Coating of zinc substrates with fluorosilane molecules using a water-treatment technique as a pre-coating procedure for the creation of superhydrophobic surfaces

Superhydrophobic surfaces were successfully created when zinc substrates were coated with molecules with low surface energy through grafting of fluorosilane molecules. The zinc substrate underwent water-treatment technique as a pre-coating procedure to enhance the reaction sites for the grafting of fluorosilane molecules. The water contact angle of the samples went as high as 161.1° ± 0.8°. At lower fluorosilane-ethanol soaking times, water contact angles have lower values while at higher soaking time, it has higher water contact angle values. At 240 min fluorosilane-ethanol soaking time, optimum value of water contact angle was achieved. Fluorosilane molecules are widely distributed through the zinc substrate surface as inferred from the mapping of the silicon atoms through Energy Dispersive Spectroscopy. As inferred from the Infrared Spectroscopy, water treatment process enhances presence of Zn‒OH moieties which are perceived to be binding sites of fluorosilane molecules. The presence of vibrational modes related to Si‒O and C‒F were detected after the water-treated samples were soaked in fluorosilane-ethanol solution; the said vibrational modes were attributed to the presence of grafted fluorosilane molecules.