Wetting behaviour of layers of TiO2 nanotubes with different diameters

Abstract
In the present work we investigate the wetting behaviour of nanotubular TiO2 layers (π-TiO2) grown by electrochemical anodization of Ti. As-prepared π-TiO2 layers show a super-hydrophilic behaviour while π-TiO2 layers covered by octadecylphosphonic acid (C18H37PO(OH)2) monolayer show super-hydrophobic behaviour. We demonstrated that the wetting properties significantly depend on the nanotube diameter.