凯发

Graphene is a well-known two-dimensional material that exhibits preeminent electrical, mechanical and thermal properties owing to its unique one-atom-thick structure. Graphene and its derivatives (e.g., graphene oxide) have become emerging nano-building blocks for separation membranes featuring distinct laminar structures and tunable physicochemical properties. Extraordinary molecular separation properties for purifying water and gases have been demonstrated by graphene-based membranes, which have attracted a huge surge of interest during the past few years.

However, most of the graphene-based membranes are polymeric supported or free-standing. The mechanical strength and thermal and chemical stability of these supports are main obstacles for the practical application of graphene-based membranes. To address this problem, a facile silane-graft modification approach proposed by our group was demonstrated to be an efficient way to improve the quality of the GO film formed on the porous ceramic substrate. Based on this, we further demonstrated a scalable fabrication of GO membranes on ceramic hollow fiber substrate and showed good PV dehydrotion of aqueous organic solution. The as-prepared membrane exhibited excellent water permeation for dimethyl carbonate/water mixtures. In addition, we also proposed a novel type of membrane with fast and selective gas-transport channels of GO laminates enabled by polymer-GO hydrogen bonding. Featuring molecular-sieving interlayer spaces and straight diffusion pathways, the assembled graphene oxide laminates endow the gas separation membranes with excellent CO2 permeation performance and extraordinary operational stability which is believed to be attractive for implementation in practical CO2 capture. Recently, we demonstrated a novel bio-inspired strategy that utilizes the synergistic effect of a hydrophilic polymer and GO laminates to realize fast water-transport channels for constructing high-efficiency membrane.

Because GO nanosheets can be easily mass-produced by chemical oxidization and ultrasonic exfoliation from inexpensive raw graphite, it is expected that GO-based material is promising for membrane based process, including PV dehydration and gas separation. Meanwhile, our ceramic-supported technique endows GO membranes greater potential for future practical separation applications.