Polyamide-based membranes consisting of nanocomposite interlayers for high performance nanofiltration

It is still a task to synthesize polyamide-based membranes with selective layers down to 10–20 nm for high performance desalination. Herein, cellulose nanocrystals (CNC) were used as one-dimensional (1D) nanorods and graphene oxides (GO) as two-dimensional (2D) nanosheets, respectively, to construct nanocomposite interlayers for synthesizing polyamide layers thinner than 15 nm. The 2D nanosheets are homogeneously mixed with the 1D nanorods and effectively reduce the surface roughness of the nanocomposite interlayers with decreasing the mass ratio of CNC/GO. Polyamide layers with a thickness of 10–15 nm have been synthesized at an ultralow monomer concentration of 0.025 wt% on these CNC/GO nanocomposite interlayers. The polyamide-based membranes exhibit extremely high water permeation (45.9 L/m 2 ·h·bar) without losing their salt rejection ability. The nanofiltration performances of these polyamide-based membranes are higher than most of the reported nanofiltration membranes in recent years.