Development of coating formulation with silica-titania core-shell nanoparticles against pathogenic fungus

In the present study, we developed an antifungal coating formulation using silica, titania and silica-titania core-shell nanoparticles individually. The idea behind the synthesis of core-shell nanoparticles was to use the mechanical strength of silica and the antimicrobial property of TiO2 together. These nanoparticles were characterized by dynamic light scattering, transmission electron microscopy, scanning electron microscopy, EDX, FTIR and X-ray diffraction. Silica nanoparticles of 92 nm were prepared by the sol-gel process, while TiO2 nanoparticles and nano-core-shells were prepared through the peptization process with a size of 77 and 144 nm separately. The antifungal effect of the prepared nanoparticles was observed in potato dextrose agar media using the concentration of nanoparticles at 1 wt%. These nanoparticles were incorporated in two types of binder, polyurethane and polyacrylic, with the same concentration of nanoparticles. Coatings were applied on tiles, dried and tested against pathogenic fungus, and fungus growth reduction was observed up to 7-10 days. Coatings developed with TiO2 nanoparticles have shown good growth reduction of pathogenic fungus, but coatings formulated with silica-titania core-shell nanoparticles killed the fungus fusarium completely and have shown around 90% growth reduction for acremonium species also.