Influence of Imogolite Nanotubes on the Structure and Performance of PVA and Psf Nanocomposite Membranes

Presentation Title: Influence of imogolite nanotubes on the structure and performance of PVA and PSf nanocomposite membranes.

Authors: Ming Li and Jonathan Brant

Abstract: Engineered nanomaterials, imogolite nanotubes, have been used to improve the mechanical strength and performance (flux and selectivity) of membranes used in desalination processes. Enhanced flux is purported to result from water transport through nanotubes because of their unique geometry and chemical properties. Though promising results have been obtained with carbon nanotubes, these materials are not without their drawbacks, namely cost, clumping and poor loading in polymer films. The structures and chemical properties of imogolite nanotubes are highly desirable for to further the application of nanocomposite membranes. Our presentation will cover the relationships between imogolite nanotube properties, namely length, throat diameter, and surface (inner and outer) functionalities, on water flux and ion rejection. Membrane performance is evaluated using pressure-driven filtration and thermaly-driven configurations with an emphasis on treating high-salinity waters (TDS > 50,000 ppm), representative of oil and gas produced waters. Membranes are synthesized using the following base polymers: poly (vinyl alcohol) (PVA) and polysulfone (PSf). Nanotube dispersion will be evaluated in these two polymers and the resulting impacts of these variables on membrane performance. The change of membrane robustness and surface chemistry by adding imogolite nanotubes will also be discussed.