Influence of “Hydrophobicity” on the Composition and Dynamics of Polyelectrolyte Complex Coacervates
Influence of “Hydrophobicity” on the Composition and Dynamics of Polyelectrolyte Complex Coacervates
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DOI：
10.1021/acs.macromol.2c00267
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发表时间：
2022-08
期刊：
影响因子：
5.5
通讯作者：
Mo Yang;Swapnil L. Sonawane;Zachary A. Digby;Jin G. Park;J. Schlenoff
中科院分区：
文献类型：
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作者：
Mo Yang;Swapnil L. Sonawane;Zachary A. Digby;Jin G. Park;J. Schlenoff
各种类型的特定的相互作用被认为是补充的主要熵驱动力负责自发的液-液相分离的混合物中带相反电荷的聚电解质。在这些相互作用中，疏水性最近已经通过合成和复合物形成的聚电解质轴承疏水侧基或骨干实验探测。在这项工作中，聚（4-乙烯基吡啶），P4 VP，是N-烷基化的链从1到6个碳的长度。将完全烷基化的聚阳离子与聚（甲基丙烯酸钠）络合，以产生双金属络合物或凝聚物（佩奇）。与直觉相反，用N-甲基至N-丁基P4 VP制备的佩奇对盐的添加不稳定，烷烃链越长，越容易掺杂并且具有较低的溶解临界盐浓度。相反，这些佩奇的线性粘弹性响应变化不大。掺杂和性能的转变，观察与N-戊基和N-己基链，后者具有更高的模量和盐浓度的敏感性低得多。小角X射线散射表明，一个新的形态的N-戊基和N-己基P4 VP佩奇，与相互作用/相分离烷烃链提供了一个过渡到疏水性为主的佩奇。
Various types of specific interactions are believed to supplement the major entropic driving forces responsible for spontaneous liquid–liquid phase separations in mixtures of oppositely charged polyelectrolytes. Among these interactions, hydrophobicity has recently been probed experimentally via the synthesis and complex formation of polyelectrolytes bearing hydrophobic pendant groups or backbones. In this work, poly(4-vinylpyridines), P4VP, wereN-alkylated with chains from one to six carbons in length. The fully alkylated polycations were complexed with poly(sodium methacrylate) to yield polyelectrolyte complexes or coacervates (PECs). Counterintuitively, PECs made withN-methyl toN-butyl P4VP werelessstable to the addition of salt the longer the alkane chain, being easier to dope and having a lower critical salt concentration for dissolution. In contrast, the linear viscoelastic response of these PECs varied little. A transition in doping and properties was observed withN-pentyl andN-hexyl chains, the latter having a much higher modulus and much less sensitivity to salt concentration. Small-angle X-ray scattering suggested a new morphology for theN-pentyl andN-hexyl P4VP PECs, with interacting/phase separating alkane chains providing a transition into hydrophobicity-dominated PECs.