A COMPARATIVE STUDY OF SOLID-TO-SOLID AND WET PRECIPITATION FOR THE FABRICATION OF GRAPHENE OXIDE-HYDROXYAPATITE NANOCOMPOSITE

Graphene oxide (GO)-reinforced hydroxyapatite (HA) plays significant role in formulations applied in medicine. In this work, HA was obtained by wet chemical precipitation and GO was synthesized via a Hummer's method. GO-HA nanocomposites were prepared via two techniques, namely, solid-to-solid precipitation (Ss) and wet precipitation (Wp) methods. The morpho-structural properties of composites prepared using the two techniques with different GO contents were compared. The obtained samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, and transmission electron microscopy (TEM). FTIR, XRD, and SEM analyses showed that the GO-HA consisted mainly of HA phase. Elemental composition of oxygen of GO-HA by Ss and Wp were 34.58% and 58.69%, respectively, which confirmed the introduction of GO to HA. The average particles sizes (in width) of HA and 2.0 wt% of GO-HA by Ss and Wp were 37.28 +/- 1.47 nm, 32.56 +/- 1.29 nm and 32.98 +/- 0.94 nm, respectively Raman spectroscopy illustrated that there was new peak of HA in GO-HA nanocomposite. TEM analysis verified that GO was incorporated into the nanocomposite. GO-HA nanocomposites were successfully obtained via the two methods, in which the GO-HA obtained by Wp method presented a densely packed and well-defined dispersed HA onto GO nanosurface, whereas that obtained by Ss method presented randomly positioned HA particles onto GO sheets. Wp technique can be considered as a simple and convenient GO-HA fabrication technique for biocompatible implant coatings.