Development of thin-film composite membranes for carbon dioxide and methane separation using sulfonated poly(phenylene oxide)

Novel membranes based on sulfonated poly (phenylene oxide) (SPPO) was devel oped. SPPO membranes in the hydrogen form were converted to metal ion forms . The effect of exchange with metal ions including monovalent (Li+, Na+, K), divalent (Mg2+, Ba2+, Ca2+) and trivalent (Al3+) ions was investigated i n terms of permeation rate and permeation rate ratios for CO2 and CH4 gases . Both dense homogeneous membranes and thin-film composite (TFC) membranes were studied for their gas separation characteristics. The effect of membra ne preparation conditions and operating parameters on the membrane performa nce were also investigated. The selectivity of the TFC membrane increased a s the cationic charge density increased as a result of electrostatic cross- linking. TFC membrane of very high selectivity was achieved by coating a th in layer of SPPO-Mg on a PES substrate. (C) 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 735-742, 2000.