Filtration of water and organic solutions plays an important role for applications such as water purification. Graphene oxide (GO) membranes are known for their mechanical robustness, making them attractive for molecular separation and filtration applications. However, nanofiltration through GO membranes is limited to aqueous solutions because organic solvents cannot permeate GO membranes.
Rahul Raveendran Nair, University of Manchester, UK, and colleagues have developed highly laminated GO (HLGO) membranes that are thin enough to permit the fast permeation by both water and organic solvents. The exceptionally thin GO laminates (as thin as 8 nm) are made from randomly stacked 10-20 µm large GO flakes. Due to the random stacking of the GO flakes, the thin layers contain pinholes between the flakes that allow solvent permeation.
The team performed filtration experiments using dye-containing methanol solutions. More than 99.9 % of the dye molecules were rejected, showing the potential of HLGO membranes for organic solvent filtration.
- Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation,
Q. Yang, Y. Su, C. Chi, C. T. Cherian, K. Huang, V. G. Kravets, F. C. Wang, J. C. Zhang, A. Pratt, A. N. Grigorenko, F. Guinea, A. K. Geim, R. R. Nair,
Nat. Mater. 2017, 16, 1198–1202.