Exploiting the silicon content of aluminum alloys to create a superhydrophobic surface using the sol–gel process

Abstract A superhydrophobic surface was fabricated on aluminum–silicon alloy (Al/Si alloy) by using a sol–gel process to first create an evenly distributed superhydrophilic silica gel layer from the silicon contained within the alloy itself. The elevated surface energy of this silica gel layer was then used to achieve a superhydrophobic surface through the subsequent application of a monomolecular silane coating. Evaluation of this surface confirmed an average water contact angle of 166.04° and a sliding angle of 8.86°. The simplicity, low cost and low environmental impact of this fabrication method offers great potential for creating superhydrophobic Al/Si alloy surfaces on a commercial scale, thereby setting the foundations for a new field of industrial Al/Si alloy applications.