乳化工艺对石蜡/SiO_2复合相变材料结构和性能的影响

Influences of emulsification process on the paraffin composite phase change materials with silicon dioxide shell

在水溶液中,以正硅酸乙酯为硅源,以溶胶-凝胶法制备了两种石蜡/SiO2复合相变材料,采用FT-IR、XRD、SEM、DSC和TG对其结构、储热及稳定性能进行了表征,研究了乳化工艺对复合材料结构和性能的影响。结果表明,采用乳化法和反相乳化法均可得到石蜡与SiO2简单嵌合且结构稳定的石蜡/SiO2复合相变材料,其石蜡包覆量分别为47.45%和61.88%,熔化潜热分别为78.73和101.98J/g,凝固潜热分别为77.14和101.28J/g。后者具有更好的储热和热稳定性能。

Paraffin/SiO2 composite phase change material was prepared by sol-gel in which paraffin as phase change material,SiO2 as carrier,water as solvent.The impact of the emulsification process was discussed. Fourier transformation infrared spectrometer (FT-IR),X-ray diffractometer (XRD)and scanning electronic mi-croscope (SEM)were used to determine chemical structure,crystalloid phase and microstructure of microen-capsulated paraffin composites with SiO2 shell,respectively.The thermal properties and thermal stability were investigated by the differential scanning calorimeter (DSC)and thermo gravimetric analyzer (TG).The results showed that the composites had structural stability in different emulsification process.The maximum microen-capsulation ratio of microcapsules was prepared by emulsification and reversed phase emulsification were 47.45% and 61.88% respectively.The melting latent heats of them were measured as 78.73 and 101.98 J/g. The freezing latent heats of them were 7 7 .1 4 and 1 0 1 .2 8 J/g.