Membrane boost for water desalination

According to study leader Yu Han, a professor of chemistry at KAUST (King Abdullah University of Science and Technology), water desalination membranes should simultaneously exhibit high water flux and high salt rejection.

Carbon nanomaterials are expected to meet these requirements due to their unique surface chemistry and propensity to stack into channels with diameters smaller than one nanometre, but channel alignment and stacking difficulties make their large-scale use in membranes challenging.

“One way to address these limitations is through two-dimensional porous carbonaceous membranes with regular and uniformly distributed subnanometre-sized molecular transport channels,” said first author Jie Shen, a postdoc in Han’s group.

These membranes are typically synthesised in solution, which promotes the random growth of a disordered three-dimensional structure with poorly defined micropores.

Yu Han, Vincent Tung, Ingo Pinnau and former KAUST scientist Lance Li, who is now at the University of Hong Kong, have developed a method that helps control the growth of two-dimensional conjugated polymer frameworks into ultrathin carbon films using chemical vapour deposition.