Mechanically robust polyvinylidene fluoride (PVDF) based superhydrophobic coatings for self-cleaning applications

Abstract

The demand for effective self-cleaning, water repellant coatings has been growing over the years. Achieving superhydrophobic coatings with good mechanical durability has always been a key challenge. In this work, superhydrophobic surface was created by introducing silica nanoparticles in a polyvinylidene fluoride matrix (PVDF). The combination of a fluorinated polymer matrix and inorganic particulate fillers (SiO2) and surface functionalizing agent aminopropyltriethoxysilane (APTES) produced coatings with improved mechanical properties and good adhesion with the substrate. The static contact angle (CA) of the composite coating with PVDF: SiO2 = 1: 1 by weight was found to be 154° with a sliding angle of <2°. The mechanical properties of the coating, particularly hardness and Young’s modulus, effect of accelerated erosion and coating adhesion have been studied in detail. The effect of UV weathering on the coated surfaces is also tested. A simple self-cleaning test based on spectrophotometry is applied to quantitatively measure the self-cleaning performance of the coatings. The described coating process is simple and can be effectively scaled up for large structure protection.