Colquhoun H.M.,University of Reading |
Chappell D.,University of Reading |
Lewis A.L.,ICI Plc |
Lewis D.F.,ICI Plc |
And 2 more authors.
Journal of Materials Chemistry | Year: 2010
A new class of high molecular weight polyethersulfone ionomers is described in which the ionic content can be varied, at will, over a very wide and fully controllable range. A novel type of coating process enables these materials to be deposited from alcohol-type solvents as cohesive but very thin (50-250 nm) films on porous support membranes, giving high-flux membranes (3.3-5.0 L m -2 h-1 bar-1) with very good, though not outstanding, salt rejection (typically 92-96%). A secondary layer of formaldehyde-cross-linked polyvinyl alcohol can be deposited from aqueous solution on the surface of the ionomer membrane, and this layer increases salt rejection to greater than 99% without serious loss of water permeability. The final multilayer membrane shows excellent chlorine tolerance in reverse-osmosis operation. © 2010 The Royal Society of Chemistry.