Preparation And Characterization Of Mesoporous/Macroporous TiO2Coatings On The Surface Of Titanium Alloy

Titanium and its alloys are widely used in oral medicine for its excellent mechanical property and biological safety, the research of the titanium-based implant materials is a hot topic. However, titanium and its alloys are bioinert and cells in the surface are difficult to grow. In addition, titanium and its alloys are not resistant to corrosion in the complex environment of oral electrolyte. Therefore, titanium and its alloys are necessary to be modified before being used as the implant materials.In this study, a simple sol-gel template method was firstly employed to prepare mesoporous TiO2coatings on the Ti-6A1-4V alloy. Then, a modified method was developed to prepare mesoporous/macroporous TiO2coatings on surface of Ti-6A1-4V alloy via evaporation induction self-assembly technology and gravity settlement technology. In this method, polystyrene (PS) spheres and P123are used as macroporous and mesoporous template reagents. Furthermore, cytocompatibility and corrosion resistance of Ti-6A1-4V alloys coated with mesoporous/macroporous TiO2coating, conventional TiO2coating, and pure alloy itself in the three kinds of physiological electrolytes were investigated. Based on above research, it is anticipated that the presented method can be applied to promote potential applications of the porous TiO2coatings in the field of surface modification of titanium and its alloys.The main results are drawn as follows:1. the mesoporous TiO2microstructure was prepared in the Ti-6A1-4V alloy surface, whose aperture, specific surface area and volume are6.6680nm,124.1906m2/g and0.256470cm3/g, respectively.2.(1) The modified sol-gel template method was used to prepare mesoporous/macroporous TiO2coatings on surface of Ti-6A1-4V alloy. There are various types of pore structure coexisted, namely, macroporous structure with the diameters of700nm-800nm,150nm-250nm, and mesoporous structure with the diameter of5-7nm, respectively.(2) In the three kinds of physiological electrolytes (simulation artificial saliva, simulation artificial body fluids and0.9%saline), electrochemical corrosion performance of the prepared samples was studied and compared by electrochemical method. Among these samples, the anti-corrosion performance of mesoporous/macroporous TiO2coatings is the best, while those of conventional TiO2coatings and Ti-6A1-4V alloy are very close. The corrosion resistances of samples in the three kinds of physiological electrolytes are:simulation artificial saliva>0.9%saline> simulation artificial body fluids.(3) Cytocompatibility of MC3T3-E1cells on the above samples was also investigaed. It is obtained that mesoporous/macroporous TiO2coatings can improve cytocompatibility of the Ti-6A1-4V alloy, i.e., growth and differentiation of MC3T3-E1osteoblast cells can be effectively promoted.