Controlling surface chemistry and mechanical properties of metal ionogels through Lewis acidity and basicity
Controlling surface chemistry and mechanical properties of metal ionogels through Lewis acidity and basicity
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DOI：
10.1039/d0ta11821d
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发表时间：
2021-02-28
影响因子：
11.9
通讯作者：
Hallett, Jason P.
中科院分区：
文献类型：
--
作者：
Clarke, Coby J.;Matthews, Richard P.;Hallett, Jason P.
电离层凝胶是一种软材料，具有显著的物理特性，可以调整以适应应用需求。液体成分-离子液体-是有效的可折叠的，这为利用基于特高压的分析技术探索凝胶表面提供了新的机会。在这里，我们利用离子液体的高溶剂化性质来制造含有高浓度锌的聚乙二醇离子凝胶，然后研究它们的表面，表明可调节性从体延伸到界面。揭示了路易斯酸碱度与金属表面浓度之间的独特关系。化学状态分析和分子动力学表明，Lewis酸性金属模板化聚合物可以提供新的结构，降低脆性并增加柔韧性，而Lewis碱性金属则可以改善聚合物的均匀性并增强凝胶。因此，体积结构，表面组成和金属形态都被发现是密切相关的，并依赖于离子液体阴离子的配位强度。重要的是，金属离子凝胶的高度可控的表面和结构特性允许在广泛的设计空间进行微调，这为基于凝胶的应用提供了新的机会。
Ionogels are emerging as soft materials with remarkable physical properties that can be tuned to suit application requirements. The liquid component-ionic liquids-are effectively involatile, which provides new opportunities to explore gel surfaces with UHV based analytical techniques. Here, we exploit the highly solvating nature of ionic liquids to fabricate poly(ethylene glycol) based ionogels with high concentrations of zinc, and then investigate their surfaces to show that tunability extends beyond the bulk to the interface. A unique relationship between Lewis acidity and basicity and the surface concentration of metal was revealed. Chemical state analysis and molecular dynamics showed that Lewis acidic metals templated polymers to give new architectures reduced brittleness and increased flexibility, while Lewis basic metals improved polymer uniformity and strengthened gels. Therefore, bulk structure, surface composition, and metal speciation were all found to be intimately related and dependent upon the coordination strengths of ionic liquid anions. Importantly, the highly controllable surface and structural properties of metal ionogels allow fine-tuning across a broad design space, which presents new opportunities for gel based applications.