Preparation and characterization of hydrophobic alumina planar membranes for water desalination

A planar alumina membrane was prepared by a one-step phase-inversion tape casting method. The membrane consisted of a thick support layerwith finger-like large pores and a thin separation layer containing small pores with an average diameter of ∼0.76 m. The overall porosity of themembrane was ∼59%, as determined with the Archimedes method, and the porosity associated with the large, finger-like pores in the support layerwas ∼34% as derived from image analysis. The surface of this alumina membrane was converted from hydrophilic to hydrophobic via graftingwith a fluoroalkylsilane. The water desalination performance was tested by exposing the hydrophobic separation layer to an aqueous solution of2 wt.% NaCl at 80◦C, while a sweep of distilled water at 20◦C was used, resulting in a water flux of 19.1 L m−2h−1and a salt rejection over 99.5%.Due to the excellent water desalination performance, the hydrophobic porous ceramic membrane holds promise for practical applications.© 2014 Elsevier Ltd. All rights reserved