烷基化氧化石墨烯/正十八烷微胶囊的制备及性能表征

Preparation and characterization of alkylated GO/n-octadecane microcapsules

采用原位聚合法合成了以氧化石墨烯/正十八烷为芯材、三聚氰胺-尿素-甲醛(MUF)树脂为壁材的相变微胶囊。系统研究了氧化石墨烯质量分数对微胶囊的影响,并通过FT-IR、SEM、XRD、DSC和TGA等手段对微胶囊的形貌、结构和热性能进行了分析。结果表明,经正十八烷基异氰酸酯(OI)改性的氧化石墨烯可以在油相中稳定分散,且其热稳定性明显提高。微胶囊呈现规整的球形,粒径约在10~25μm,但当氧化石墨烯加入过量时出现团聚和粘连现象。微胶囊的熔融和结晶过程随着氧化石墨烯的加入而提前,但包覆率和热焓随着氧化石墨烯的增加而减少。氧化石墨质量分数为0.4%时,与纯相变微胶囊相比,导热系数增加了33.7%,说明氧化石墨烯的加入能提高微胶囊的导热性能,加快其热量的输出,提升微胶囊的应用性能。

Phase-change microcapsules are synthesized via in-situ polymerization method with graphene oxide/n-octadecane as core material and melamine-urea-formaldehyde(MUF)polymer as shell material.Influences of the mass fraction of graphene oxide on the microcapsules are studied systematically.The morphology,structure and thermal properties of the microcapsules are analyzed by FT-IR,SEM,XRD,DSC and TGA.Results show that graphene oxide modified by octadecyl isocyanate(OI)can disperse stably in oil phase,and its thermal stability has been obviously improved.The microcapsules show regular spherical shape with particle size in the range of 10-25μm.However,the phenomenon of agglomeration and adhesion will appear if graphene oxide is added excessively.The melting and crystallization processes of the microcapsules advance with the addition of graphene oxide,while the encapsulation and heat enthalpy decrease with the increase of graphene oxide.Compared with pure phase change microcapsules,the thermal conductivity of the prepared microcapsules increases by 33.7%when the addition of graphite oxide is 0.4%,indicating that the addition of graphene oxide can improve the thermal conductivity of microcapsules,accelerate their heat output and improve their application performance.