Fabrication of super-hydrophobic surface on aluminium substrate and a study of surface frosting behaviours

Abstract

Frosting is common found natural phenomenon in late autumn or early spring, which sometimes brings unwanted effects or even disaster to human. With the development of science and technology, frosting may to some extend be mitigated by hydrophobic surfaces. Micro-Nanostructure was gained via chemical etching on aluminium surface. The surface was further modified by low surface energy polymer coating to form a very thin nano-layer on the surface. A kind of fluoroalkylsilane is used as the coating polymer. After fluorination treating, the aluminium surface become super hydrophobic with water contact angles more than150°. The surface was observed to be configured with plateaus and caves of micro-Nanoscale. In subcooled environments, frosting experiment was carried out on the surface of aluminium rods and aluminium sheets using humidifier to supply the water droplets. The comparison of the quantity of frost formed on the super-hydrophobic and untreated aluminium surfaces was conducted in the present work. And the quantity of frost formed on aluminium surfaces of different contact angles was compared. The results show that super-hydrophobic aluminium surfaces have obvious advantages in inhibiting frost. Besides, the contact angle has evident influences on restraining frost. Therefore, super-hydrophobic surfaces may serve as an effective means in decreasing the accumulation of frost on outside solid surfaces.