| Abstract |
Hydrophobic surfaces are required for a variety of applications owing to their water repellent and selfcleaning properties. In this work, we present a novel approach to prepare durable hydrophobic surfaces on porous ceramics. A polydimethylsiloxane (PDMS) film was applied to a porous alumina wafer, followed by pyrolysis at 400 degrees C in a non-oxidizing atmosphere (H-2: N-2 = 5:95), giving rise to nanoparticles. In these particles, Si,C and O elements formed amorphous networks to which methyl groups that had survived the pyrolysis were bonded. The as-modified porous alumina wafer was hydrophobic with a water contact angle of 136, which is attributed to the presence of the methyl groups. The hydrophobicity was maintained after immersion in aqueous solutions in a pH range of 2-12 and acetone. The hydrophobicity was also retained after exposure to temperatures as high as 450 degrees C in an oxidative atmosphere (air) and after mechanical abrasion with sandpaper. The hydrophobic porous alumina ceramics developed in the present study are promising for use as membranes in various separation processes. (C) 2017 Elsevier Ltd. All rights reserved. |
