title: Ultrathin Silica Membranes with Highly Ordered and Perpendicular Nanochannels for Precise and Fast Molecular Separation.
abstract: Membranes with the ability of molecular/ionic separation offer potential in many processes ranging from molecular purification/sensing, to nanofluidics and to mimicking biological membranes. In this work, we report the preparation of a perforative free-standing ultrathin silica membrane consisting of straight and parallel nanochannels with a uniform size (∼2.3 nm) for precise and fast molecular separation. Due to its small and uniform channel size, the membrane exhibits a precise selectivity toward molecules based on size and charge, which can be tuned by ionic strength, pH or surface modification. Furthermore, the ultrasmall thickness (10-120 nm), vertically aligned channels, and high porosity (4.0 × 10(12) pores cm(-2)) give rise to a significantly high molecular transport rate. In addition, the membrane also displays excellent stability and can be consecutively reused for a month after washing or calcination. More importantly, the membrane fabrication is convenient, inexpensive, and does not rely on sophisticated facilities or conditions, providing potential applications in both separation science and micro/nanofluidic chip technologies.
authors.affiliation: Institute of Microanalytical Systems, Department of Chemistry & Centre for Chemistry of High-Performance and Novel Materials, Zhejiang University , Hangzhou 310058, P. R. China.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Lin
authors.affiliation: Institute of Microanalytical Systems, Department of Chemistry & Centre for Chemistry of High-Performance and Novel Materials, Zhejiang University , Hangzhou 310058, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Institute of Microanalytical Systems, Department of Chemistry & Centre for Chemistry of High-Performance and Novel Materials, Zhejiang University , Hangzhou 310058, P. R. China.
authors.forename: Longhua
authors.initials: L
authors.lastname: Ding
authors.affiliation: Institute of Microanalytical Systems, Department of Chemistry & Centre for Chemistry of High-Performance and Novel Materials, Zhejiang University , Hangzhou 310058, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Su
keywords: ion transport; molecular separation; nanochannel; silica; ultrathin membrane