title: Sequential Vapor Infiltration Treatment Enhances the Ionic Current Rectification Performance of Composite Membranes Based on Mesoporous Silica Confined in Anodic Alumina.
abstract: Ionic current rectification of nanofluidic diode membranes has been studied widely in recent years because it is analogous to the functionality of biological ion channels in principle. We report a new method to fabricate ionic current rectification membranes based on mesoporous silica confined in anodic aluminum oxide (AAO) membranes. Two types of mesostructured silica nanocomposites, hexagonal structure and nanoparticle stacked structure, were used to asymmetrically fill nanochannels of AAO membranes by a vapor-phase synthesis (VPS) method with aspiration approach and were further modified via sequence vapor infiltration (SVI) treatment. The ionic current measurements indicated that SVI treatment can modulate the asymmetric ionic transport in prepared membranes, which exhibited clear ionic current rectification phenomenon under optimal conditions. The ionic current rectifying behavior is derived from the asymmetry of surface conformations, silica species components, and hydrophobic wettability, which are created by the asymmetrical filling type, silica depositions on the heterogeneous membranes, and the condensation of silanol groups. This article provides a considerable strategy to fabricate composite membranes with obvious ionic current rectification performance via the cooperation of the VPS method and SVI treatment and opens up the potential of mesoporous silica confined in AAO membranes to mimic fluid transport in biological processes.
authors.affiliation: Beijing Key Laboratory of Materials for Energy Conversion and Storage, BNU Key Laboratory of Environmentally Friendly and Functional Polymer Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Beijing Key Laboratory of Materials for Energy Conversion and Storage, BNU Key Laboratory of Environmentally Friendly and Functional Polymer Materials, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China.
authors.forename: Zhengping
authors.identifier: 0000-0002-7944-2455
authors.initials: Z
authors.lastname: Liu