Enhanced Separation Performance for CO2 Gas of Mixed-Matrix Membranes Incorporated with TiO2/Graphene Oxide: Synergistic Effect of Graphene Oxide and Small TiO2 Particles on Gas Permeability of Membranes

This study combines the adsorption layer nanoreactor synthesis (ALRS) method with in situ polymerization to prepare high-performance separation hybrid membranes containing TiO2-graphene oxide (TiO2-GO). TiO2 nanoparticles were initially generated on the GO surface through ALRS. Hybrid membranes containing A-TiO2-GO were then prepared using in situ polymerization. The inhibition of aggregation by the strong combination between the small TiO2 particles and the GO surface led to a homogeneous distribution of TiO2-GO in the polymeric matrix. This, in turn, caused a significant improvement of the membranes performance for CO2 separation. Both the small TiO2 particles and GO played an important role in increasing the gas separation performance of membranes. In particular, TiO2 small particles, with a polar surface, promoted the CO2 diffusion through the membranes, while GO addition significantly increased the solubility selectivity of the membranes toward CO2.