乳液模板法制备新型pH响应微胶囊材料的研究

Study on preparation of novel pH-responsive microcapsule materials by emulsion-templated method

利用乳液模板法制备了新型微胶囊材料。以小麦水解蛋白为稳定剂,水为外相、辛癸酸甘油酯为内相,制备了水包油型Pickering乳液。通过显微镜和粒径统计表征了乳液的微观结构,稳定剂质量分数为1%、2%、3%、4%和5%的Pickering乳液平均液滴直径分别为96.8μm、78.2μm、62.31μm、47.6μm和38.7μm。加入戊二醛与蛋白的氨基发生席夫碱反应,交联界面相形成微胶囊,通过红外光谱、显微镜和EDS Mapping证实了微胶囊的形成。戊二醛浓度为5%、10%、20%、30%、40%和50%时,微胶囊产率分别为75.9%、52.9%、35.3%、41.7%、39.0%和38.2%。由于席夫碱的亚胺基团具有pH响应性,可在酸性条件下断裂,故而该微胶囊具有pH响应性,能够在1mol/L盐酸环境下发生结构破裂,达到控制释放内部包封的油溶性组分的目的。

A novel microcapsule material was prepared by emulsion-templated method.The oil-in-water Pickering emulsions were prepared using wheat hydrolyzed protein as the stabilizer,water as the external phase and glycerol octanedioate as the internal phase.The microstructure of the emulsions was characterized by microscopy and particle size statistics,and the average droplet diameters of Pickering emulsions with stabilizer mass fractions of 1%,2%,3%,4%and 5%were 96.8μm,78.2μm,62.31μm,47.6μm and 38.7μm,respectively.The formation of microcapsules was confirmed by FT-IR,microscopy and EDS mapping,as the Schiff base reaction of glutaraldehyde with the amino group of the protein cross-linked the interfacial phase to form microcapsules.The microcapsule yields were 77.6%,53.8%,37.5%,41.3%,39.6%and 36.2%for glutaraldehyde concentrations of 5%,10%,20%,30%,40%and 50%,respectively.Since the pH-responsive imine group of Schiff base could be broken under acidic conditions,the pH-responsive microcapsules could undergo structural rupture under 1mol/L HCl to achieve controlled release of the internally encapsulated oil-soluble components.