Optimization of industrial aerosol nanoparticle generation process for creating photocatalytic and anti-microbial surfaces

摘要

Flame methods are a promising way to manufacture nanoparticles in commercial scale. They are widely utilized already. In this study, a process called Liquid Flame Spray, LFS, is used. It is commercially known as nHALO (Hot Aerosol Layering Operation, Beneq Oy). In LFS, liquid precursor is fed into a turbulent hydrogen-oxygen flame. LFS can be used in production of nanoparticles which are deposited on a substrate. Even multicomponent nanoparticles can be manufactured using LFS process. LFS is a versatile method for nanoparticle generation. In this study, we use LFS to produce an anti-microbial titania-silver nanoparticle coating on ceramic tiles and float glass. The coating is produced by collecting TiO2-Ag nanoparticles directly from the flame. The particles are deposited on the surface. Some of the excess particles are not properly attached. The coating is then characterized using electron microscopy, contact angle measurements, organic and biofilm removal tests and bacterial tests. Scanning Electron Microscopy (SEM) images indicate that the titania-silver coating covers the tiles even after scrubbing away the loosely adhered particles. Tunnelling Electron Microscopy can be used to obtain information about the particle morphology. TEM micrographs suggest that the coating is formed of 10 to 20 nm TiO2 particles and small Ag nanoparticles on the surface of TiO2. The size of the Ag particles is few nanometres.