High performance reverse osmosis membrane with carbon nanotube support layer

Vertically aligned carbon nanotube (VACNT) wall membrane with its ultrafast water permeability shows a great promise as a novel support layer for membranes because of its ultrahigh porosity and hydrophobicity. In this work, we utilize the wall membrane as a support layer in forming a reverse osmosis (RO) membrane. For the purpose, a polyamide (PA) selective layer is grown by interfacial polymerization directly onto the top surface of the VACNT support layer. This RO membrane delivers a flux of 128.6 liter m(-2)h(-1) (LMH) and 98.3% salt rejection at 15.5 bar, opening an avenue for a leap over the water permeability at the rejection level that has been pegged at 5 LMH bar(-1)over the past ten years. Formation of a thin PA layer by a modified preparation method and ultrahigh porosity of VACNT support membrane are the main factors for the high performance RO membrane.