Effect of Functionalized Carbon Nanotubes on the Synthesis of Hydroxyapatite Nanoparticles

The purpose of this study was to investigate the effect of the functionalized carbon nanotubes (CNT) on the nucleation of the HA nanoparticles. In this work, solutions of calcium nitrate tetra hydrate and diamonium hydrogen phosphate in water were used as Ca, P precursors. The former solution was added to an aqueous suspension of MWNTs-COOH. Different CNT functionalization percentage ratios of 1%, 2%, 3%, 4% and 5% were examined. X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) experiments confirmed that the resulting powders were composed of hydroxyapatite. The Scanning Electron Microscopy (SEM) images illustrated a short distance effect of CNTs on the formation of the HA nanoparticles. In addition, a more detailed observation performed by Transmission Electron Microscopy (TEM) depicted the flake-like morphology of the nanoparticles. Based on the results of this research, the crystallinity decreased due to the CNT addition to the synthesis media. The sample containing a CNT functionality percentage of 5% revealed a preferred crystalline orientation compared with the samples composed of less CNT functionality percentage of 1%, 2%, 3% and 4%.