Preparation of Titania/Silica Core-Shell Hybrid Nanocomposites for 2024 Al-Alloy Corrosion Protection and Investigation of their Mechanical and Thermal Stability

摘要

Environmental friendly hybrid nanocomposite coatings have been synthesized using titania/silica core-shell nanoparticles for corrosion protection of 2024 aluminum alloy. In addition, their thermal and mechanical stability were investigated. The nanocomposite hybrid sols were prepared by hydrolysis and condensation of 3- glycidoxypropyltrimethoxysilane (GPTMS) and tetraethylorthosilicate (TEOS) in the presence of an acidic catalyst and bisphenol-A (BPA) as a cross-linking agent. The sols were then mixed with anatase nanoparticles and 1- methylimidazole as cross-linking initiator and cured at 130 °C after pre-drying at room temperature. The shape and size of the nanoparticles in the hybrid coatings were observed and determined using transmission electron microscopy (TEM). The thermal stability and optical quality of the samples were evaluated by TGA and UV-Vis spectrophotometry techniques. The storage modulus, glass transition temperature (Tg), and damping were also determined by DMTA tests. The results indicated that the modulus, Tg, damping, and thermal stability of the coatings depend on the TiO~(2)/SiO~(2)molar ratio.