Comparative studies on polyacrylic based anti-algal coating formulation with SiO₂@TiO₂ Core-shell nanoparticles

In the present study, we developed anti-algal coating formulation with silica (SiO2), titania (TiO2) and silica-titania core-shell nanoparticles individually. This core-shell nanoparticle was formulated because of silica is a hard material that provides the mechanical strength and shell TiO2 on core silica can impart the antimicrobial property of material. These nanoparticles were prepared through sol-gel process and peptization process and characterized by dynamic light scattering, UV-visible spectrophotometer and X-ray diffraction. Particle size was measured 90 nm for silica nanoparticle prepared through sol-gel process. TiO2 nanoparticle size was measured 107 nm prepared through sol-gel synthesis and 77 nm prepared through peptization process. Particle size of silica-titania core-shell nanoparticle was measured 240 nm prepared through sol-gel process and 144 nm from peptization process. The coating formulation were developed with the above nanoparticles individually and nanoparticle concentration was maintained at 4 % (wt) in polyacrylic binder. These coatings were applied on bricks for anti-algal testing against green algae and mixed algae. Optical density was measured of these samples at 665 nm up to 120 h and observed that nano-coating developed with silica-titania core-shell nanoparticle prepared through peptization process has shown good anti-algal effect as compared to nano-coating developed with silica-titania core-shell nanoparticles prepared through sol-gel process.