Microphase Separation in Neutral Homopolymer Blends Induced by Salt-Doping
Microphase Separation in Neutral Homopolymer Blends Induced by Salt-Doping
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DOI：
10.1021/acs.macromol.2c02198
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发表时间：
2022-09
期刊：
影响因子：
5.5
通讯作者：
Xian Kong;Jian Qin
中科院分区：
文献类型：
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作者：
Xian Kong;Jian Qin
聚合物体系中的微相分离提供了一种自下而上的策略来制造纳米结构。据报道发生微相分离的聚合物通常包括嵌段共聚物或聚电解质。中性均聚物，这是比较容易合成，被认为是不能微相分离。在这里，使用一个最小的模型，占离子溶剂化，我们表明，微相分离是可能的中性均聚物共混物具有足够的介电对比度，在微量的盐掺杂。微相分离的驱动力是选择性的离子溶剂化，这将更小的离子在域具有较高的介电常数，和局部电荷中性的倾向，以减少静电能之间的竞争。折衷的办法是使微相分离和离子选择性溶剂化的出现长度。影响这种竞争的因素进行了探讨，包括离子溶剂化半径，介电对比度，和聚合物分数，这指向观察这种行为的实验方向。这些研究结果表明，低成本和简便的替代品，以产生微相分离，可利用先进的材料设计和制备。
Microphase separation in polymeric systems provides a bottom-up strategy to fabricate nanostructures. Polymers that are reported to undergo microphase separation usually include block copolymers or polyelectrolytes. Neutral homopolymers, which are comparatively easy to synthesize, are thought to be incapable of microphase separation. Here, using a minimal model that accounts for ion solvation, we show that microphase separation is possible in neutral homopolymer blends with sufficient dielectric contrast, upon a tiny amount of salt-doping. The driving force for the microphase separation is the competition between selective ion solvation, which places smaller ions in domains with higher dielectric constant, and the propensity for local charge neutrality to decrease the electrostatic energy. The compromise is an emergent length over which microphase separation occurs and ions are selectively solvated. The factors affecting such competitions are explored, including ion solvation radii, dielectric contrast, and polymer fraction, which point to directions for observing this behavior experimentally. These findings suggest a low-cost and facile alternative to produce microphase separation which may be exploited in advanced material design and preparation.