Collapse of polyelectrolyte networks induced by their interaction with an oppositely charged surfactant. Theory
Collapse of polyelectrolyte networks induced by their interaction with an oppositely charged surfactant. Theory
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聚电解质网络因与带相反电荷的表面活性剂相互作用而崩溃。
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
S. G. Starodubtzev
中科院分区：
文献类型：
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作者：
A. Khokhlov;E. Kramarenko;E. Makhaeva;S. G. Starodubtzev
本文提出了一个在带相反电荷的表面活性剂溶液中弱电荷的双金属网络的膨胀和坍塌的简单理论。考虑到以下贡献的自由能：自由能的体积相互作用和弹性变形的网络链，自由能与胶束形成和自由能的平移运动的所有移动的离子在系统中（平移熵）。带电表面活性剂的溶液和带电和中性表面活性剂组分的混合溶液的情况都已考虑在内。它已被证明，网络的行为取决于系统中的总表面活性剂浓度，并对应于以下三个制度之一：在低浓度下，胶束内的网络不形成和聚合物网络的行为是类似的网络溶胀在溶液中的低分子量盐（制度1）。在第二种状态下，网络内的表面活性剂浓度超过临界胶束浓度，形成胶束;在这种状态下，网络崩溃，因为聚集在胶束中的表面活性剂分子停止在网络样品中产生“施加”渗透压。在第三个政权，在非常高的表面活性剂浓度，形成额外的胶束内的网络停止，和网络尺寸与相应的中性网络相一致。
A very simple theory of swelling and collapse of weakly charged polyelectrolyte networks in the solution of an oppositely charged surfactant has been developed. The following contributions to the free energy were taken into account: free energy of volume interaction and of elastic deformation of the network chains, free energy connected with micelle formation and free energy of translational motion of all mobile ions in the system (translational entropy). Both the cases of a solution of charged surfactant and that of a mixed solution of charged and neutral surfactant components have been taken into account. It has been shown that the behaviour of the network depends on the total surfactant concentration in the system and corresponds to one of the three following regimes: At low concentration, micelles inside the network are not formed and the behaviour of the polymer network is similar to that of a network swelling in the solution of a lowmolecular-weight salt (regime 1). In the second regime, surfactant concentration inside the network exceeds the critical micelle concentration and micelles are formed; in this regime the network collapses because surfactant molecules, aggregated in micelles, cease to create “exerting” osmotic pressure in the network sample. In the third regime, at very high surfactant concentration, formation of additional micelles inside the network ceases, and the network dimensions coincide with those of the corresponding neutral network.