Effect of Hydroxide Ion Concentration on the Morphology of the Hydroxyapatite Nanorods Synthesized Using Electrophoretic Deposition

摘要

The effect of OH- concentration on the morphology of the hydroxyapatite (HA) nanorod synthesized using electrophoretic deposition (EPD) method has been investigated. The growth of HA nanorods was achieved on polished titanium substrates. The electrolyte used in this study was prepared by dissolving calcium acetate (Ca (CH3COO)2H)2O), and Ammonium dihydrogen phosphate (NH4H2PO4) in distilled water without any surfactant, and was maintained at 80-130°C. Two electrolytes with OH- concentration of 10-4 and 10-10 were prepared. A highly homogeneous HA nanorods deposited on the titanium substrates were obtained after 1 h in the electrolytes with higher OH- concentration of 10-4. On the other hand, a flower-shaped HA nanostructures composed of needle-like HA crystals were obtained in the electrolyte of lower OH- concentration of 10-10. The deposits were identified as HA crystal rods grown along the c axis and perpendicular to the substrate. The HA deposits were characterized by scanning electron microscopy (SEM) while detailed structural characterization was done using a transmission electron microscope (TEM) equipped with selected area electron diffraction (SAED) patterns.