Authors

Abstract

Calcium hydrogen phosphate dihydrate (CaHPO4.2H2O, CHPD) or brushite crystal is a well known urinary substance found frequently in urinary stones. The CHPD crystals have been crystallized in sodium metasilicate gel (SMS) at room temperature under pH 6 in the presence of sodium fluoride. Here, H3PO4 and CaCl2 were used as reactants which resulted in simultaneous crystallization of mostly dentritic brushite crystals and a small quantity of hydroxyapatite (HA). On the other hand, use of Na2HPO4 and CaCl2 as reactants yielded the large quantity of HA along with platelet brushite crystals. In both the cases, addition of sodium fluoride is found to inhibit the nucleation and subsequent growth of brushite crystals. The crystal morphology, structure and elemental composition of the grown crystals have been analyzed using SEM-EDX and powder XRD studies. Functional groups present in the grown crystals have been confirmed from the vibrational frequencies of the recorded FTIR spectrum.

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