Soluble complexes from poly(ethylene oxide)-block-polymethacrylate anions and N-alkylpyridinium cations
Soluble complexes from poly(ethylene oxide)-block-polymethacrylate anions and N-alkylpyridinium cations
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DOI：
10.1021/ma970197o
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发表时间：
1997-06-16
期刊：
影响因子：
5.5
通讯作者：
Eisenberg, A
中科院分区：
文献类型：
--
作者：
Bronich, TK;Kabanov, AV;Eisenberg, A
聚（环氧乙烷）-b-聚（甲基丙烯酸钠）（PEO-b-PMANa）和N-烷基吡啶溴化物的复合物是水溶性的，与聚（甲基丙烯酸钠）的那些形成鲜明对比。这些系统进行了研究，使用电位滴定，微量热法，zeta电位测量，光散射和电子显微镜。当混合物的组成（Z = [C_（16）PyBr]/[COO-]）变化时，PEO-b-PMANa与溴化十六烷基吡啶（C_（16）PyBr）形成的络合物有三个区域（A-C）。(A)在Z < 1时，C16 PyBr与聚离子静电结合以形成具有负ζ电位的可溶性复合物。(B)复合物的尺寸减小并达到最小（o.d. 67 nm）。这些化学计量配合物是可溶的和稳定的。它们似乎是胶束与C16 PyBr中和的聚离子链和PEO链的壳形成的核心。(C)随着Z的进一步增加，表面活性剂阳离子结合在颗粒中（zeta > 0）。在饱和浓度的C16 PyBr下形成的颗粒是球形的，并且显著地单分散。总的来说，这些系统代表了一类新的亲液胶体，其表现出两亲性嵌段共聚物和聚电解质-表面活性剂复合物的组合性质。
Complexes from poly(ethylene oxide)-b-poly(sodium methacrylate) (PEO-b-PMANa) and N-alkylpyridinium bromides are water soluble, in marked contrast to those from poly(sodium methacrylate). These systems are studied using potentiometric titration, microcalorimetry, zeta-potential measurement, light scattering and electron microscopy. Three regions (A-C) are observed with a complex from PEO-b-PMANa and cetylpyridinuim bromide (C16PyBr) when the composition of the mixture (Z = [C16PyBr]/[COO-]) is varied. (A) At Z < 1 C16PyBr binds electrostatically to the polyion to form soluble complex with a negative zeta-potential. (B) The size of the complex decreases and reaches minimum (o.d. 67 nm) at Z = 1 when zeta = 0. Those stoichiometric complexes are soluble and stable. They appear to be micelles with a core formed by C16PyBr neutralized polyion chains and a shell of PEO chains. (C) With a further increase in Z, the surfactant cations incorporate in the particles (zeta > 0). The particles formed at saturating concentrations of C16PyBr are spherical and remarkably monodisperse. Overall, these systems represent a new class of lyophilic colloids that exhibit combined properties of amphiphilic block copolymers and polyelectrolyte-surfactant complexes.