RATIONAL DESIGN AND SYNTHESIS OF NOVEL HYBRID CARBON MEMBRANE WITH CONTROLLED POROSITY VIA CARBON-METAL COMPOSITE

摘要

Nanostructured carbon materials have attracted tremendous attention for their possible applications as membranes, catalyst supports, and electrode materials. Particularly, membranes made from carbon (CMS) have been extensively studied owing to their excellent performance for gas molecules separation [1]. A significant advantage of the carbon membranes is that they can perform the separation of small molecules under harsh conditions such as corrosive environment, elevated temperature and pressure. Simultaneously, the carbon membranes have a molecular sieving capability rendered by nanoporous with dimensions near the size of the permeating gas molecules, which help it can achieve a desirable and practicable flux and selectivity. Up to date, the carbon membranes are typically produced from inert or vacuum pyrolysis of thermosetting polymers such as poly (furfuryl alcohol) [2], phenolic resins [3] and polyimide (PI) [4]. Though great progresses have been made in carbon membranes, it is uncommon that a strong trade-off relationship exists between the permeability and the selectivity, that is, the permeation flux though the carbon membranes is considerably reduced with increased gas selectivity due to the disordered pore structure and diffusion resistance in membranes. Herein, we report nanostructured carbon/titanium dioxide composite membranes by incorporating titanium dioxide using a sol-gel method, and the composite membranes showed an excellent performance for small gas molecules separation. These mixed-matrix membrane materials allow for preservation of selectivity while showing significantly increased permeability.