文献类型：期刊文献

英文题名：Mechanism of electrical percolation of w/o microemulsions formed by nonionic surfactants

作者：Wang, Fang[1,2];Fang, Bo[1];Zhang, Zhiqing[2];Zhang, Saiyu[1]

机构：[1]E China Univ Sci & Technol, Res Ctr Chem Engn, Shanghai 200237, Peoples R China;[2]China Univ Petr, Coll Chem & Chem Engn, Dongying, Peoples R China

年份：2008

卷号：29

期号：8

起止页码：1166

外文期刊名：JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY

收录：;EI(收录号：20083611519454);WOS:【SCI-EXPANDED(收录号:WOS:000258621700024)】；

基金：This project was granted financial support from China Post-doctoral Science Foundation (20060400629).

语种：英文

外文关键词：electrical percolation; hydration of polar headgroups; microemulsion; nonionic surfactant

摘要：A study was carried out on the mechanism of electrical conductivity percolation of H2O/C16EO20/n-butanol/heptane microemulsions. Electrical conductivity, UV-vis spectroscopy and FTIR spectra were used to study the diluted dry microemulsions with the mass ratio of C16EO20/n-butanol/heptane=3:3:4. The results of electrical conductivity showed that the percolation occurred around phi(w)=20wt% and the transition of w/o microemulsions to bicontinueous microemulsions happened when phi(w)=45wt%. From the UV-vis absorption spectra, it was found that the absorption of methyl orange (MO) in microemulsions shifted red than that of in oil phase, but the maximal absorption peak (lambda(max)) remained unchanged when phi(w)>20wt%. It implied that the position of MO solubilized in microemulsions was unvaried after free water appeared in the core. FTIR spectra revealed that the OH band of water in microemulsions moved to high frequency at low phi(w) (20wt%) and became broader at high phi(w). It indicated that the added water only caused the hydration of EO at low phi(w), the hydration completed when phi(w)>20wt% and then the residual water entered into the core with properties similar to bulk water. The presence of free water as ions exchange medium will cause the electrical conductance increased. The percolation appeared after the hydration of EO completed.