Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening.
Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening.
复制标题
DOI：
10.1038/nmat4880
复制
发表时间：
2017-06
期刊：
影响因子：
41.2
通讯作者：
Siria A
中科院分区：
文献类型：
--
作者：
Comtet J;Niguès A;Kaiser V;Coasne B;Bocquet L;Siria A
室温离子液体（RTIL）是一种新型的储能和主动润滑材料。它们是独特的液体，挑战了电解质的经典框架，其在带电界面的行为仍然难以捉摸，与其电化学活性相关的奇异响应。通过基于音叉的AFM纳米流变学测量，我们在这里探索的性质限制RTIL，揭示了一个戏剧性的变化RTIL对一个固体样相低于阈值厚度，指向毛细管冻结限制。这个阈值与限制材料的金属性质有关，更多的金属表面有利于冻结。这是解释在冻结过渡的移位，考虑到电子屏蔽的影响RTIL润湿的限制表面。我们的研究结果提供了新的观点，其性质的限制RTIL与纳米多孔金属结构内的性质的影响，并建议应用程序调整纳米级润滑与相变RTIL，通过改变基板的性质和图案，和主动极化的应用。
Room temperature Ionic liquids (RTIL) are new materials with fundamental importance for energy storage and active lubrication. They are unsual liquids, which challenge the classical frameworks of electrolytes, whose behavior at electrified interfaces remains elusive with exotic responses relevant to their electrochemical activity. By means of tuning fork based AFM nanorheological measurements, we explore here the properties of confined RTIL, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This is interpreted in terms of the shift of freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures and suggests applications to tune nanoscale lubrication with phase-changing RTIL, by varying the nature and patterning of the substrate, and application of active polarisation.