The effect of reduction of graphene oxide on the formation of hydroxyapatite and tricalcium phosphate

This study reports on biomimetic mineralization route employing reduced graphene oxide (RGO) at different rates as a template material for biomineralization of biphasic hydroxyapatite/tricalcium phosphate (HAP/TCP). RGO-HAP/TCP hybride composites were synthesized via biomineralization in Simulated Body Fluid (SBF). GO was prepared from pristine graphite by Hummers and Offeman method. GO nanoparticles were reduced with sodium borohydride (NaBH4) before soaking in 5xSBF for 3 weeks at 37 degrees C and 7.4 pH to performing biomineralization. Surface area and average size distribution of fabricated GO were found as 813.2 m(2) g(-1) and 1.2968 mu m by using BET and DLS technique, respectively. All surfaces are overall negatively charged and zeta potentials of GO, R(1)GO, R(2)GO, R(3)GO were found to be -35.05, -30.01, 29.5, -29.01 and -28.9, respectively in the neutral pH. The contact angles of GO, R(1)GO, R(2)GO and R(3)GO are 33.5 degrees, 55.3 degrees, 57.4 degrees and 61.1 degrees, respectively. The ID/IG values determined by Raman are 1.07, 1.04, 1.02 and 1.01 for GO, R(1)GO, R(2)GO and R(3)GO, respectively. After the reduction, its maximum peak at 236 was clearly shifted to 260, 264 and 267 nm for R(1)GO, R(2)GO and R(3)GO. The precipitation of biphasic HAP/TCP on R(1)GO and R(2)GO was confirmed by XRD, FTIR and TGA analysis. (C) 2017 Elsevier Ltd. All rights reserved.