Fabrication of low-cost superhydrophobic coating on low-carbon steel using liquid flame spray

A nano-engineered superhydrophobic coating was fabricated using a two-step and low-cost method employing a liquid oxy-acetylene flame spray mechanism on mild A۵۱۶ steel. Oxygen and acetylene were used as flammable gases. Nanostructured coating was obtained by flame spraying aluminum nitrate solved in ethanol on the substrate. To lower the surface energy Perfluorodecyltriethoxysilane (PFDTES) and silicone elastomer were used. Results revealed that the wettability of the surface strongly depends on the precursor concentration so that at ۳.۵% concentration of aluminum nitrate in ethanol, maximum contact angle (۱۵۷°) occurs. The distance between the substrate and nozzle is another key parameter to control and it directly affects the contact angle. Sandpaper abrasion test showed outstanding mechanical durability so that the coating maintained in hydrophobicity range under the load of ۱۰۰ grams of weight and moving ۱۰ cm on sandpaper number ۱۰۰۰ for ۸ cycles. The parameters affecting the process were thoroughly analyzed according to the applied liquid flame spray mechanism and the appropriate performance range of each was obtained that According to the experiments, the precursor flowrate and the distance between the substrate and nozzle should be repectively ۰.۹-۱.۹ ml/min and ۱۴-۲۲ cm

Keywords:

Liquid flame spray , Nanostructured coating , Mechanical stability , Aluminum nitrate , Oxy-acetylene flame spray