(387a) Ultrathin Graphene Oxide-Based Membrane for Separation of Small Organic Molecules

Separation of small organic molecules with similar sizes and close boiling points, for example, by distillation, is an extremely energy intensive process in the industry. Microporous membranes may provide a new opportunity to realize energy-efficient separation of these small organic molecules. However, it is a grand challenge to fabricate high quality, molecular-sieving membranes that have uniform pores between 0.4 and 0.8 nm, size of many small hydrocarbon molecules, and are also stable under organic environment. To address this challenge, we have developed a stable, tunable graphene oxide membrane which is chemically modified using molecular layer deposition. Liquid phase pressure driven permeation of aliphatic hydrocarbons whose size difference is less than 3 Å has shown ideal selectivity of over 50 through this membrane. This membrane has shown appreciable separation of straight chain hydrocarbons from its mixture with branched hydrocarbon indicating its possible application for extracting unreacted linear hydrocarbons after catalytic isomerization reaction in the petroleum processing industry.