Effect of ionic liquid structure on viscoelastic behavior of hydrogen-bonded micellar ion gels
Effect of ionic liquid structure on viscoelastic behavior of hydrogen-bonded micellar ion gels
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DOI：
10.1016/j.polymer.2019.121694
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发表时间：
2019-09
期刊：
影响因子：
4.6
通讯作者：
R. Tamate;Kei Hashimoto;Xiang Li;M. Shibayama;M. Watanabe
中科院分区：
文献类型：
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作者：
R. Tamate;Kei Hashimoto;Xiang Li;M. Shibayama;M. Watanabe
基于嵌段共聚物在离子液体中自组装的离子凝胶是一种有吸引力的、可加工的、不挥发的、离子导电的软材料。近年来，一类基于嵌段共聚物胶束间氢键作用的离子凝胶被开发出来，具有良好的机械强度和快速的自修复能力。本文报道了离子液体阳离子和阴离子结构对氢键胶束离子凝胶微观结构和粘弹性能的影响。结果表明，阳离子、阴离子和聚合物链之间的氢键竞争对离子凝胶的粘弹性行为有显著影响。在弱氢键离子液体的情况下，宏观相分离发生由于强氢键之间的二嵌段共聚物胶束，导致在一个不透明的和脆弱的离子凝胶，而存储和损耗模量显着降低离子液体显示强氢键。因此，控制聚合物和离子液体之间的竞争性氢键相互作用对于获得离子凝胶的期望物理性质是至关重要的。
Ion gels based on block copolymer self-assembly in ionic liquids (ILs) are attractive, processable, non-volatile, ion-conducting soft materials. Recently, a new class of ion gels based on hydrogen bonding between jammed block copolymer micelles in ILs that shows good mechanical strength and rapid self-healing ability has been developed. Herein, the effect of IL cation and anion structures on the microstructures and viscoelastic properties of a hydrogen-bonded micellar ion gel is reported. It was clarified that competition among cations, anions, and polymer chains for hydrogen bonding significantly affects the viscoelastic behavior of the ion gel. In the case of weak hydrogen bonding for ILs, macroscopic phase separation occurs due to strong hydrogen bonding between diblock copolymer micelles, resulting in an opaque and fragile ion gel, whereas storage and loss moduli are significantly reduced for ILs showing strong hydrogen bonding. Control of competitive hydrogen bonding interaction between polymers and ILs is thus critical to obtaining the desirable physical properties for ion gels.