油酸单乙醇酰胺聚氧乙烯醚微乳液体系的研究

Study on the Microemulsion System of Oleic Acid Monoethanolamide Polyoxyethylene Ether

以油酸单乙醇酰胺聚氧乙烯醚作为乳化剂制备水包油型微乳液。通过拟三元相图、粒径大小及粒径分布确定较优配方:复配表面活性剂(由油酸单乙醇酰胺聚氧乙烯醚和吐温20组成)的亲水亲油平衡值(HLB值)为15,助表面活性剂为正丁醇,复配表面活性剂与助表面活性剂的质量比(K;值)为1,混合表面活性剂与正辛烷的质量比(S/O值)=1∶1,水添加量70%。此时该微乳体系平均粒径为18.6nm,多分散指数(PDI值)为0.206。当微乳体系含水量大于70%时,可形成水包油型微乳液。透射电镜照片显示,此时微乳液滴分布均匀,呈球形。较优配方的微乳液具有良好的离心稳定性和耐高温性。

Oleic acid monoethanolamide polyoxyethylene ether was used as emulsifier to prepare oil-in-water type microemulsion.The optimal formula was determined through the pseudo-three-phase diagram,the particle size and its distribution of the microemulsion.The results showed that the optimal microemulsion formula are as follows:the hydrophilic-lipophilic balance value(value of HLB)of the compound surfactant(composed of oleic acid monoethanolamide polyoxyethylene ether and Tween 20)is 15,cosurfactant was n-butanol,the mass ratio of compound surfactant and co-surfactant(value of K;)is 1,the mass ratio of mixed surfactants to n-octane(value of S/O)is 1∶1,and water content is 70%.The average particle size of O/W-type microemulsion system is 18.6 nm,and the polydispersity index(value of PDI)is 0.206.When the water content is greater than 70%,the system could form an O/W type microemulsion.Microstructure of microemulsion was photographed by transmission electron microscopy.It showed that the microemulsion droplets is uniformly distributed and spherical in shape.The microemulsion of the optimal formula has good centrifugal stability and high temperature resistance.