In situ deposition of hydroxyapatite on graphene nanosheets

Abstract

Graphene nanosheets were effectively functionalized by in-situ deposition of hydroxyaptite through a facile chemical precipitation method. Prior to grafting of hydroxyapatite, chemically modified graphene nanosheets were obtained by the reduction of graphene oxide in presence of ethylenediamine. The resulting hydroxyapatite functionalized graphene nanosheets were characterized by attenuated total reflection IR spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy and thermogravimetric analysis. These characterization techniques revealed the successful grafting of hydroxyapatite over well exfoliated graphene nanosheets without destroying their structure.

Graphene-based antibacterial composite coatings electrodeposited on titanium for biomedical applications

“…The peak for Ag3d peak (BE = 369.5 eV) agrees well with the literature data [42]. Observation of main peak O1s at binding energy of 531.3 eV for Ag/HAP/Gr coating is attributed to the presence of PO 4 3− groups incorporated within apatite lattice [43]. Survey spectra of the Ag/HAP/Gr coating revealed indisputable evidence of graphene incorporation, while no trace of C1s was detected for the Ag/HAP sample.…”

“…2b the most prominent bands at the wave numbers 1089, 1024, 962, 601, 560 and 470 cm −1 are attributed to stretching and bending of phosphate groups in hydroxyapatite. The low intensity band at 875 cm −1 is assigned to acidic phosphate group, HPO 4 2− ions [32]. The band at 630 cm −1 corresponds to structural OH − groups of HAP lattice [33].…”

“…Coherent domain sizes and microstrain of Ag/HAP/Gr coating were calculated by using (002), (211), (112), (300), (202) and (301) crystal planes. Difference between crystallite size before and after immersion is due to the CO 3 2-incorporation into the HAP lattice by occupying either the OH − or the PO 4 3− sites [49].…”

Electrochemical synthesis of nanosized hydroxyapatite/graphene composite powder

“…It is preferential substitution in the human bone known for its excellent bioactivity and osteoinductivity [41]. A vibration band located at 1640 cm −1 corresponds to the skeletal vibration of Gr due to aromatic sp 2 hybridized C=C vibration stretching [38,39,42], confirming its presence in the synthesized composite.…”

“…5 indicating the characteristic absorption bands of natural hydroxyapatite at 463, 569 and 603 cm −1 , which are attributed to the P−O bending of phosphate groups [37]. The three absorption bands of the PO 4 3− group were clearly distinguished in the composite HAP/ Gr nanopowder at 1092, 1038 and 960 cm −1 , which corresponds to the O−P−O phosphate ions of the hydroxyl site [38,39]. The characteristic band at 3572 cm −1 and weak broad band at 634 cm −1 can be attributed to the stretching and vibrational modes of the structural OH − groups of the hydroxyapatite lattice [40].…”