SiO_2@TiO_2/Acrylic Transparent UV Protective Layer for Cool Color Roofing Application

摘要

Transparent UV protective coatings were developed by incorporating nano-TiO_2 into waterborne acrylic systems to provide long-term UV protection for UV sensitive cool color roofing. Water based high crystalline TiO_2 nanoparticle suspension was prepared via a gel-sol method at a basic pH. The TiO_2 nanoparticles have an average size of 20 nm and are stable against agglomeration. As prepared TiO_2 nanosuspension is ready to be well dispersed in commercial waterborne acrylic resin system without extra surface modification. The fabricated TiO_2/acrylic nanocomposite coating achieved an UV cut-off below 350 nm with a visible transmission greater than 85% at 700 nm. It is also demonstrated that surface modification of Nano-TiO_2 with a SiO_2 insulation layer would suppress the catalytic activity of Nano-TiO_2 and improve the UV protection for UV and photocatalysis sensitive dyes.