Relation between crystallinity and chemical nature of surface on wettability: A study on pulsed laser deposited TiO{sub 2} thin films

Journal Article · Wed Jun 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3594695· OSTI ID:21538436

Shirolkar, Mandar M ^[1]; Phase, Deodatta; Sathe, Vasant; Choudhary, Ram Janay ^[2]; Rodriguez-Carvajal, J ^[3]; Kulkarni, Sulabha K ^[4]

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1. DST Unit on Nanoscience, Indian Institute of Science Education and Research, Pune, 411021 (India)
2. UGC-DAE Consortium for Scientific Research Indore Centre, Indore, 452017 (India)
3. Laboratoire Leon Brillouin (CEA-CNRS), CEA/Saclay, 91191 Gif-sur-Yvette Cedex (France)
4. DST Unit on Nanoscience, Indian Institute of Science Education and Research, Pune, 411021 India (India)

Pure titania (TiO{sub 2}) polycrystalline thin films in rutile, anatase and mixed phase have been grown on amorphous glass substrates by pulsed laser deposition method at various oxygen gas pressure. Wettability investigations have been carried out on these films. Consistent with our previous report [J. Phys. D: Appl. Phys. 41, 155308 (2008)] it has been observed that for nearly same surface roughness large contact angle or superhydrophobicity is present when sample has a pure single phase and lower contact angle or hydrophobicity when mixed phases were present. Structural characterizations suggest that in addition to roughness, pure phase film surface associated with hydrophobic sites and mixed phase film surface show association of both hydrophobic and hydrophilic sites, which might be inducing specific wetting character. UV treatment induces superhydrophilicity in the films. It was observed that UV irradiation causes nonequilibrium state on the TiO{sub 2} surface, leading to changes in the electron density, which in turn produces decrement in the crystallinity and lattice expansion. Reversible changes in the wetting state on the pure phase surfaces were observed to be faster than those on the mixed phase surfaces. We tried to establish the possible relation between crystalline phases, chemical nature of surface on reversible wettability besides the main governing parameter viz. surface roughness.

• OSTI ID: 21538436
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 12; Other Information: DOI: 10.1063/1.3594695; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRON DENSITY
ENERGY BEAM DEPOSITION
FALLOUT
GLASS
INVENTORIES
LASER RADIATION
LEVELS
OXYGEN
POLYCRYSTALS
PULSED IRRADIATION
REMOTE SENSING
ROUGHNESS
SEMICONDUCTOR MATERIALS
SIMULATION
SUBSTRATES
THIN FILMS
TITANIUM OXIDES
TRANSPORT THEORY
ULTRAVIOLET RADIATION
CHALCOGENIDES
CRYSTALS
DEPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
FILMS
IRRADIATION
MATERIALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SURFACE COATING
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS