Abstract:

BACKGROUND: The prepared hydroxyapatite is likely agglomerated due to its specific surface area.
OBJECTIVE: To investigate the agglomeration problem of hydroxyapatite and to improve the dispersity of hydroxyapatite.
METHODS: The nano-hydroxyapatite was prepared using solution coprecipitation method from calcium nitrate and ammonium di-hydrogen phosphate and further modified by combination of polyethylene glycol (2%, 4%, 5%, 6%, 8%), polyvinyl alcohol (2%, 4%, 5%, 6%, 8%), and stearic acid (2%, 4%, 5%, 6%, 8%).
RESULTS AND CONCLUSION: Nano-hydroxyapatite was successfully obtained through X-ray diffraction analysis. The type of surface modifying agent and active agent concentration could affect the particle size of the hydroxyapatite when cladded by them. After considering the influential factors in processes of synthesis and modification, the following conclusions can be determined: Polyethylene glycol is the best modifying agent for hydroxyapatite in all three modifying agents which involve polyethylene glycol, polyvinyl alcohol and stearic acid. Furthermore, the dispersity of the hydroxyapatite is excellent after modification by 5% polyethylene glycol.

Key words: biomaterials, material mechanics and surface modification, nano-hydroxyapatite, nano-modification, dispersing agent, solution coprecipitation method, nano-agglomeration, surface modifying agent, polyethylene glycol, polyvinyl alcohol, stearic acid