Pretreatment ultrasonic cleaning

Similar to transparent conducting glasses, a titanium substrate has to be cleaned before the growth of nano-structured Ti02 materials. A typical titanium pretreatment process can be found in published literatures (Liu et al., 201 la). In brief, it is first cleaned with acetone followed by absolute ethanol. Then it is washed with distilled water. Afterwards, it is boiled in 10 wt.% oxalic acid for 30 min to remove the potential oxide layer. Finally, it is ultrasonically cleaned in water for 15 min followed by air-drying in the atmosphere. 

Substrate surfaces are frequently contaminated with oils, greases, etc. and a common pretreatment is degreasing either with steam, or by wiping the surface with solvent-dipped clean cloths, or most effectively in liquid and vapour degreasing baths, possibly using an ultrasonic agitator. Commonly used solvents are 1,1,1-trichloroethane or perchloroethylene, and they should be checked periodically for the formation of corrosive acid. 

Pretreatment Code Ultrasonics Contact angles after x 0 2 ninutes in cleaning solution 5 10 20 ... 

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