Modified TiO2 nanoparticles were successfully embedded into Pebax-1657 as a polymer matrix. The resulting mixed-matrix membranes are highly efficient for CO2 removal especially at high pressures. Nanofiller grafting with 3-aminopropyl-diethoxymethylsilane (silane agent) and surface modification with carboxymethyl chitosan led to Pebax-modified-TiO2 composite membranes with 50–60% increase in CO2 permeability and 30–33% in CO2/N2 selectivity compared to the pristine Pebax. The performance of the nanocomposite membranes is favorably above the 2008 Robeson upper bound. Stability analyses of the prepared membranes showed acceptable durability of the membranes in permeation experiments. Characterization techniques such as FT-IR, DSC, TGA, and SEM showed the compatibility of the nanoparticles and the polymer, better thermal stability of the nanocomposite membranes, and satisfactory dispersion of nanofillers into the polymer
