Study of the effect of silica nanoparticles on the conservative properties of acrylic coatings

In this work the properties of acrylic coatings based on Paraloid B72 were improved by adding of silica nanoparticles. Pre-formed silica nanoparticles، prepared by sol-gel chemistry from thetraethoxysilane (TEOS) and methacryloxypropyltrimethoxysilane (MPTMS) precursors، were dispersed into acrylic coatings using a homogenizer. Steel sheets were used as substrate. Morphology and the dispersion of nano-silica particles in the coatings were investigated by scanning electron microscopy (SEM)، and transmission electron microscopy (TEM). Topography and surface roughness of the coatings were also evaluated using atomic force microscopy (AFM). The effect of incorporation of silica nanoparticles on the conservative behavior of the coatings was investigated using contact angle measurements and UV aging tests. The modified coating with a proper amount of silica particles showed more efficient performance than the net coating which can be mainly inferenced from its more less color changes after 1000 hr UV radiation and also its more hydrophobic nature than the net coating. In general، the study shows an improvement in the conservative characteristics (from the wet ability and color change point of view) of the properly nano-particle modified coating، confirming the positive effect of nano silica addition in acrylic coatings.