Modulated Monoclinic Hydroxyapatite: The Effect of pH in the Microwave Assisted Method

Hydroxyapatite (HAp) is a natural hard tissue constituent widely used for bone and tooth replacement engineering. In the present work, synthetic HAp was obtained from calcium nitrate tetrahydrate (Ca(NO3)2·4H2O) ammonium phosphate dibasic (NH4)2HPO4 following an optimized microwave assisted hydrothermal method. The effect of pH evaluated by addition hydroxide (NH4OH). Hence, different characterization techniques were to determine its influence on resulted powders’ size, shape, crystallinity. By Transmission Electron Microscopy (TEM), it observed that reaction environment modifies morphology HAp, shape evolution, sub-hedral particles at = 7 rod-like nanosized 10, confirmed. Using X-ray Diffraction (XRD) technique, characteristic diffraction peaks monoclinic phase identified. Even if performed Rietveld analysis indicated presence both phases (hexagonal monoclinic), prevails in 95% with average crystallite size about 23 nm. infrared spectra (FTIR) showed absorption bands 3468 cm−1 630 associated OH− hydroxyapatite, 584 cm−1, 960 1090 correspond PO43− CO32− groups. summary, this work contributes obtaining simple soft method has not been previously reported.