Superhydrophilic-superhydrophobic micropattern on TiO2 nanotube films by photocatalytic lithography

The present paper describes an unconventional approach to fabricate the superhydrophilic-superhydrophobic micropatterns on the TiO2 nanotube structured film by photocatalytic lithography with a two-step process. At the first step, the superhydrophobic TiO2 nanotube film is fabricated through electrochemical and self-assembled techniques. And at the second step, the superhydrophobic film is selectively exposed to UV light through a photomask to locally photocatalyse the organic monolayer assembled on the TiO2 nanotube surface. The superhydrophilic-superhydrophobic micropatterns have thus been developed, as a novel template to fabricate a define micropatterned coating of nano octacalcium phosphate by electrochemical deposition. It is indicated that these combined processes reveal a very promising approach for constructing well-defined micropatterns of various functional materials. (C) 2008 Elsevier B.V. All rights reserved.