Preparation and characterization of superhydrophobic hybrid coatings based on polyurethane/silica nanoparticles

Abstract

Superhydrophobic coatings based on polyurethane/silica nanoparticle hybrids were fabricated onto a cotton fabric by spraying a mixture of modified silica nanoparticles with poly(tetramethylene glycol)(PTMG) and polyisocyanate onto the fabric and a subsequent curing at 80℃. Surface modification of silica was carried out by polydopamine(PDA) coating followed by treating it with dodecyl amine or octadecyl amine. The coated fabrics were characterized using water-contact angle measurement and SEM analysis. The hydrophobicity of the cured PU/modified SiO2 coatings can be affected by the alkyl chain length of the modified silica. The coated fabrics exhibit superhydrophobicity with a water contact angle of over 160 ° along with excellent self-cleaning and water/oil separation ability. Further, the coated fabric exhibited deicing performance by photothermal effect. These effecs was also revealed that such superhydrophobicity was maintained after repeated mechanical abrasion using a sandpaper.