胺改性纳米多孔蛋白石薄膜中pH值和离子强度控制的阳离子选择性透过

pH- and ionic strength-controlled cation permselectivity in amine-modified nanoporous opal films.

作者信息

Newton Michael R, Bohaty Andrew K, Zhang Yanhui, White Henry S, Zharov Ilya

机构信息

Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.

出版信息

Langmuir. 2006 Apr 25;22(9):4429-32. doi: 10.1021/la053069z.

DOI:10.1021/la053069z

PMID:16618198

Abstract

The influence of pH and ionic strength on permselective transport in nanoporous opal films prepared from 440 nm silica spheres was investigated by cyclic voltammetry in aqueous and acetonitrile solutions. Three-layer opal films were deposited from a 1.5 wt % colloidal solution of silica spheres onto 25-microm-diameter Pt microdisk electrodes shrouded in glass. The films were chemically modified by immersing them in a dry acetonitrile solution of 3-aminopropyl triethoxysilane. When the surface amino groups of the modified opal films are protonated and there is little or no supporting electrolyte present in solution, the flux of cationic redox species through the opal membrane is blocked because of electrostatic repulsion. The permselectivity is pH-dependent and can be modulated by adjusting the Debye screening length within the nanopores of the opal by changing the ionic strength of the contacting solution.

摘要

通过在水溶液和乙腈溶液中进行循环伏安法，研究了pH值和离子强度对由440 nm二氧化硅球体制备的纳米多孔蛋白石薄膜中渗透选择性传输的影响。将三层蛋白石薄膜从1.5 wt%的二氧化硅球胶体溶液沉积到包裹在玻璃中的25微米直径的铂微盘电极上。通过将薄膜浸入3-氨丙基三乙氧基硅烷的干燥乙腈溶液中对其进行化学修饰。当修饰后的蛋白石薄膜表面氨基质子化且溶液中几乎没有或不存在支持电解质时，由于静电排斥，阳离子氧化还原物种通过蛋白石膜的通量被阻断。渗透选择性取决于pH值，并且可以通过改变接触溶液的离子强度来调节蛋白石纳米孔内的德拜屏蔽长度进行调控。