title: Facile Synthesis of Robust Free-Standing TiO2Nanotubular Membranes for Biofiltration Applications.
abstract: Robust monodisperse nanoporous membranes have a wide range of biotechnological applications, but are often difficult or costly to fabricate. Here, a simple technique is reported to produce free-standing TiO2nanotubular membranes with through-hole morphology. It consists in a 3-step anodization procedure carried out at room temperature on a Ti foil. The first anodization (1 h at 80 V) is used to pattern the surface of the metallic foil. Then, the second anodization (24 h at 80 V) produces the array of TiO2nanotubes that will constitute the final membrane. A higher voltage anodization (3-5 minutes at 180 V) is finally applied to detach the TiO2nanotubular layer from the underlying Ti foil. In order to completely remove the barrier layer that obstructs some pores of the membrane, the latter is etched 2 minutes in a buffered oxide etch solution. The overall process produces 60 μm-thick TiO2nanotubular membranes with tube openings of 110 nm on one side and 73 nm on the other side. The through-hole morphology of these membranes has been verified by performing diffusion experiments with glucose, insulin and immunoglobulin G where in differences in diffusion rate are observed based on molecular weight. Such biocompatible TiO2nanotubular membranes, with controlled pore size and morphology, have broad biotechnological and biomedical applications.
authors.affiliation: Therapeutic Micro and Nanotechnology Laboratory, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), 1700 4 Street, Box 2520, San Francisco, CA, 94158, USA.
authors.forename: Julien
authors.initials: J
authors.lastname: Schweicher
authors.affiliation: Therapeutic Micro and Nanotechnology Laboratory, Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco (UCSF), 1700 4 Street, Box 2520, San Francisco, CA, 94158, USA.
authors.forename: Tejal A
authors.initials: TA
authors.lastname: Desai
keywords: Biofiltration; Diffusion of Biomolecules; Membranes; Multi-Step Anodization; TiO2 Nanotubes