Gas separation using a multilayer thin film composite graphene membrane
Paper ID : 1156-MST2015-FULL
mahdi hedayat1, Javad Karimi-Sabet *2, mohammad sadegh amirzadeh3, Mojtaba Shariaty-Niassarar4
1Transport Phenomena & Nanotech. Lab, University College of Engineering, University of Tehran, Tehran, Iran
2NFCRS, Nuclear Science and Technology Research Institute, Tehran, Iran
3Separation Processes & Nanotech. Lab, Caspian Faculty of Engineering, College of Engineering, University of Tehran, Tehran, Iran
4Transport Phenomena & Nanotech. Lab, University College of Engineering, University of Tehran, Tehran, Iran
Graphene, the 2D allotrope of carbon, among its unique electrical and mechanical properties, proved to be a perfect barrier layer, unless the presence of structural defects in its structure. This makes the graphene an emerging material for using in separation applications. The thin film composite graphene membrane, which is fabricated by successive transferring of large-area graphene layers onto arbitrary substrates, is a new type of membrane which could be used in gas separation and membrane filtration applications. In this work, graphene was synthesized using a low pressure chemical vapor deposition (LPCVD) method on a copper foil served as the catalytic substrate. Raman spectroscopy and optical microscopy reveals that the synthesized graphene is mono-layer and fully covering the substrate surface. The graphene membrane was fabricated by using a direct transfer method. In this method, the graphene covered copper foil was attached to a polymeric porous membrane. After that the copper foil was removed by etching in an ammonium persulfate solution. The ideal selectivity of He to N2 was measured by performing the gas permeation tests using a constant-volume method. The membranes had an ideal selectivity of about knudsen diffusion mechanism with a very high permeances of the order of 10-5 mol/m2.s.Pa. The effect of polymeric substrate characteristics was studied. Also it was revealed that by increasing the number of transferred graphene layers, the gas selectivity will be increased.
Graphene membrane; gas separation; ideal selectivity.
Status : Paper Accepted (Oral Presentation)