Influence of temperature, ripening time and calcination on the morphology and crystallinity of hydroxyapatite nanoparticles

Abstract

Nano-sized hydroxyapatite (HA) particles were prepared by chemical precipitation through aqueous solutions of calcium chloride and ammonium hydrogenphosphate. The influence of temperature, ripening time and calcination on the crystallinity and morphology of the HA nanoparticles were investigated. It was found that the crystallinity and crystallite size increased with the increase of synthetic temperature and ripening time. XRD and TEM results showed that the morphology change of HA nanoparticles was related to their crystallinity. High crystallinity of HA led to regular shape and smooth surface of the nanoparticles. The crystallinity of HA powders increased greatly after calcination at 650 C for 6 h but the change of the crystallite size after calcination was dependent on the crystallinity and crystallite size of ''as prepared'' HA nanoparticles.

Thermal analysis of hydroxyapatite with adsorbed oxalic acid

“…Therefore, mass loss in this range of temperature is larger compared to that for pure hydroxyapatite described by Skwarek et al [19]. In the temperature range 200-950°C, small mass loss results from removal of carbonates and chemically bonded water [20,21]. These data are in agreement with the results obtained by Bianco et al [22].…”

Physiochemical characterizations of hydroxyapatite extracted from bovine bones by three different methods: Extraction of biologically desirable HAp

“…Therefore, different production methods were reported such as mechanochemistry [3,4], ultrasonic irradiation [5], microwave irradiation [6,7], sol-gel [8][9][10][11], chemical precipitation [12,13], hydrothermal method [14][15][16], hydrolysis [17], microemulsion [18][19][20], and emulsion liquid membrane [21]. The synthesized HAp does not have adequate biological properties as the natural apatite existing in bones.…”

Physical, Thermal and Spectral Properties of Biofield Treated 1,2,3-Trimethoxybenzene

“…The result indicated 45.96% increase in the crystallite size of treated compound as compared to the control sample. Pang and Bao reported that due to synthesis temperature and ripening on hydroxyapatite causes an increase in crystallite size [31]. Rey et al [32] and Drouet et al [33] reported an increase in crystal size with increase in temperature and pH.…”