Chemical modification of polysulphone: 2. Gas and liquid permeability of polysulphone/polydimethylsiloxane graft copolymer membranes

Abstract The gas and liquid permeabilities of polysulphone/polydimethylsiloxane (PSF/PDMS) graft copolymer membranes have been investigated. The permeability coefficients to nitrogen, oxygen, hydrogen, methane and carbon dioxide were evaluated. The gas permeability coefficients of the graft copolymer membranes were influenced by the PDMS content of the graft copolymer. In the region of >60wt% PDMS content, the oxygen permeability coefficient of PSF/PDMS graft copolymer membrane was (1−3) × 10 −8 cm 3 cm cm −2 s −1 cmHg −1 . In addition, the permeability to methane and carbon dioxide was remarkably enhanced in comparison with PSF membrane. The introduction of PDMS chains greatly increased the diffusion coefficients of methane and carbon dioxide. In the case of pervaporation of aqueous ethanol solution, the preferential permeation of ethanol was observed through the graft copolymer membrane for which the PDMS content was >50wt%.