(354h) Covalent Polymer/Inorganic Hybrids Membranes for Gas

Carbon dioxide (CO2) is one of the main gases which cause global warming, corrosion of natural gas pipelines, and reduction of the combustion efficiency. To overcome these problems, the effective separation of CO₂/N₂ and CO₂/CH₄ has become a necessity. Compared to other separation technologies such as cryogenic techniques, chemical adsorption, and adsorption–separation, membrane separation has evolved as an important CO₂ separation method owing to its low energy consumption, simple operation, low cost, and the absence of a phase transition during the separation process. Polymer membranes, both rubbery and glassy polymers, are regarded as an effective media for gas separation featuring facile preparation, multi-functionality, modularity, etc. Mixed matrix membranes are a type of gas separation membrane that combines both the features of polymer separation and ceramic separation. However, the insufficient distribution, precipitation/phase separation during membrane casting and long-term performance have greatly limited their commercial potential. In this work, a series of polymers, including both rubbery and glass, are covalently grafted from inorganic nanoparticles via surface-initiated atom transfer radical polymerization (SI-ATRP) to make polymer/inorganic hybrids membranes. Due to the covalent immobilization, more free volumes are generated, together with membrane uniformity and suppression of detrimental phase separation. The synthesized materials were characterized by FTIR, NMR, XRD, DSC, GPC and tensile test. The selectivity of the membrane was thoroughly examined.