Facile preparation of self-healing superhydrophobic CeO2 surface by electrochemical processes

Abstract

Highlights ・The CeO-coating is formed on Type 304 stainless steel by anodic deposition. ・The hydrophilic CeO 2 surface is transformed to hydrophobic during air exposure. ・Superhydrophobic CeO 2 surface is obtained on hierarchically rough substrate. ・Superhydrophobic CeO 2 surface shows self-healing property.

Investigation of the Hydrophobic Nature of Metal Oxide Surfaces Created by Atomic Layer Deposition

“…Similar increased hydrocarbon adsorption on CeO 2 surfaces resulting in higher contact angles in comparison to that of other oxide films has been previously reported for ceria pellets. , These results suggest that carbon adsorption on CeO 2 surfaces is relatively spontaneous and favorable, which can be explained by the presence of oxygen vacancies in ceria and hence an increase in the number of adsorption sites . The findings reported in this work are in agreement with previously published studies, which note that CeO 2 is initially hydrophilic but quickly becomes hydrophobic upon atmospheric exposure and the resulting carbon adsorption on the surface. ,,,,, There have been a number of studies, which assigned an intrinsic hydrophobic nature to ceria and other lanthanide oxides. ,,,− However, we found that to measure the intrinsic wetting properties of a high-energy surface like ceria, it must undergo a proper cleaning procedure prior to the contact angle measurements. The hydrophobic nature of CeO 2 has typically been observed after the surface was rinsed with organic solvents or water, which we found is not effective for removing carbon contaminants.…”

Enhanced Hydrophobicity of CeO2 Thin Films by Surface Engineering

“…The first one is related to the time of saturation for wetting properties. In various works [6]- [9], [18], the period of establishment for the hydrophobic state of CeO2 and other REOs is found in the large range from days to months. Applying the deposition process in a saturated environment allows the completion time to be reduced from days to hours.…”

Fabrication of Superoleophobic Surface on Stainless Steel by Hierarchical Surface Roughening and Organic Coating

“…Organic surface is usually required to satisfy this criterion, although there are some reports indicating that rare earth oxides exhibit hydrophobicity without any organic coating. [17][18][19] In contrast to the superhydrophobic surfaces, the fabrication of superoleophobic surfaces is rather difficult because of the lower surface tension of oils. The most organic surfaces with -CH 3 , -CH 2 , -CF 2 and -CF 3 outermost groups are oleophilic with static contact angles less than 90° for the low surface tension liquids ( < 30 mN m − 1 ); these organic surfaces are wetted to oils even after surface roughening.…”