Photo-induced hydrophilicity

Photoinduced Surface Reactions on Ti02 and SrTi03 Films Photocatalytic Oxidation and Photo-induced Hydrophilicity. 283... 

Photo-oxidative self-cleaning and antifogging effects of transparent titanium dioxide films has attracted considerable attention for the past decade [334, 335]. In order to understand the photo-induced hydrophilic conversion on titanium dioxide coatings in details, it is inevitably necessary to understand the relationship between the photo reaction and the surface crystal structure this can be done, for example, by an evaluation of the photo-induced hydrophilic conversion on the different crystal faces of rutile single crystals and also... 

Zhang L, Diflert R, Bahnemann D, Votmoor M. Photo-induced hydrophilicity and self-cleaning models and reality. Energy Environ Sci 2012 5 7491-507. 

In situ degradation of the azo dye methyl orange in aqueous solution was performed in the presence of various pure and Ag metal ion-doped titania thin films, prepared with and without surfactants. The main aim of the study was to analyze the effect of non ionic surfactant (Pluronic F-127), Ag metal ion doping and their combined effect on the photo-induced hydrophilicity and photocatalytic degradation of ambient air contaminants (gas-solid interface), methyl stearate (solid-solid interface) and azo dye methyl orange (liquid-solid interface). 

Figure 17-5. The mechanism of photo-induced hydrophilic conversion.

The application for thin film coating has been accelerated by this discovery of photo-induced hydrophilic conversion on photocatalytic surface. Requirements for such novel application of photocatalytic coatings have accelerated R D ofphotocatalytic coatings for the last decade. The major progresses were development of preparation technologies for each application and also development of novel materials not only for photocatalyst but also for binder or intermediate layer for photocatalytic coatings. 

Yu, J.G., J.C. Yu, W.K. Ho and Z.T. Jiang (2002c). Effects of calcination temperature on the photo-catalytic activity and photo-induced super-hydrophilicity of mesoporous Ti02 thin films. New Journal of Chemistry, 26(5), 607-613. 

Photocatalytic Active Surfaces and Photo-Induced High Hydrophilicity/High Hydrophobicity... 

Fig. 6 Comparison of self-cleaning effects (left) conventional photocatalytic oxidation process, (right) washing away by rainwater due to photo-induced highly hydrophilic surface...

The pendant functions listed in Figure 3 are often useful and of synthetic interest per se. For example, methacrylate and acrylate esters are polymerizable (cross-linking sites) [19-21] the cinnamate is photorespon-sive (for the photo-induced dimerization of its unsaturated groups) [20] oligo(oxyethylene) [25-27] and carbohydrate groups [35] give hydrophilic and water-soluble polymers, whereas perfluoroalkyl moieties [32-34] enhance hydrophobicity. Thus, poly(vinyl ethers) with cinnamate functions... 

M. Ulbricht, H. Matuschewski, A. Oechel, H.-G. Hicke, Photo-induced graft polymerization surface modifications for the preparation of hydrophilic and low-protein-adsorbing ultrafiltration membranes. Journal of Membrane Sdence 115 (1996) 31. 

In the present paper we review some of our findings on the reversible photo-induced wettability changes of polymer surfaces doped with photochromic spiropyran molecules. We illustrate how the hydrophilicity of the surfaces is enhanced upon UV laser irradiation when the embedded non-polar spiropyran molecules convert to their polar merocyanine isomers and how this process is reversed upon irradiation with green laser pulses. Moreover, we show that, when the doped polymer surfaces are micropattemed by soft molding lithography or by interferometric... 

Photo-Induced Super-Hydrophilicity on Filmed Ti02 Surface... 

Oreophobic/hydrophilic surface is a final photo-induced surface caused by the surface structural change. It is considered that each crystal grains exhibit amphiphilicity or other... 

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