Mesoporous silica sphere-polysulfone mixed matrix membranes for gas separation.

A series of mixed matrix membranes were prepared comprising polysulfone Udel matrix and ordered mesoporous silica spheres as filler with loadings varying between 0 and 32 wt %. The interaction between the filler and the polymer was studied by scanning and transmission electron microscopy, thermogravimetry, differential scanning calorimetry and dynamic mechanical analyses, N2 porosity, X-ray photoelectron spectrometry, and attenuated total reflectance Fourier transform infrared spectroscopy. All these characterizations allowed us to infer an optimum interaction based on both the penetration of the polymer chains into the mesoporosity of the silica spheres and the establishment of hydrogen bondings between the hydroxyl-rich surface and the aryl ether groups of the polymer. An optimum loading of 8 wt % was found in terms of H2/CH4 separation performance. In addition, the optimum membrane was tested for CO2/N2 separation.