Membranes for gas separation have developed significantly in the last twenty years

however

there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability. Our study examines the fundamental properties of polyetherketone (PEK

a thermally stable and chemically resistant polymer) membranes prepared using concentrated sulphuric acid (98% H2SO4) as the solvent. Non-solvents used in the work included acetic acid

ethanol

methanol

glycerol

and water. The concentration of the polymer solutions was chosen to be 20%. The membrane structures were examined using SEM

and the gas separation properties were measured using a lab-scale test rig. The results show that formation and control of membrane structures are complicated

and many preparation parameters affect membrane morphology and performance. Using appropriate conditions skinned sponge-like structured hollow fiber membranes could be made from PEK by using acetic acid as the internal coagulant. PEK hollow fibers spun from 20%PEK/H2SO4 solutions with 50% aqueous acetic acid as internal coagulant had selectivity for hydrogen/methane of around 40

implying a solution diffusion separation mechanism for gas separation without the need for fiber coating or after post-treatments.