Alkanoic and phosphonic acid derived self-assembled monolayers (SAMs) were formed on magnesium alloy by the vapor phase method. AFM and XPS studies showed that SAMs were formed on Mg alloy. The chemical and anticorrosive properties of the SAMs prepared on magnesium alloys were characterized using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. Water contact angle measurements revealed that, although SA and ISA have the same headgroup to anchor to the magnesium alloy surface, the packing density on the magnesium alloy surface could be considerably different. The contact angle hysteresis of SAMs with a carboxylate headgroup is much larger than that of SAMs with a phosphonic acid group. The XPS O 1s peaks indicated more likely a mix of mono-, bi-, or tridentate binding of phosphonic acid SAM to the oxide or hydroxide surface of the Mg alloy. The electrochemical measurements showed that the phosphonic acid derived SAM had better corrosion resistance compared to alkanoic acid derived SAM. The chemical stability of SAMs modified magnesium alloy was investigated using water contact angle and XPS measurements. The water contact angle and XPS measurements revealed that the molecular density of OP and PFEP on magnesium alloy would be higher than those of SA and ISA on magnesium alloy.

A hydroxyapatite is most suitable biomaterial for clinical application, because it is a main component which constitutes bones and teeth of an organism. Since the hydroxyapatite has different biocompatibility and absorptive activity of proteins for its crystal plane, it is necessary to use the appropriate crystal plane for use in vivo. Thus, the crystal orientation of the hydroxyapatite is one of the very crucial subjects in biomaterials processing. In this study, the control of crystal orientation of the hydroxyapatite has been conducted in the colloidal filtration (slip casting) process under a high magnetic field and a new process where the high magnetic field is introduced in the heat substrate method developed by Okido et al. The usefulness of the processes has been confirmed through the orientation index evaluated by X-ray diffraction patterns and scanning electron microscope (SEM) images of hydroxyapatite crystals. The crystal axis of hydroxyapatite aligned by a magnetic field was determined.

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