纳米甲壳素基Pickering乳液辅助构筑相变微胶囊

Fabrication of phase change microcapsules via nano-chitin stabilized Pickering emulsion

相变微胶囊可以通过增加传热面积和防止泄漏来提高相变材料的热性能和机械性能。本文首先通过一种简单、高效的方法制备了纳米甲壳素,然后利用纳米甲壳素稳定石蜡制备Pickering乳液,最后通过乳液模板法得到相变微胶囊。文章着重研究了盐酸汽蒸甲壳素的时间,纳米甲壳素悬浮液的质量分数,核壳比等变量对微胶囊表面形貌和粒径的影响,实验结果表明,当汽蒸时间为5 h,纳米甲壳素悬浮液质量分数为0.5%,核壳比为3∶1时,所制得的相变微胶囊粒径为29.6μm,其熔融焓高达187.4 J/g,包覆率为71.6%。通过热重分析和加热/冷却循环测试对相变微胶囊的热稳定性和热循环性能进行表征,结果表明微胶囊具有良好的热循环稳定性。

Phase change microcapsules can enhance the thermal and mechanical performance of phase change materials used in thermal energy storage by increasing the heat transfer area and preventing the leakage of materials. In this paper, nano-chitin was prepared by a simple and efficient method, and then a Pickering emulsion was prepared by stabilizing paraffin with the nano-chitin. Finally, phase change microcapsules were obtained by emulsion template method. The effects of hydrochloric acid steaming time, nano-chitin suspension concentration and core-shell ratio on the surface morphology and particle size of microcapsules were studied. The results showed that, when the steaming time was 5 h, the concentration of nano-chitin suspension was 0.5%, and the core-shell ratio was 3∶1, the particle size of the microcapsules obtained was 29.6 μm and the melting enthalpy was up to 187.4 J/g, correspondingly indicative of an encapsulation rate of 71.6%. The thermal stability and thermal cycling performance of microcapsules were characterized by thermogravimetric analysis and heating/cooling cycle, showing a good thermal cycling stability.