Hydrophobically functional coatings can be used to protect surfaces and therefore improve the performance and
lifetime of a broad range of applications such as optoelectronics and touchscreens. Organic–inorganic hybridmaterials
such as silica sol–gel coatings are particularly effective for this purpose, but the functional molecules in
these coatings are susceptible to abrasive wear and thus lose their performance over time in the harsh environments
typically encountered. To combat these problems, a silica nanoparticle-reinforced matrix was developed
to increase hardness and wear resistance of the overall coating.
This study involved the abrasive wear analysis of fluorinated composite silica particle reinforced sol–gel silica
coatings dip-coated on glass substrates. Varying amounts of silica nanoparticles from0.5 to 10wt.% of the precursor
weight were added to examine the structural dependence of abrasive wear mechanisms to elucidate
strengthening mechanisms that could lead to improvements of coating properties. Abrasion was conducted
using an in-house built reciprocating polishing wear apparatus. Characterization of the water contact angle of
the coating was conducted to determine the hydrophobic functionality afterwear cycles. Atomic forcemicroscopy,
lateral force microscopy, nanoindentation, nano-scratch, contact angle goniometry, and optical microscopy
were performed at intervals of abrasive wear testing to characterize these wear mechanisms and the functional
degradation of the coating. It was generally found that, among other possible factors, the increased indentation
hardness of coatings led to a decreased wear rate. Additionally, an optimal amount of added colloidal
silica of 1–2 wt.% of the precursors provided the best overall mechanical, tribological, and functional
performance.