Hydrolysis of dicalcium phosphate dihydrate in the presence or absence of calcium fluoride.
Effects of temperature (25 and 37 degrees C), pH (4.9-10.5), and CaF2 on CaHPO4.2H2O (DCPD) hydrolysis were studied in a pH-stat. Octa-calcium phosphate (OCP) was the product at pH 6.2-6.8 and 25-37 degrees C; thermodynamically stable apatitic compounds were formed at higher pH and/or higher temperature. In the presence of CaF2, apatite was the product, its crystallinity improved, and the fluoride content increased as pH of the reaction decreased. The results demonstrate the remarkable ability of fluoride to promote the hydrolysis of an acidic calcium phosphate, DCPD, to apatite.
D001031:Apatites; D002124:Calcium Fluoride; D002130:Calcium Phosphates; D055598:Chemical Phenomena; D002621:Chemistry; D003460:Crystallization; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D006878:Hydroxides; D007700:Kinetics; D011188:Potassium; D017680:Potassium Compounds; D013696:Temperature
D001031:Apatites; D002130:Calcium Phosphates; D006878:Hydroxides; D017680:Potassium Compounds; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous; D002124:Calcium Fluoride; D011188:Potassium; C029943:potassium hydroxide