Data from: Effect of reaction solvent on hydroxyapatite synthesis in sol-gel process

Synthesis of hydroxyapatite (HA) through sol-gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorous precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant. 0.5 M aqueous DAHP solution was used in all reactions while CNTH was dissolved in distilled water, tetrahydrofuran (THF) and N,N-dimethylformamide (DMF) at a concentration of 0.5 M. Ammonia solution (28-30%) was used to maintain the pH of the reaction mixtures in 10-12 range. All reactions were carried out at 40±2 °C for 4 h. Upon completion of the reactions, products were filtered, washed, and calcined at 500 °C for 2 h. It was clearly demonstrated through various techniques that the dielectric constant and polarity of the solvent mixture strongly influences the chemical structure and morphological properties of calcium phosphate synthesized. Water based reaction medium, with highest dielectric constant, mainly produced β-calcium pyrophosphate (β-CPF) with a minor amount of HA. DMF/water system yielded HA as the major phase with a very minor amount of β-CPF. THF/water solvent system with the lowest dielectric constant, resulted in the formation of pure HA.