Aerosol-assisted low-pressure cold spraying of TiO2 suspension

Cold spraying of metal oxides in the liquid medium is still in its early developmental stages but holds significant promise for advancing coating technologies. The use of suspensions minimizes agglomerate formation, mitigating the sandblasting effect of incoming feedstock particles and enhancing homogenization at the sub-micron level. Aerolization of the liquid suspension improves evaporation of the liquid component of feedstock material. Skipping prolonged and costly powder drying process makes the production easier and faster while use of a synthesis byproduct as a liquid is resource efficient. This study focuses on the low-pressure cold spraying of aerosolized sol-gel suspensions, leveraging lower temperatures and liquid feedstock to preserve sensitive active chemical groups particularly useful in photocatalytic degradation processes. The sol-gel technique, used for feedstock material preparation, forms organic-inorganic hybrid material that enables plastic deformation, thereby improving deposition efficiency. The formation of aerosols ensures well-dispersed feedstock with a narrow particle size distribution and minimal large agglomerates. Testing methods for evaluating feedstock materials include particle size and stability analysis, while coating characterization employs X-ray diffraction, Raman spectroscopy, optical spectroscopy, and scanning electron microscopy. This research aligns with the trend toward non-continuous deposition processes and the large-scale production of metal oxide coatings.