Preparation and Characterization of Polyetherketone Hollow Fibre Membranes for Gas Separation

摘要

Hollow fibre membrances for gas separation have been spun from polyetherketone (PEK), using a dry-jet wet spinning proedure, and a range of hollow fibre morphologies have been produced. The general morphology of PEK hollow fibres could be described in terms of five zones: a thin denser outer skin, an interconnected outer macro-voided layer, a cnetral sponge pore structure, an inner macro-voided layer, and an inner skin. The effects of some essential spinning parameters, i.e. air gap, water injection rate, and internal coagulatn composition, have been investigated with respect to fibre morphology and gas permeation characteristics. As-spun PEK hollow fibre membranes show high hydrogen, carbon dioxide, and methane permeation rates, and low gas selectivity, which is characteristic of microporous membranes that undergo Knudsen diffusion. Silicone-coated fibres give higher separation factors but lower permeation rates, due to a change form Knudsen diffusion to be mroe selective solution-diffusion mechanism of permeation.