Effect of anions on the structural, morphological and dielectric properties of hydrothermally synthesized hydroxyapatite nanoparticles

Abstract

Synthetic nano hydroxyapatites (HA) have been considered as potential biomaterials for bone tissue engineering applications because of its excellent biological properties. The present work deals with the synthesis of HA nanoparticles from different anion source materials via autoclave assisted hydrothermal method. All the prepared HA nanoparticles were characterized by X-ray diffraction (XRD), Fourier transformation infrared spectra, field emission scanning electron microscopy, energy dispersive spectra and high resolution transmission electron microscopy. The XRD patterns reveal the pure and hexagonal phase structure with smaller crystallite size for HA obtained from various calcium salt precursors. HA particles prepared from nitrate precursors show spherical morphology with 32 nm grain size whereas those derived from the acetate, chloride and egg shell precursors respectively show needle-like, irregular and oval morphology. The effect of different anions on the dielectric properties and alternating conductivity of HA is investigated, as a polarized surface can trigger biological reactions. For the particles obtained from nitrate, acetate, chloride and egg shell precursors respectively give dielectric constant (εʹ) values of 9.96, 13.22, 9.92 and 10.86 at 5 MHz. The εʹ and dielectric loss (εʹʹ) values for the HA nanoparticles decrease with increase in the applied frequency as well. The alternating current conductivity values confirm that the as-synthesized HA samples exhibit insulating behavior. In short this article provides the various applicability of HA particles in optoelectronics and drug delivery.

Effect of nano-hydroxyapatite on protein adsorption and cell adhesion of poly(lactic acid)/nano-hydroxyapatite composite microspheres

“…The FTIR spectrum ( Fig. S1 (b)) further displayed the characteristic vibrations assigned to HAP (3563 cm −1 : OH-group in HAP; 1104 cm −1 , 1035 cm −1 , 963 cm −1 , 603 cm −1 , 565 cm −1 and 472 cm −1 : PO 4 3− group in HAP) [14,15]. TEM observation (Fig.…”

Impact of Mg2+ and Zn2+ Addition on the Structural, Morphological, Physicochemical, Dielectric and Biological Properties of Hydroxyapatite

“…Figure 1 illustrates the XRD patterns of the pure, 5% Zn, and 5% Mg-doped HA P . From the XRD pattern, the calculated lattice constants (a and c), unit cell volume (V) are in Table 2 and the crystallite size (D), microstrain (ε), dislocation density (ρ), the fraction of crystallinity (Xc) and speci c surface area (S) are in Table 3 [13,14]. All the XRD results are in good accord with the joint committee for powder diffraction standard (JCPDS) card # 09-432.…”

Impact of Dopants on the Electrical and Optical Properties of Hydroxyapatite

“…The dielectric properties of the chromium-doped HAp were also studied [8]. Various anions such as nitrate, acetate, chloride, and egg shell precursors have been used to prepare HAp particles and their corresponding dielectric constant were 9.96, 13.22, 9.92, and 10.86 at 5 MHz [9]. Porous HAp was prepared from Pila globosa shells which possessed high dielectric constant with low dielectric loss [10].…”