title: Synthesis and Nanofiltration Membrane Performance of Oriented Mesoporous Silica Thin Films on Macroporous Supports.
abstract: 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.
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky 177 F. Paul Anderson Tower, Lexington, Kentucky 40506-0046, United States.
authors.forename: M Kaitlyn
authors.initials: MK
authors.lastname: Clark Wooten
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky 177 F. Paul Anderson Tower, Lexington, Kentucky 40506-0046, United States.
authors.forename: Venkat R
authors.initials: VR
authors.lastname: Koganti
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky 177 F. Paul Anderson Tower, Lexington, Kentucky 40506-0046, United States.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky 177 F. Paul Anderson Tower, Lexington, Kentucky 40506-0046, United States.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Rankin
authors.affiliation: Department of Chemical and Materials Engineering, University of Kentucky 177 F. Paul Anderson Tower, Lexington, Kentucky 40506-0046, United States.
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Knutson
keywords: ceramic membranes; mesoporous silica; oriented pores; self-assembly; size selective