Surface Wettability Modification By Micro-Arc Discharge

As an important feature of a solid surface,the wettability has important applications in medical,anti-fog,water separator,self-cleaning,anti-corrosion,fluid drag reduction and other fields.Therefore,the modification of wettability of the surface in recent years has become hot in materials science field.This article is about the subject of the wettability.Elaborated the impact of material wettability factors and the analysis of its principle.Thereby increasing the value of wettability in practice.The paper obtained the following conclusions:1.The ceramic oxide film of TiO₂ formed by micro-arc discharge at the electrode surface is hydrophilic and super-hydrophilic,and the contact angle of the surface between 0 °-50 °.Doping metal element in the electrolyte can increase the contact angle.Doping Ag element can make the CA of the surface material reaches close to 90 °and the surface material become quasi-hydrophobic.The most important factor affecting the wettability during the reaction is the length of the discharge that determines the structure,the thickness and crystal morphology of the ceramic oxide film.2.The ceramic oxide film of TiO₂ formed by micro-arc discharge is porous,and has similar crater fine pores.surface film of the electrode by pulse discharge is Uniform,the film by DC discharge electrodes and the surface of the burning phenomenon is more serious.Microporous pore size formed by pulsed discharge is between 2 t05μm,and by DC discharge between 1 to 3μm.When the pore size in the region of 1.2μm～1.6pμm,contact angle is maximum.Adding Ag and W in the electrolyte will make the surface of the film loading simple substance Ag and W which it will reduce the surface free energy,so that the contact angle of the surface becomes large.3.TiO₂ oxide film contained anatase and rutile,and anatase proportion greater than the proportion of rutile.4.Wettability can influence the photo catalysis of TiO₂.The photo catalysis will be better if the material is more hydrophilic.The addition of Ag can improve the antibacterial activity of TiO₂.