New Insights on the Fast Response of Poly(Ionic Liquid)s to Humidity: The Effect of Free-Ion Concentration
New Insights on the Fast Response of Poly(Ionic Liquid)s to Humidity: The Effect of Free-Ion Concentration
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关于聚离子液体对湿度快速响应的新见解：自由离子浓度的影响
DOI：
10.3390/nano9050749
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发表时间：
2019-05-01
期刊：
影响因子：
5.3
通讯作者：
Duan, Xiaochuan
中科院分区：
文献类型：
--
作者：
Nie, Jianxia;Xiao, Songhua;Duan, Xiaochuan
溶胀机制广泛用于解释离子液体（IL）或聚（离子液体）（PIL）对水分的响应。尽管已经达成了相当广泛的共识，但仍有一些现象没有得到很好的解释。作为对溶胀机制的补充，我们系统地研究了自由体积理论在PIL湿度性能快速响应和恢复中的应用。我们选择聚（1-乙基-3-乙烯基咪唑溴化物）（PIL-Br）、聚（1-乙基-3-乙烯基咪唑四氟硼酸盐）（PIL-BF4）和聚（1-乙基-3-乙烯基咪唑双（三氟甲磺酰亚胺））（PIL-TFSI）作为模型材料，研究了PIL结构（包括阴离子类型、膜厚度和对水分的亲和力）对性能的影响。获得基于自由体积理论的 PIL 湿度传感机制。因此，我们可以将自由体积理论与设计的 PIL 结构及其与水分的亲和力相结合，在 PIL 传感薄膜中获得高浓度的自由离子。此外，由于快速响应和恢复性能，PIL 湿度传感器还随着湿度变化而表现出快速、显着的阻抗变化，可实时监测人体呼吸频率。因此，我们的研究结果为基于自由体积理论理解PIL的湿度性能提供了新的视角，从而通过合理设计PIL传感薄膜实现快速响应和恢复特性。
The swelling mechanism is widely used to explain the response of ionic liquids (ILs) or poly(ionic liquid)s (PILs) to moisture. While a fairly broad consensus has been attained, there are still some phenomena that are not well explained. As a complement to the swelling mechanism, we systematically studied the free volume theory in the rapid response and recovery of PIL humidity performance. We chose poly(1-ethyl-3-vinylimidazolium bromide) (PIL-Br), poly(1-ethyl-3-vinylimidazolium tetrafluoroborate) (PIL-BF4) and poly(1-ethyl-3-vinylimidazolium bis(trifluoromethane sulfonimide)) (PIL-TFSI) as model materials and investigated the impact of PIL structure including anion type, film thickness and affinity to moisture on performance to obtain the humidity sensing mechanism for PILs based on free volume theory. Hence, we can combine free volume theory with the designed PIL structures and their affinity with moisture to obtain a high concentration of free ions in PIL sensing films. Furthermore, the PIL humidity sensors also show fast, substantial impedance changes with changing humidity for real-time monitoring of the human respiratory rate due to a fast response and recovery performance. Therefore, our findings develop a new perspective to understand the humidity performance of PILs based on free volume theory, resulting in fast response and recovery properties realized by the rational design of PIL sensing films.