Room temperature curable inorganic–organic hybrid nanocomposite hydrophobic coating: mechanistic understanding of the role of Ti(iv) and the diamine based curing agent

Abstract

Room temperature (RT; 30 ± 5 °C) curable inorganic–organic hybrid nanocomposite single layered transparent hard hydrophobic coatings have been developed on ceramic tile and glass substrates by sol–gel spray coating using (3-glycidyloxypropyl) trimethoxysilane (GLYMO), tetraethylorthosilicate (TEOS), polydimethyl siloxane (PDMS) trimethylsiloxy terminated, and poly (propylene glycol) bis (2-aminopropyl ether) as a curing agent in the presence of titanium(IV) isopropoxide (TTIP). The role of Ti(IV) and the diamine based curing agent in epoxy ring breakage toward enhancement of polymerization reaction and facilitating hard hydrophobic coatings has been investigated through a proposed mechanism. The bonding characteristics of the polymeric network were confirmed by ATR-FTIR. The coated substrates showed good pencil hardness (5H) with hydrophobic (water contact angle, WCA, 104 ± 2°) property. They exhibited good abrasion resistance, chemical durability, UV resistance and thermal shock resistance properties as evidenced from their WCA measurements. Nanoindentation measurements indicated an optimized effective hardness of 0.5162 ± 0.01 GPa and an elastic modulus of 6.73 ± 0.2 GPa at the load of 2 mN. The developed RT curable hard hydrophobic coating could find application in the fabrication of ceramic tiles for house-hold purposes as well as window glass for domestic uses and solar cover glass for efficient photovoltaic application.