Holding it together: noncovalent cross-linking strategies for ionogels and eutectogels
Holding it together: noncovalent cross-linking strategies for ionogels and eutectogels
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将其结合在一起：离子凝胶和共构凝胶的非共价交联策略
DOI：
10.1039/d2ma00539e
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发表时间：
2022
影响因子：
5
通讯作者：
Panzer, Matthew J.
中科院分区：
文献类型：
--
作者：
Panzer, Matthew J.
当水凝胶根本无法切割它时--要么是因为它干得太快，要么是因为它在电化学设备中应用时不能承受超过大约1伏的电压--精明的材料研究人员该何去何从？这就是两类重要的非水凝胶对应物，称为离子凝胶和共晶凝胶，可以真正发光的地方。用离子液体（IL）或低共熔溶剂（DES）替换水凝胶的含水液相允许实现一系列通用凝胶电解质材料，其提供出色的非挥发性、更宽的电化学稳定性窗口、合理的高离子电导率和几乎无限的化学设计可能性。除了选择特定的IL或DES之外，当涉及到构建将支持离子凝胶或共析凝胶的非水液相的固体、三维、体积跨越网络（或支架）时，还有无数的选择。在这个集中的审查，最近的几种方法来形成这些凝胶使用非共价支架组装和交联检查，并确定主要的非共价相互作用负责（如氢键，疏溶剂性，库仑相互作用）。在非水、离子致密电解质中的非共价支架组装通常导致超分子凝胶材料，其可以在许多情况下表现出极端的拉伸性、良好的韧性和自愈能力。在回顾了最近已经采用的几种策略，用于创建离子凝胶和共晶凝胶，一些激励非共价交联的水凝胶支架报道的简要检查，希望这些可能提供灵感，为未来设计的新型离子凝胶和共晶凝胶的材料研究界。
When a hydrogel simply won’t cut it – either because it dries out too quickly, or it does not tolerate more than roughly one volt when applied in an electrochemical device – where is the savvy materials researcher to turn? This is where two important classes of nonaqueous gel counterparts, known as ionogels and eutectogels, can truly shine. Replacing the aqueous liquid phase of a hydrogel with either an ionic liquid (IL) or a deep eutectic solvent (DES) allows one to realize an array of versatile gel electrolyte materials that offer outstanding nonvolatility, wider windows of electrochemical stability, reasonably high ionic conductivity, and nearly unlimited chemical design possibilities. In addition to choosing a specific IL or DES, there are a myriad of options when it comes to constructing a solid, three-dimensional, volume-spanning network (or scaffold) that will support the nonaqueous liquid phase of an ionogel or eutectogel. In this focused review, several recent approaches to forming these gels using noncovalent scaffold assembly and cross-linking are examined, and the primary noncovalent interactions responsible (e.g. hydrogen bonding, solvophobicity, coulombic interactions) are identified. Noncovalent scaffold assembly in nonaqueous, ion-dense electrolytes often leads to supramolecular gel materials that can exhibit extreme stretchability, good toughness, and an ability to self-heal in many cases. After reviewing several strategies that have been recently employed for creating ionogels and eutectogels, a brief inspection of some motivating noncovalently cross-linked scaffolds reported for hydrogels is presented with the hopes that these may provide inspiration for the future design of novel ionogels and eutectogels by the materials research community.