| Phase change material (PCM) is a new type of environmental material for saving energy, which has the advantages of larger latent heats, higher storage density, and approximate isothermal to the phase transition, etc. It is helpful to develop new renewable energy and improve energy efficiency.Currently,low temperature solid-liquid PCM has a better prospect for industrialization. To avoid the leakage of liquid PCM during applications, packaging materials are neeessary for the encapsulation of solid-liquid PCM. Thus related studies of various shape-stabilized phase change material are a hot spot.This paper presents the methods of physical adsorption and solid state reaction at low temperature respectively on preparing the shape-stabilized phase change materials, which solute the leaked problems of phase change materials liquid phase caused in transporting and using process by encapsulation of solid-liquid PCM.The microporous silica composite microspheres made of silicon dioxide and organic compounds were synthesised by hydrolysis and condensation of tetraethoxysilane (TEOS) using dodecylamine as porogen and hexadecy ltrimethyl ammonium bromide as dispersant. And then the SiO2 porous microspheres were prepared by drying and roasting the composite to remove organic compounds. The porous SiO2 microspheres were characterized with FT-IR,XRD,ESEM and N2 adsorption-desorption. The results show that particle size of porous microspheres is uniform. The specific surface area is 1013.8cm2/g, and the pore structure is mainly mesoporous within 10nm. Therefore the structure of porous microspheres will be helpful for adsorption and encapsulation of PCM.The TiO2/SiO2 composite microspheres with microporous core/mesoporous shell structure were prepared by hydrolysis of tetrabutyl titanate in the presence of the uncalcined silica microspheres using dodecylamine as porogen. The porous TiO2/SiO2 microspheres were characterized with FT-IR,XRD,ESEM and N2 adsorption-desorption. The results show that the Ti-O-Si characteristic peak at 960cm-1 is found in FT-IR spectrum of composite TiO2/SiO2 micropheres. The pore size distribution of porous microspheres with uniform size is wide, and the specific surface area is 320.6cm2/g. The microspheres exist in a lot of "the ink bottle" shape holes, which will be helpful for adsorption of PCM. The lowest eutectic mixtures of laurel acid-palmitic acid (LA-PA) and hexadecanoic acid- palmitic acid (HD-PA) were prepared by the Schroeder principle and specific experiments. The shape-stabilized composite phase change materials (LA-PA/SiO2, LA-PA/TiO2/SiO2, HD-PA/SiO2 and HD-PA/TiO2/SiO2 ) were prepared by the physical infiltration method using the eutectic mixture as phase change material, the porous SiO2 microspheres or TiO2/SiO2 composite microspheres as skeleton. The structure and properties of the composite phase change material were studied by FT-IR, ESEM, DSC and the test of melting and solidification process. The results show that the composite material maintains a good morphology, higher phase change enthalpies and lower phase change temperatures.The latent heat and melting temperature of LA-PA/SiO2, LA-PA/TiO2/SiO2, HD-PA/SiO2 and HD-PA/TiO2/SiO2 are 84.06J.g-1, 34.36℃; 72.41 J.g-1, 48.49℃; 72.37J.g-1, 45.53℃; 75.74J.g-1,44.59℃respectively. Compeared with eutectic mixtures, heat transfer performance of the composites also has been improved.The shape-stabilized phase change material with SiO2 sketch were prepared by low heating solid state reaction using the eutectic mixtures as phase change body materials and sodium silicate as raw materials. The structure, morphology, and thermal performance of the composite were characterized by FT-IR, ESEM, DSC and the test of melting and solidification process. The results show that phase change enthalpies and temperatures of LA-PA/SiO2 and HD-PA/SiO2 were 97.35J.g-1, 52.71℃; 102.35J.g-1, 53.69℃respectively. Fothermore, compeared with eutectic mixtures, the melting temperature of the shape-stabilized phase change material increases.
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