OCP (octacalcium phosphate) crystals are apatite-based crystals with hydrated layers that are utilised to make needle or plate-shaped HAP (hydroxyapatite) nanocrystals in apatite chemistry. The crystals are made through a dissolution precipitation process. These reactions resulted in hexagonal HAP nanocrystals being formed under hydrothermal conditions from OCP at 180°C for 3 hours with the pH of the solution adjusted to 5.5 and the addition of dicarboxylate ions such as succinate (OOC.(CH2)2.COO)2- ions with a Ca/P molar ratio of 1.560.02, while the morphology of OCP was preserved. During the integration of succinate ions in OCP crystals, the hydrogen phosphate (HPO42-) ions in the hydrated layers of OCP are replaced by succinate ions. The crystalline size in the longitudinal direction of various (a,b,c) axes changes depending on the thickness of the laminated plate-shaped HAP crystals since the HAP crystal structure is hexagonal. Here, their size is determined as perpendicular to the (100) plane using Scherrer's equation, D100 = K/ ( cos). SEM, FTIR, and X-ray diffraction studies were used to analyse the organically modified OCP that formed HAP, which has a unique nanostructure with micrometre thickness.
Author(s) Details:
Shiv Prakash Mishra,
Faculty of Science in Chemistry, Dr. Rammanohar Lohia Avadh University,
Ayodhya-224001, (UP), India.
Please see the link here: https://stm.bookpi.org/NICB-V7/article/view/5929
