School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
Science. 2014 Feb 14;343(6172):752-4. doi: 10.1126/science.1245711.
Graphene-based materials can have well-defined nanometer pores and can exhibit low frictional water flow inside them, making their properties of interest for filtration and separation. We investigate permeation through micrometer-thick laminates prepared by means of vacuum filtration of graphene oxide suspensions. The laminates are vacuum-tight in the dry state but, if immersed in water, act as molecular sieves, blocking all solutes with hydrated radii larger than 4.5 angstroms. Smaller ions permeate through the membranes at rates thousands of times faster than what is expected for simple diffusion. We believe that this behavior is caused by a network of nanocapillaries that open up in the hydrated state and accept only species that fit in. The anomalously fast permeation is attributed to a capillary-like high pressure acting on ions inside graphene capillaries.
基于石墨烯的材料具有良好定义的纳米孔，并且在其内部表现出低摩擦的水流，这使得它们在过滤和分离方面具有吸引力。我们研究了通过真空过滤氧化石墨烯悬浮液制备的微米厚层压板的渗透。层压板在干燥状态下是完全密封的，但是，如果浸入水中，则作为分子筛，阻止所有水合半径大于 4.5 埃的溶质。较小的离子以比简单扩散所预期的快数千倍的速率通过膜渗透。我们认为这种行为是由水合状态下打开的纳米毛细管网络引起的，只接受适合的物质。异常快速的渗透归因于作用在石墨烯毛细管内离子上的类似于毛细管的高压。
