The effect of microwave and conventional heating on a modified sol-gel derived biphasic calcium phosphate

A facile sol-gel method was used to synthesize either hydroxyapatite (HA) or beta-tricalcium phosphate (beta-TCP) as the major phase. Herein, we report, on the one hand, the effect of a very low maturation temperature on the final powder composition after drying step, and on the other hand, we compare the effect of calcination of this powder by microwave or electric furnace. It was found that microwave heating has led to the formation of hydroxyapatite phase upon 180 degrees C for 20 minutes, however, XRD patterns show that the powder becomes less crystallized upon 220 degrees C and amorphous upon 230 degrees C. In contrast, furnace heating at 600 degrees C and 700 degrees C converts the as-synthesized powder to beta-TCP as the major phase together with HA as the minor phase. This work shows the possibility to obtain the as-prepared BCP at much lower maturation temperature; it also gives an insight into the role, of either microwave or conventional heating, in controlling the ratio between HA and beta-TCP in the sintered powder.