Tunable Coacervation of Well-Defined Homologous Polyanions and Polycations by Local Polarity
Tunable Coacervation of Well-Defined Homologous Polyanions and Polycations by Local Polarity
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DOI：
10.1021/acscentsci.8b00964
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发表时间：
2019-03-27
影响因子：
18.2
通讯作者：
Xia, Yan
中科院分区：
文献类型：
--
作者：
Lou, Junzhe;Friedowitz, Sean;Xia, Yan
聚电解质的离子络合是许多重要生物过程和技术应用的重要机制。络合的主要驱动力是静电，这是已知的电荷中心附近的局部极性的影响，但聚电解质的络合的影响仍然很少探索。我们开发了一系列同源的定义明确的聚电解质具有相同的骨架结构，控制分子量，和可调的局部极性，以调节附近的带电基团的溶剂化环境。通过荧光标记的聚阳离子的聚合物浓度的光谱测量，获得了大量的系统的，准确的相图。这些相图明确地表明，在较宽的分子量范围内，在降低局部极性的情况下，液体状凝聚对盐的加入更稳定。这些趋势被定量捕获的理论，结合分散相互作用，电荷连接，和可逆的离子结合的影响，提供微观设计规则，调整分子参数和局部极性的络合。
The ionic complexation of polyelectrolytes is an important mechanism underlying many important biological processes and technical applications. The main driving force for complexation is electrostatic, which is known to be affected by the local polarity near charge centers, but the impact of which on the complexation of polyelectrolytes remains poorly explored. We developed a homologous series of well-defined polyelectrolytes with identical backbone structures, controlled molecular weights, and tunable local polarity to modulate the solvation environment near charged groups. A multitude of systematic, accurate phase diagrams were obtained by spectroscopic measurements of polymer concentrations via fluorescent labeling of polycations. These phase diagrams unambiguously revealed that the liquidlike coacervation is more stable against salt addition at reduced local polarity over a wide range of molecular weights. These trends were quantitatively captured by a theory of complexation that incorporates the effects of dispersion interactions, charge connectivity, and reversible ion-binding, providing the microscopic design rules for tuning molecular parameters and local polarity.