Abstract
Hydroxyapatite (HAP), Ca5(PO4)3(OH), given its similarity to human bone, shows great promise as a material with which to coat titanium orthopedic implants. In addition, silver nanoparticles can be deposited onto the HAP giving the coated implant antibacterial qualities to fight infection (metal nanoparticles upon a HAP structure also have potential as a catalyst support). This project characterized and compared an electrochemically deposited HAP coating bare, the HAP coating with electrochemically reduced Ag nanoparticles, and the HAP coating with sputter coated Ag nanoparticles. The techniques used for characterization included secondary electron imaging (SEI), backscattered electron imaging (BSD), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and image analysis/colorization software. It was found that the 1 um thick HAP coating readily accepted nanoparticles from both methods, with the electrochemically reduced Ag particles being significantly larger and more pervasive than the sputtered particles. EDS confirmed the presence of Ag in both, but in higher relative abundances using the electrochemical technique. AFM found the roughness of these nanoparticles to be 25-30 nm. The nanostructures from this deposition technique were found to be simpler to image, quantify, and characterize, than the sputtering technique, but both are viable options for producing Ag nanoparticle covered HAP coatings. Future work should focus upon studying the electrochemical processes themselves to ensure fewer abnormalities and defects.