A Mild and Efficient Biomimetic Synthesis of Rodlike Hydroxyapatite Particles with a High Aspect Ratio Using Polyvinylpyrrolidone As Capping Agent

Abstract

Rodlike hydroxyapatite (HAp) nanoparticles were synthesized at 60 °C through a biomimetic pathway from Ca(NO 3 ) 2 • 4H 2 O, H 3 PO 4 , and NH 4 OH. The polymer polyvinylpyrrolidone (PVP) as a capping agent was used to regulate the nucleation and crystal growth of HAp crystal. X-ray diffraction results combined with high-resolution transmission electron microscopy indicated that single phase, nanocrystal HAp powder could be obtained in one-step and the addition of PVP facilitated the preferential growth of nanocrystal HAp along the <002> axis. The formation mechanism of rodlike HAp crystal and the effects of PVP on the crystal nucleation and growth were discussed based on transmission electron microscopy and Fourier transform infrared spectroscopy results.

Effect of temperature on morphology of triethanolamine-assisted synthesized hydroxyapatite nanoparticles

“…09-0432 for HA (33 %) reveals that the relative intensity of the d 002 XRD peaks of the prepared samples gain a substantial increase. This observation indicates that crystal growth occurs along the [001] direction (i.e., along the c-axis) under the present preparation conditions (Zhang and Lu 2008).…”

“…2 it can be noted that the FTIR peaks for hydroxyl group in samples HAPRT, HAP50, HAP80 and HAP100 are, respectively, positioned at 3,565, 3,568, 3,570, and 3,571 cm -1 . It can also be noted that the peak position of hydroxyl group in HA samples are blue-shifted with respect to standard FTIR absorption value (3,570 cm -1 ) (Zhang and Lu 2008). This shift, which may have originated from the hydrogen bond between -OH group in TEA and O-H at the surface of HA crystal, is higher for HAP-RT, and gradually decreases as the reaction temperature increases.…”

“…Additional bands at 604, 578 and 563 cm -1 in the low wavenumber region represent the triply degenerated bending modes of the O-P-O bond (t 4 ) (Puvvada et al 2010;Sonju Clasen and Ruyter 1997). The observed peak in the region between 3,565 and 3,571 cm -1 and the weak band at 632 cm -1 can, respectively, be assigned to the stretching (t s ) and librational modes (t L ) of the structural hydroxyl anions in HA samples (Zhang and Lu 2008). The spectra also show two weak peaks at 2,866 and 2,980 cm -1 , characteristic of -CH 2 group, indicating the presence of TEA in the dried HA samples.…”

Synthesis and characterization of poly(4-vinyl pyridine-co-styrene)/FHAP nanocomposite, and its biomedical application

“…A distinctive resonance peak appears at 0.050 ppm in Fig. 7 for the nano FHAp (Zhan et al 2005;Zhang and Mild 2008;Zhang et al 2003). After the development of PVPCS/FHAp nanocomposites, the 31 P characteristic peak moves to 1.902 ppm as shown in Fig.…”

“…The band that appeared at 604 cm -1 corresponds to O-P-O bending and m 1 symmetric P-O stretching modes (Ma et al 2006). The m 1 symmetric stretching mode of phosphate group is observed at 882 cm -1 (Zhang and Mild 2008). The observed band at 1,367 cm -1 is due to the stretching mode of carbonate, which may be due to the acquisition of air during mineral precipitation (Bertinetti et al 2007).…”