Self Assembly of Super-hydrophobic Nanotextured Methyl Functionalized Silica on Copper and Aluminium Surfaces for Moist Air Condensation

Abstract The super-hydrophobic surfaces enhance the transport coefficients of the condensation process and therefore it is very useful in water harvesting devices. In the present study, super-hydrophobic substrates are fabricated by growing self-assembled silica nanostructures on copper (Cu) and aluminum (Al) surfaces by a sol-gel based solution immersion method at room temperature. The contact angles measured were 155 ± 2° and 156 ± 2° on coated Cu and Al surfaces respectively. The water condensation rate on the coated Cu surface significantly increased from 188 ml/m2-hr to 630 ml/m2-hr, while that of the coated Al surface increased from 190 ml/m2-hr to 650 ml/m2-hr. The present work shows that the metallic substrates with super-hydrophobic coatings have excellent potential for water harvesting from moist air, and they were effectively used for more than 120 days.