离子液体孔封闭对半孔微粒内的溶液扩散的影响
Andrew D Drake1, Yuxin He1, Folami Ladipo2
1Department of Chemical and Materials Engineering, University of Kentucky, 177 F.P. Anderson Tower, Lexington, Kentucky 40506-0046, United States.
The journal of physical chemistry. B
|March 13, 2024
概括
离子液体被封闭在二氧化孔中显著减缓了运输速度,而孔壁相互作用比孔径更为关键. 水含量和毛孔表面的变化进一步影响扩散率.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 纳米技术 纳米技术
背景情况:
- 离子液体 (ILs) 具有独特的特性,使其适合各种应用.
- 在纳米孔状材料中被限制可以改变IL的行为.
- 了解封闭IL的运输特性对于优化其性能至关重要.
研究的目的:
- 为了研究1 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 甲基氧化 ([BMIM][PF6]) 局限于二氧化微粒中的运输特性.
- 为了确定孔径大小和表面化学对IL扩散的影响.
- 阐明毛孔壁相互作用与毛孔大小在分子运输中的作用.
主要方法:
- 使用中性 (DCM) 和阴性 (罗达胺6G) 探针进行光漂白 (FRAP) 后光恢复的共聚焦显微镜.
- 差分扫描热度计 (DSC) 和富里叶变换红外光谱 (FTIR) 来确认IL的限制.
- 孔径大小 (5.4和9纳米) 的系统变化和表面变化 (疏水性,水化).
主要成果:
- 在9纳米孔中DCM的扩散度比在散装IL中低2个数量级.
- 孔径大小 (5.4 与 9 nm 相比) 并没有显著影响未经修改的二氧化中的DCM扩散性.
- 阴离子探针扩散比中性探针扩散低63%.
- 增加的水含量提高了DCM的扩散率37%.
- 疏水性表面修饰 (绑定甲基化) 将DCM的扩散率提高了3倍.
- 随后与PF6进行的离子交换,与裸体相比,扩散率降低了一半.
结论:
- 毛孔壁相互作用,而不是毛孔大小,是影响纳米封闭ILs扩散的主要因素.
- 可以使用表面修改策略来调整IL运输特性.
- 了解孔壁效应对于设计纳米封闭IL用于分离,催化和能量储存的应用至关重要.
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