Photoinduced superhydrophilicity of amorphous TiOx-like thin films by a simple room temperature sol-gel deposition and atmospheric plasma jet treatment

Abstract

A room temperature sol gel process of TTIP / iPrOH / H2O /HNO3 sol was applied for the deposition of functional Ti alkoxide thin films on glass and polymeric substrates (PEEK). The unheated-amorphous films become superhydrophilic after 7 minutes of UV exposure which deteriorates after one day of storage in dark, exhibiting stable amphiphilic behavior. Superhydrophilicity is also obtained after 5 min of atmospheric pressure Ar-O2 plasma jet treatment. As the plasma power and the oxygen content of the mixture of the treatment increase (70W, 3.2 -5% O2) the films high hydrophilicity is maintained for many days even in dark atmospheric conditions providing long term hydrophilic coatings.