Effect of Silica Nanoparticles on the Performance of Polysulfone Membranes for Olefin-Paraffin Separation

The separations of ethylene/ethane and propylene/propane using polysulfone-silica nanocomposite membranes were studied. Silica nanoparticles were prepared via sol-gel method and the membranes by phase inversion. Characterization by Fourier transform spectroscopy and scanning electron microscopy indicated a good distribution of silica nanoparticles in the polymer matrix and also a good compatibility between the two phases. The performances of the prepared membranes in ethylene-ethane and propylene-propane separation were evaluated. The results showed the increments in gas permeability and selectivity by silica. Higher silica contents increased the solubility coefficient and reduced the diffusion coefficient of gases. The plasticization pressure of polysulfone was increased by incorporating the silica nanoparticles in polymer.