Gradient and weather resistant hybrid super-hydrophobic coating based on fluorinated epoxy resin

ABSTRACT A weather resistant super‐hydrophobic coating that can offer good substrate adhesion and yet to be easily processed at large scale can be of practical use in emerging fields of self‐cleaning and anti‐icing paint, combing all these properties together remains challenging task. Here we describe a composite coating composed of a fluorinated epoxy resin emulsion with embedded in situ surface‐modified dual‐scale nano‐silica, which displayed durable super‐hydrophobicity and excellent adhesive strength. The as‐prepared coating possesses water contact angle of 158.6 ± 1°, sliding angle around 3.8 ± 0.2° which remain stable even under acidic/alkaline, heat/cool, and accelerated aging treatment. The results demonstrate that surface roughness had a micron‐ and nanometer scale distribution with increased particle loading beyond 40 wt %. Through quantitative comparison of surface Attenuated Total Reflection (ATR) with bulk FT‐IR transmission spectra, a gradient coating with surface enrichment of hydrophobic groups was determined. The air‐side fluorinated polysiloxane‐rich layer endows coating with weather‐resistance and ultra‐hydrophobicity while bottom epoxy resin layer enhances substrate adhesion. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40955.