Gelation bath composition Permeance (GPUa) Selectivity CO2 N2 CO2/CH4 0 vol.% DMAC, 100 vol. wt% deionized water 21.5 0.49 43.88 40 vol. % DMAC, 60 vol. % deionized water 10.25 0.34 30.15 80 vol.% DMAC, 20 vol. wt% deionized water 5.01 0.25 20.04 90 vol.% DMAC, 10 vol. wt% deionized water 2.90 0.20 14.50 Temperature: 25°C, feed pressure: 10 bar aGPU = 10−6 cm3 (STP) / (cm3 s cmHg)

Table 2: Gas permeance and CO2/N2 selectivity of PDMS/PSf composite membranes (different gelation bath composition).