Effect of Hydrophobically Modified Polymer on Salt-Induced Structural Transition in Microemulsions

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• 作者：Xiaojing Ma ; Xiaoyong Wang ; Jinben Wang ; Donghong Guo ; Yilin Wang ; Jianping Ye ; Zhengping Wang ; and Haike Yan
• 刊名：Langmuir
• 出版年：2004
• 出版时间：July 6, 2004
• 年：2004
• 卷：20
• 期：14
• 页码：5679 - 5682
• 全文大小：58K
• 年卷期：v.20,no.14(July 6, 2004)
• ISSN：1520-5827

文摘

The phase boundaries of the middle-phase microemulsion for NaCl/SDS/H₂O/1-heptane/1-pentanolsystems in the absence of polymer and in the presence of unmodified poly(acrylamide) (PAM) andhydrophobically modified poly(acrylamide) (HMPAM) have been determined at varying salt concentrations.These three middle-phase microemulsions (with HMPAM, with PAM, and without polymer) were studiedusing interfacial tension measurement, steady-state fluorescence, and time-resolved fluorescence quenching.Compared to the polymer-free system and the system with PAM, the addition of HMPAM significantlyenlarges the range of the salt concentrations for the formation of the middle-phase microemulison andcauses both the excess oil and aqueous phases to increase in volume at the expense of the middle-phasemicroemulsion. For the middle-phase microemulsion with HMPAM, the interfacial tensions of themicroemulsion phase with the excess oil phase and with the excess aqueous phase are all ultralow andexhibit higher values than those with PAM and without polymer. At the same salt concentration, theapparent surfactant aggregation number in the middle-phase microemulsion with HMPAM has the smallestvalue among these three systems. All results indicate that the strong interaction of surfactant withhydrophobically modified polymer has a large effect on the formation and properties of the middle-phasemicroemulsion.