Solvent selection for manufacture of fluorinated polyimide composite membranes Original Research Article

Polysulfone (PSf) and five fluorinated polyimides were tested for their solubility with 24 organics or their mixtures in order to select a solvent suitable for developing a composite membrane consisting of an inexpensive substrate with an expensive selective layer of high-performance fluorinated polyimides for CO2/CH4 separation. The experimental results show that only nitromethane can dissolve 6F-Durene and 6F Durene-mPDA but not dissolve PSf. The manufacture of a 6F-Durene composite membrane using PSf as a substrate was attempted with the dip-coating method, which has not been previously reported. The PSf/6F-Durene composite membrane after repair with silicon rubber was defect free. There is a potential to manufacture a defect-free fluorinated polyimide composite hollow-fiber membrane.