Fabrication and characterization of functionalized nano-silica based transparent superhydrophobic surface

Current work is focused on the fabrication and characterization of super-hydrophobic transparent thin-film coating to enhance the long-term mechanical and chemical stability and durability of the surface. Silica nanoparticles (Si-NPs) were first synthesized by the Stober process and then were functionalized to create a superhydrophobic surface with trichloro (methyl) silane (TCMS) as the coupling agent. The modified Si-NPs were then associated with a mixture of poly(vinyl alcohol) (PVA) and methylethyleketone (MEK). The Si-NPs were used for the coating of selected substrate materials i.e., plastic and hemp fabric surfaces, using dip-coating and paintbrush methods. Topographical and morphological characteristics of the developed functionalized Si-NPs coatings on plastic and fabric surfaces were investigated through scanning electron microscopy (SEM) and atomic force microscopy (AFM). The morphological analysis showed that the thin-film coatings of Si-NPs were homogeneously applied. X-ray diffraction (XRD) revealed the existence of Si-NPs on the surface. The surface hydrophobicity was measured experimentally through water contact angle (WCA) and water sliding angle (WSA) analysis. The largest WCA on fabric and the plastic slab was measured as 176.79. +/- 3. and 171.91. +/- 4. while the measured WSA for these substrates were 5. +/- 1. and 3. +/- 0.5., respectively. The maximum optical transmittance was achieved 89 % for the plastic slab. The coatings associated with PVA showed the best results for superhydrophobicity and durability.