Micelles and Gels of Mixed Triblock Copoly(Oxyalkylene)s in Aqueous Solution

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• 作者：Wayne J. Harrison ; Gamal J. Aboulgasem ; Fathi A. I. Elathrem ; S. Keith Nixon ; David Attwood ; Colin Price ; and Colin Booth
• 刊名：Langmuir
• 出版年：2005
• 出版时间：July 5, 2005
• 年：2005
• 卷：21
• 期：14
• 页码：6170 - 6178
• 全文大小：180K
• 年卷期：v.21,no.14(July 5, 2005)
• ISSN：1520-5827

文摘

The micellization in dilute aqueous solution of a 50/50 wt% mixture of two triblock copolymers, E₄₅B₁₄E₄₅and E₆₂P₃₉E₆₂, and the gelation of concentrated micellar solutions have been investigated over a rangeof temperatures. Here E, B, and P denote oxyethylene, oxubutylene, and oxypropylene chain units.Comparison is made with aqueous solutions of the individual copolymers. The results of light scatteringmeasurements are consistent with effectively separate micellization of the two copolymers in the mixture.Hard gel formed when the extent of micellization was high for both copolymers. Because of the relativelyhigh critical micellization temperatures of copolymer E₆₂P₃₉E₆₂, the low-temperature boundary of the hardgel was high for this copolymer and for the mixture. The minimum concentration for hard-gel formationwas higher for the mixture than for either of the individual copolymers, as would be expected for packingof two distributions of micelles of different average size.