Physical Design, Preparation and Functionalization of Carbon Membranes for Gas Separation

Two challenges faced by carbon membrane for application on commercial scale are its low permeability and poor mechanical strength. And it is attributed to the vermiform pore structures and special characteristics of carbon membranes. In order to solve these problems, methods such as choosing the precursors with suitable chemical structure and space mould, incorporating nano-size functional groups into precursors are employed to effectively change and improve the vermiform pore structures of carbon membranes and enhance the gas permeabilities of carbon membranes. The results indicate that the gas permeabilities of hybridized function carbon membranes are increased by 2 orders in magnitude without reducing the gas selectivity obviously. Besides, some functional carbon membranes have also revealed higher gas selectivity for some gases such as CO(2). The coal-based composite carbon membranes with high gas permselectivity are developed by dip-coating the precursors on the cheap coal-based supports invented by ourselves to improve the mechanical strength of carbon membranes.