Characterization of in situ prepared nano‐hydroxyapatite/polyacrylic acid (HAp/PAAc) biocomposites

Abstract

Nanoparticles hydroxyapatite (HAp) was prepared via an in situ biomimetic process with polyacrylic acid (PAAc) as a host polymeric material. Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry were used to test the physical and chemical characteristics of biocomposites. The formation of HAp is confirmed by energy dispersion X-ray analysis. Chemical binding between inorganic HAp and PAAc was investigated and discussed. HAp formation was initiated through the interaction of Ca 2þ ions with the negative side groups of the polymer surface. The results showed that the biocomposites were formed with good homogeneity and thermal stability. Nanoparticles of HAp were uniformly distributed in the polymeric matrices. The resulting new materials are hoped to be applicable in the biomedical fields.

Synthesis and Optimization of Colloidal Hydroxyapatite Nanoparticles by Hydrothermal Processes

“…24,30 Stretch bands at 1023 and 1088 cm -1 , as well as the deformation bands at 503, 561 and 600 cm -1 , were observed for the phosphate group (PO 4 3-). 8,42 In addition to the phosphate bands, two bands appeared at 1193 and 868 cm -1 , which can be assigned to the OH in-plane bending and P-(OH) stretching modes of HPO 4 2-groups in the structure, respectively. 30 The presence of base backbone moieties of phosphate and hydroxyl groups along with calcium confirmed the complete synthesis of HA due to the presence of the band at 632 and 3570 cm 43 attributed the narrow band around 3600 cm -1 to O-H stretching in the HA crystalline structure.…”

Preparation, spectroscopic and mechanical studies of nano porous HAp loaded with MWCNTs

“…The analytical reagent grade Calcium nitrate tetra hydrate and Ammonium phosphate dibasic was used as the starting materials. To maintain molar ratio of Ca:P at 1.67(constant) the amount of the precursors were calculated [31]. It is substantial for biological response to produce pure HAp without minor fraction.…”

“…Since the most intense peak in the HAp diffraction pattern at 31.7, the relative intensity of the diffraction at the same Bragg angle (31.7 ͦ ) matches with the relative presence of HAp phase in the blend. The particle size is determined by the Scherrer equation [31]. where t is the crystallite size (nm) and d-is the theoretical density of HAp (3.16 g/cm 3 ).The results suggested that in case of (HAp/PVA) blend the apparent average crystal size is the same by increasing the percentage of the PVA before and after burning.as shown in fig.7a-7bIn case of the presence of MWCNTs the outcomes indicated that the apparent average crystal size increased by increasing the share of the MWCNT beforeburning.as shown in fig.9aBut the opposite occurred after burning as shown in fig 9b where the crystallite size of the HAp/.0003 MWCNT are significantly smaller, with average grain size of 85±29 nm (tab.2).…”

Fabrication of novel phosphotungstic acid functionalized mesoporous silica composite membrane by alternative gel-casting technique

“…The total weight loss at this stage is about 26 wt.%. The transition peaks of third and fourth stages after 300 C are attributed to the cleavage backbone of polymer [62,63].…”