Fabrication And Biological Properties Of Ag-doped Micropattern TiO₂Film

For human implants, it’s necessary to meet the requirement of hemocompatibility and cytocompatibility due to the complex mutual interaction with human tissue around. Whereas, surface modification is an important approach to improve the biocompatibility of implant materials. Therefore, this thesis selected TiO2for its preferable biocompatibility and studied influence of surface properties on the biocompatibility of TiO2by changing its composition and morphology.This thesis is mainly divided into two parts, the first part explored the effect of silver on the properties of silver-doped-TiO2thin film. Ag/TiO2thin films were prepared by sol-gel route, using butyl titanate and silver nitrate,at0,1/50,1/20,1/10,1/5(Ag/Ti) nominal atomic ratio. The films were analysed by Surface Profiler, scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results showed that the thickness of the films was approximately50-80nm and the size and the number of Ag particles increased as Ag/Ti nominal atomic ratio rose. XRD results indicated that the thin films were mainly anatase crystal and Ag dopant promoted the phase transformation, which inhibited the growth of anatase crystallite. According to XPS analysis, it can be concluded that actual Ag/Ti nominal atomic ratio was different from theory, and Ag species mainly existed as metallic. The amount of Ag2O species on the surface increased remarkably as the Ag/Ti nominal atomic ratio. The influence of Ag dopant on film performance was explored by photocatalysis, hemocompatibility, cytocompatibility, antimicrobial properties and other performance testing. It was found that the film with1/20Ag/Ti nominal atomic ratio exhibited the best photocatalytic performance, and the film with1/10Ag/Ti nominal atomic ratio displayed the best hemocompatibility. The results of endothelial cells culture showed that the silver has certain poisonous to the cells in the early culture stage, however, Ag dopant promoted endothelial cells adhesion after culturing1day and3day.The second part mainly explored the influence of the graphical on Tio2thin films and Ag/TiO2films. The graphical film was preparation and selected by using polystyrene colloidal mask and sol-gel. Then the films were analysed by SEM and XPS, indicating the faveolate morphology of the graphical film. Silicon substrate was exposed on the graphical film. The influence of graphical film on thin films properties was explored by hydrophily, photocatalysis, anticoagulant and cells culturing. The hydrophily results indicated that the graphical film after UV irradiating exhibited super hydrophily, whereas the film without UV irradiation was hydrophobic The photocatalysis results showed that the photocatalysis properties of the graphical film enhanced. The heomocompatibility evaluation displayed that the anticoagulant activity of the graphical film deviated without UV irradiation, whereas the anticoagulant activity of the graphical film (without Ag) improved. However, endothelial cells in vitro cultural demonstrated that the graphical film probably inhibited endothelial cells adhesion and spread.