Combining a molecular modelling approach with direct current and high power impulse magnetron sputtering to develop new TiO₂ thin films for antifouling applications

Authors

J. Guillot, E. Lecoq, D. Duday, E. Puhakka, M. Riihimäki, R. Keiski, J. B. Chemin, and P. Choquet

Reference

Applied Surface Science, vol. 333, pp. 186-193, 2015

Description

The accumulation of crystallization deposits at the surface of heat exchangers results in the increase of the heat transfer resistance and a drastic loss of efficiency. Coating surfaces with a thin film can limit the scale-surface adhesion force and thus the fouling process. This study compares the efficiency of TiO₂ layers exhibiting various crystalline planes and microstructures to reduce the kinetic of fouling. Molecular modelling with density functional theory is first carried out to determine the energy of CaCO₃ deposition on anatase (1 0 1), (0 0 4), and (2 0 0) surfaces as well as on a rutile (1 0 1) one. TiO₂ thin films (thickness < 1 μm) are then synthesized by direct current and high power impulse magnetron sputtering (dcMS and HiPIMS respectively) in order to tune their crystallinity and microstructure. Lastly, the induction time to grow CaCO₃ crystals at the surface of such materials is determined. Comparing the modelling and fouling results allows to draw general trends on the potential anti-scaling properties of TiO₂ crystallized under various forms. Until now, such a comparison combining a theoretical approach with experimental fouling tests has never been reported in the literature.

Link

doi:10.1016/j.apsusc.2015.01.199