Nanocrystalline Calcium Carbonate Hydroxyapatites Containing Multiwall Carbon Nanotubes: Synthesis and Physicochemical Characterization

• Published in: Russian journal of inorganic chemistry Vol. 63; no. 8; pp. 1001 - 1006
• Main Authors: Ezhova, Zh. A., Zakharov, N. A., Koval’, E. M., Kuznetsov, N. T.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2018; Springer Nature B.V
• Subjects: Ammonia; Apatite; Biomedical materials; Bones; Calcium carbonate; Calcium chloride; Carbonation; Carbonization; Chemical analysis; Chemical synthesis; Chemistry; Chemistry and Materials Science; Crystal structure; Hydroxyapatite; Infrared spectroscopy; Inorganic Chemistry; Morphology; Multi wall carbon nanotubes; Nanocomposites; Nanotubes; Organic chemistry; Surgical implants; Synthesis and Properties of Inorganic Compounds; Thermal analysis; X ray powder diffraction
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023618080065

Nanocomposites (NCs) based on carbonated calcium hydroxyapatite (CHA) (bioapatite, an analogue of the inorganic component of mammalian bone tissue), carbonate apatite (Ca 10 (PO 4 ) 6 CO 3 , CA), and multiwall carbon nanotubes (CNTs) are prepared in the system CaCl 2 –(NH 4 ) 2 HPO 4 –NH 4 HCO 3 –NH 3 –CNT–H 2 O (25°C) by coprecipitation of calcium and phosphorus salts with CNTs from aqueous solutions. The physicochemical properties of nanocomposites are studied as dependent on their formation conditions and composition using the solubility (residual concentrations) method and pH measurements. The composition, crystal structure, morphology, spectroscopic and thermal characteristics of the synthesized CHA/CNT and CA/CNT NCs are determined using chemical analysis, X-ray powder diffraction, thermal analysis, and IR spectroscopy. Either CHA/CNT NCs of composition Ca 10 (PO 4 ) 6 (CO 3 ) x (OH) 2–2 х · y CNT · z H 2 O, where х = 0.2; 0.5; 0.8; y = 1, 2, 3; z = 6.8–10.8, or (when х = 1) CA/CNT NCs of composition Ca 10 (PO 4 ) 6 CO 3 · y CNT · z H 2 O, where y = 1–3; z = 6.9–10.8, are formed as the carbonate and CNT contents of the NC increase. Our results favor the understanding of the effect of carbonization and CNTs on the metabolic formation of native bone tissue apatite and can be used for the design of efficient ceramics for bone implants.