared with the cooperation of natural biomass GG with long flexible chain.The polyethylene glycol 6000(PEG-6000)package was encapsulated by using the hybrid carbon aerogels as packaging matrix and thermal-conductivitively reinforced network.The effective adsorption capacity of the composite phase change material to the phase change medium was as high as 95 wt%,the latent heat of phase change was 178.5 J/g,the thermal conductivity was increased to 0.71W/m·K,and excellent cycle stability and anti-leakage performance were also exhibited.(2)Assembly design and performance study of guar gum(GG)/diammonium hydrogen phosphate hybrid carbon aerogel composite phase change materials:in order to reduce the production cost and improve the mechanical properties of carbon aerogel,a new type of hybrid carbon aerogel with regular structure,superelasticity,ultra-light and compressible performances was prepared by green process using only biomass GG and diammonium hydrogen phosphate as raw materials.The hybrid carbon aerogel had a density of only 0.458 g/cm~3and can produce 95%deformation under the stress of 0.055MPa.Under the compression ratio of 50%,the hybrid carbon aerogel can still retain 88.1%of its original height after repeated compression for 10 times.The composite phase change materials prepared by using this carbon aerogel as packaging matrix loaded with PEG-6000,showed excellent heat storage and thermal cycling properties,as well as excellent anti-leakage properties.(3)Assembly design and performance study of guar gum(GG)/graphene oxide(GO)/hexagonal boron nitride(h-BN)hybrid carbon aerogel phase change materials:in order to improve the structural stability and thermal conductivity of carbon aerogels,stable and regular carbon aerogels were obtained by synergistic compounding of GG and GO,which were further strengthened by doping with high thermal conductive h-BN.GG/GO/h-BN ternary hybrid carbon aerogels with excellent mechanical properties and thermal conductivity were prepared and compounded with stearic acid(SA)and decanoic acid(CA)binary organic eutectic phase change materials to prepare new binary organic composite phase change materials.The composite phase change materials showed excellent heat storage and thermal cycle properties.The latent heat of the phase change materials can reach 178.5 J/g.After 100 thermal cycles,the thermal conductivity of the composite phase change materials increased to 0.63W/m·K,which was nearly three times than that of SA-CA binary organic eutectic phase change materials... |
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