Inter layer-free P123 carbonised template silica membranes for desalination with reduced salt concentration polarisation tages

Carbonised template silica membranes were synthesised and investigated for water desalination for brackish (0.3 wt%), sea water (3.5 wt%) and brine (7.5 wt%) NaC1 solutions at temperatures range from 22 to 60 degrees C. The membranes were prepared by a two-step base catalysed sol-gel method using tetraethyl orthosilicate TEOS as the silica precursor and triblock copolymer of Pluronic P123 as the templating agent. The P123 silica membranes calcined under vacuum only produced high quality membranes by the interlayer-free method. The membranes were stable during testing of up to 250 h under different thermal and salt concentration solutions, always delivering very high salt rejections > 99.5%. It was found that by increasing the template concentration in the silica matrix from 5 to 50 wt%, salt concentration polarisation was greatly reduced. As such, high water fluxes were measured up to 8.5 kg m(-2) h(-1) for brackish water and 6.6 kg m(-2) h(-1) for brine water. (C) 2014 Elsevier B.V. All rights reserved.