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以石墨烯/正十八烷为芯材,三聚氰胺-尿素-甲醛树脂(MUF)为壁材,苯乙烯马来酸酐共聚物(SMA)为乳化剂,采用乳液聚合法制备相变微胶囊.系统研究了石墨烯对于正十八烷微胶囊性能的影响.采用场发射扫描电子显微镜(FE-SEM)、傅里叶变换红外光谱分析仪(FTIR)、拉曼光谱仪、X射线衍射仪(XRD)、Hot Disk热常数分析仪、示差扫描量热仪(DSC)和热重分析仪(TGA)对相变微胶囊的外貌形态、晶型结构和热性能进行表征和分析.结果表明,微胶囊呈圆球形且光滑,粒径约为1~30μm.当石墨烯添加量为0.1 g时,微胶囊的形貌无明显变化.当加入过量石墨烯时,微胶囊出现了明显的团聚现象.XRD测试表明,包覆于微胶囊中的石墨烯没有使微胶囊的结晶峰位置发生明显的偏移,这对于微胶囊的实际应用是有利的.微胶囊的相变热焓和包覆率随着石墨烯的加入而不断减小,但芯材的过冷现象得到了明显的改善.石墨烯对于微胶囊传热性能的提升有着显著的效果.当石墨烯的添加量为0.2 g时,微胶囊的导热系数为0.092 W·m-1·K-1,与纯微胶囊相比提高了约51%,这说明石墨烯改善了传统相变微胶囊的传热性能,提升了相变微胶囊的应用性能.
The phase change microcapsules were prepared by emulsion polymerization using graphene / n-octadecane as core material, melamine-urea-formaldehyde resin (MUF) as wall material and styrene-maleic anhydride copolymer as emulsifier. The effects of graphene on the properties of n-octadecane microcapsules were investigated by means of field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction , Hot Disk thermal analyzer, differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA) were used to characterize and analyze the morphology, crystal structure and thermal properties of phase-change microcapsules. Spherical and smooth, particle size of about 1 ~ 30μm.When the graphene addition amount of 0.1 g, the morphology of the microcapsules no significant change.When adding excessive graphene, the microcapsules showed a significant agglomeration.XRD test It is shown that the graphene encapsulated in the microcapsules does not significantly shift the crystal peak position of the microcapsules, which is beneficial for the practical application of the microcapsules.Hydration enthalpies and coating rates of the microcapsules vary with the graphite The addition of ene decreases continuously, but the cooling of the core material is clear Graphene has a significant effect on the heat transfer performance of microcapsules.When the graphene addition is 0.2 g, the thermal conductivity of the microcapsules is 0.092 W · m-1 · K-1, Compared with about 51%, which shows that graphene improves the heat transfer performance of traditional phase change microcapsules and enhances the application performance of phase change microcapsules.