Mixed Conductive Soft Solids by Electrostatically Driven Network Formation of a Conjugated Polyelectrolyte
Mixed Conductive Soft Solids by Electrostatically Driven Network Formation of a Conjugated Polyelectrolyte
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DOI：
10.1021/acs.chemmater.7b05303
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发表时间：
2018-02-27
影响因子：
8.6
通讯作者：
Segalman, Rachel A.
中科院分区：
文献类型：
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作者：
Danielsen, Scott P. O.;Sanoja, Gabriel E.;Segalman, Rachel A.
共轭聚电解质(聚[2，6-(4，4-双钾butanylsulfonate-4H-cydopenta-[2，1-b；3，4-b‘]-dithiophene)-alt-4，7-(2，1，3-benzothiadiazole)]，PCPDTBT-SO3K)])组装成一种新颖的分级水凝胶结构，所有结构证据表明主要是静电作用，而不是芳香族或介元相互作用。PCPDTBT-SO3K形成缠绕的聚合物网络，其中聚合物链通过离子交联剂连接在一起，包括渗透形成宏观三维网络的微凝胶簇。随着温度的升高，离子获得了向微凝胶团簇外部移动的迁移率，溶解了离子交联键，并通过静电斥力抑制了网络渗透。虽然pi-pi堆积相互作用可能以一种无序的方式存在，但在X射线散射中没有明显的远程pi-pi堆积。基于PCPDTBT-SO3K的软材料保持半导性，在结构重组温度下表现出较高的离子电导率。
A conjugated polyelectrolyte (poly[2,6-(4,4-bis-potassium butanylsulfonate-4H-cydopenta-[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)], PCPDTBT-SO3K) assembles into a novel, hierarchical hydrogel structure with all structural evidence indicating dominant electrostatic rather than aromatic or mesogen interactions. PCPDTBT-SO3K forms an entangled polymer mesh, where polymer chains are tied together by ionic cross-links, comprising microgel clusters that percolate to form a macroscopic three-dimensional network. With increasing temperature, ions gain mobility to move toward the exterior of the microgel clusters, dissolving the ionic cross-links and inhibiting network percolation through electrostatic repulsion. While pi-pi stacking interactions may be present in a disorganized fashion, no long-range pi-pi stacking is evident in X-ray scattering. Soft materials based on PCPDTBT-SO3K remain semiconducting and exhibit elevated ionic conductivity at the structural reorganization temperature.