Open AccessSynthesis and Nanofiltration Membrane Performance of Oriented Mesoporous Silica Thin Films on Macroporous Supports
Author(s) -
M. Kaitlyn Clark Wooten,
Venkat R. Koganti,
Shanshan Zhou,
Stephen E. Rankin,
Barbara L. Knutson
Publication year - 2016
Publication title -
acs applied materials and interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.535
H-Index - 228
eISSN - 1944-8252
pISSN - 1944-8244
DOI - 10.1021/acsami.6b06765
Subject(s) - materials science , nanofiltration , membrane , chemical engineering , ethylene glycol , copolymer , mesoporous material , solvent , thin film , mesoporous silica , layer (electronics) , thin film composite membrane , polymer chemistry , polymer , nanotechnology , organic chemistry , composite material , chemistry , biochemistry , catalysis , reverse osmosis , engineering
Silica thin films with accessible hexagonal close-packed (HCP) pores have been deposited on macroporous supports to achieve composite nanofiltration membranes. The properties of these pore channels have been characterized through solvent flux and solute diffusion experiments. A chemically neutral surface (provided by a cross-linked layer of P123 copolymer) for silica thin film synthesis on the alumina macroporous support promotes the alignment of HCP channels vertical to the substrate, where the mesopore templating agent is block copolymer P123 (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)). Vertical pore alignment is achieved for thin films (less than ∼100 nm) on a neutral surface and by sandwiching thicker films (∼240 nm) between two chemically neutral surfaces. Solvent flux through the composite membranes is consistent with accessible 10 nm diameter pores. Size selectivity of the membranes is characterized from the permeability of fluorescently tagged solutes (ranging from 4000 to 70 000 Da), where a size cut off occurs at 69 000 Da for the model protein bovine serum albumin. These permeability studies of the nanofiltration membranes serve to demonstrate solute transport in oriented silica thin film membranes and also highlight their versatility for membrane-based separations.