Study On Surface Modification And Antibacterial Properties Of Medical Titanium Alloy

Titanium alloys have been widely used in the medical field due to their excellent properties,such as high specific strength,excellent corrosion resistance and good biocompatibility.It has been widely used in the medical field,especially as an implant material has broad development prospects.However,a bacterial infection may occur when the implant materials are implanted in the body which causes tremendous pain to the patient.Therefore,how to solve the bacterial infection problem has become one of the urgent problems in medicine.In this paper,the iodine solution was used as the electrolyte to modify the surface of the titanium alloy by electrodeposition to prepare the antibacterial coating,and the biological properties such as antibacterial and sustained release were studied.The main conclusions are as follows:(1)An antibacterial coating was prepared on the surface of the titanium alloy by electrodeposition using povidone iodine(PVP-I)and potassium iodide(KI)as electrolytes,respectively.When the electrolyte was povidone iodine,about 9.19wt%iodine content in the antimicrobial coating was prepared.Three forms of iodines in the antibacterial coating were tested by XPS analysis,which was I₃^-,I₂H-O₂ and I₂O₅,respectively.The antibacterial performance test results show that the iodine-containing coating has a good antibacterial effect.The comprehensive antibacterial rate of the coating against Staphylococcus aureus was 63.3%and the antibacterial rate of E.coli was 48.5%.The temperature stability results showed that the antibacterial coating maintained good temperature stability at 250°C.After 21days in the simulated body fluid,the iodine content remained 60.36%.It shows a certain sustained release property.When the electrolyte is KI,the iodine content in the antibacterial coating is about 10.54 wt%.Two forms of iodines were tested which was I₂ and I₂O₅,respectively.Antibacterial test results show that the iodine-containing coating exhibits excellent antibacterial effects.The antibacterial rate of the coating against Staphylococcus aureus was 99.7%,and the antibacterial rate of E.coli was91.7%.the iodine content remained 67.3%after 21 days in the simulated body fluid.It shows a certain sustained release property.The antimicrobial coating maintains good temperature stability at 200°C.(2)The surface of the titanium alloy is pretreated by anodization and Ti O₂nanotube arrays were prepared on the surface of the titanium alloy.Then,the antibacterial coating was prepared by electrophoretic deposition of iodine on Ti O₂nanotubes with povidone iodine(PVP-I)as electrolyte.The SEM results showed that the Ti O₂ nanotube tube has a length of 4.2?m and a tube diameter of 230 nm.The EDS test results show that the iodine content in the antibacterial coating is about2.12wt%.There are three forms of iodines in the antibacterial coating by XPS analysis which was I₃^-,I₂H-O₂ and I₂O₅,respectively.The antibacterial performance test results show that the iodine-containing coating has a good antibacterial effect,the comprehensive antibacterial rate against Staphylococcus aureus was 56.36%and the antibacterial rate of E.coli was 79.46%.With povidone iodine as the electrolyte,the iodine content remained 85.33%after 21 days in the simulated body fluid.Compared with the direct deposition of iodine on the surface of titanium alloy,the antibacterial coating exhibits excellent sustained release properties due to the presence of Ti O₂nanotubes after pretreatment with anodizing.