MICELLES OF POLYSOAPS
MICELLES OF POLYSOAPS
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DOI：
10.1021/la00008a012
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发表时间：
1995-08-01
期刊：
影响因子：
3.9
通讯作者：
HALPERIN, A
中科院分区：
文献类型：
--
作者：
BORISOV, OV;HALPERIN, A
聚皂是一种含有两亲单体的亲水聚合物，可以形成链内胶束。对于高盐、稀溶液的极限，分析了链内胶束的结构、聚皂的构型及其在游离两亲性存在下的改性。重要的聚合参数是连接相邻表面活性剂的间隔链的聚合度n，以及整个链的聚合度n。球形链内胶束的结构类似于自由胶束的结构，直到n接近10。当n较大时，由于间隔链聚集时形成的环的拥挤，聚集数降低。当n接近400或更高时，链内胶束作用可能被抑制。链内聚集大大降低了链的尺寸。当m小于或等于单胶束的平衡聚集数p(Eq)时，链的尺寸为单胶束的尺寸。在相反的情况下，热介质有利的构型是分支结构的构型。一旦超过临界缔合浓度(CAC)，自由表面活性剂的加入会导致混合胶束的形成。CAC通常比自由胶束的CMC小得多。当达到确定的饱和浓度时，混合胶束的形成就结束了。此时，链完全展开，结合的混合胶束的结构基本上是自由胶束的结构。当聚合的表面活性剂倾向于形成柱状胶束时，链内胶束的形状可以随n和自由两亲分子的浓度而变化。
Polysoaps, hydrophilic polymers incorporating m amphiphilic monomers, can form intrachain micelles. The structure of the intrachain micelles, the configurations of the polysoaps, and their modification in the presence of free amphiphiles are analyzed for the high salt, dilute solution limit. The important polymeric parameters are the polymerization degree of the spacer chains joining adjacent surfactants, n, and of the chain as a whole, N. The structure of spherical intrachain micelles is similar to that of free micelles up to n approximate to 10. For larger n the aggregation number decreases because of the crowding of the loops formed upon aggregation by the spacer chains. For n approximate to 400 and above the intrachain micellization may be repressed. The chain dimensions are greatly reduced by the intrachain aggregation. When m less than or equal to p(eq), the equilibrium aggregation number of a single micelle, the chain dimensions are those of a single micelle. In the opposite case the thermodinamically favored configuration is that of a branched structure. The addition of free surfactants results in the formation of mixed micelles once the critical association concentration (cac) is exceeded. The cac is typically much smaller than the cmc of free micelles. The formation of mixed micelles ends when a well-defined saturation concentration is attained. At this point the chain is fully unfolded and the structure of the bound, mixed micelles is essentially that of free micelles. When the polymerized surfactants tend to form cylindrical micelles, the shape of the intrachain micelles can vary with n and with the concentration of free amphiphiles.