Poly(amide-imide)/TiO2 nano-composite gas separation membranes: Fabrication and characterization

Nano-composite membranes based on a fluorinated poly(amide-imide) and TiO2 were fabricated by a sol-gel method. Permeability data for gases such as O-2, N-2, CO2, H-2 and CH4 were collected as a function of pressure and temperature. With the exception of CO2 and H-2, all other gases exhibited higher activation energies for the nano-composite membrane when compared with the pure poly(amide-mide), consistent with the picture of a more rigid or denser structure as suggested by the physical characterization data. The decrease in the activation energy for permeation in the case of CO2 and H-2 has been attributed to specific interactions of these gases with the TiO2 domains. Significant improvements in permselectivies of the poly(amide-imide) membrane have been observed in view of the volume percentage of the TiO2 incorporated into the polymer matrix.