石墨烯及氧化石墨烯对分离膜改性的方法、效能和作用机理

Methods,Performances and Mechanisms of Separation Membrane Modified by Graphene and Graphene Oxide

石墨烯及氧化石墨烯由于其独有的性质在分离膜领域引起广泛关注。本文综合分析了石墨烯及氧化石墨烯在分离膜改性方面的几种典型应用,即共混膜、多孔石墨烯膜和层状排列氧化石墨烯膜,并结合其制备方法、效能和作用机理进行阐述。结果表明,相转化法制备的共混膜可以提高膜通量和截留率、增加膜的亲水性并有效抑制膜污染,但是其并不能充分发挥氧化石墨烯独有的结构和性能优势,具有一定的局限性;层薄和机械性能强的完美结合使石墨烯可以通过打孔形成分离性能较好的多孔石墨烯膜,但是制备大片石墨烯的难度和不成熟的打孔技术限制了其进一步发展;而层状排列的氧化石墨烯膜可充分发挥氧化石墨烯材料的特性,以层间间距作为主要运输通道有利于充分发挥氧化石墨烯高输运速率的优点和高选择性的特性,为开创下一代高通量、高选择性、强抗污染性的高性能分离膜提供了重要思路。

Graphene and graphene oxide （GO）have attracted much attention on separation membrane due to their unique properties.In this paper, we review the membrane modification methods by graphene and GO,including membrane blending with GO, nanoporous graphene membrane and layered GO membrane, and comprehensively analyze the performances and mechanisms of these modified membranes.The results show that the blending membrane prepared via the phase inversion method exhibits high water flux, proper solute rejection,excellent hydrophilicity and low fouling propensity, but the unique structure and property of GO does not play effectively in the blending membrane with GO and modified GO nanoporous graphene membrane has good separation performances because of graphene＇ s high mechanical strength, atomic thickness and ability to support subnanometre pores, but it is challenging to manufacture large graphene with maintaining the structural integrity and control the pore size and pore distribution the particular properties of GO get the full play in layered GO membranes, which achieve high water flux mainly because the non-oxidized region of GO with nearly frictionless surface promotes the extremely fast flow of water molecules, and obtains high rejection because of rejecting unwanted solutes.Accordingly, layered GO membrane will be thought as a promising membrane separation technology to obtain fine performances of high permeability, selectivity and anti-fouling ability.