Coating of metallic surfaces with different surface roughness with zinc oxide nano-structures synthesized with a green approach and investigation of their properties

Ti6Al4V alloy is used as a metallic implant and prosthetic material in medical fields due to its strong corrosion resistance, excellent mechanical properties, bone-like modulus of elasticity, low density and allergenic potential. With interactions between body fluids and organs, corrosion, fatigue and wear can occur on the surface of implants. Surface modification processes in implant applications are effective methods to improve the biocompatibility and functionality of implants. The surface integrity of metal-based implants affects their quality, performance, reliability and lifetime. The mechanical properties, design, load transmission and biocompatibility of the implant material are affected by surface roughness. Coating the implant surface with metal and metal oxide-based nanoparticles (NPs) has been used to improve surface properties, corrosion resistance and biocompatibility. Among these NPs, zinc oxide (ZnO) stands out due to its excellent semiconductor, piezoelectric and photocatalytic properties. Coatingability and compatibility of NPs on metal-based surfaces are also affected by the roughness of the implant surface. In this thesis, green synthesis of ZnO inorganic doped hybrid NPs (Ginger/PEG-ZnO NP) in a polymer organic matrix consisting of vegetable and PEG prepared from ginger plant extract was carried out. The surface of Ti6Al4V alloy metallic parts prepared with different roughness values by machining method was dip coated with synthesized Ginger/PEG-ZnO NPs. UV-Vis, TEM, SEM-EDX, XRD, FTIR and DPPH methods were used to determine the structure and properties of Ginger/PEG-ZnO NPs and to measure the antioxidant capacity. SEM, surface roughness analysis, Stereo Microscope, microhardness measurements, contact angle measurements and MTT tests were performed to determine the properties of Ti6Al4V alloy parts with different surface roughness coated with Ginger/PEG-ZnO NPs. ZnO NPs exhibited homogeneous distribution in the ginger/PEG biopolymer blend matrix. ZnO NPs were mostly spherical nano-sized particles with an average particle size of less than 50 nm. According to the antioxidant activity measurements by DPPH technique, ZnO NPs were found to have acceptable antioxidant activity. Significant increases in the average surface roughness values were realized by increasing the feed rate in the lathe process used to obtain Ti6Al4V alloy surfaces with different surface roughness values. An increase in microhardness values was also observed with increasing surface roughness values. Significant increases in microhardness values were detected after coating. According to the contact angle measurement results after coating, the contact angles measured on the surface of all samples are less than 90°. With increasing surface roughness value of Ti6Al4V alloy before coating, surface contact angle decreased and diffusivity increased. According to the results obtained from MTT tests, cell viability above 70% was detected in all coated and uncoated Ti6Al4V alloys.