Synthesis of calcium phosphate: Influence of sintering temperature on the formation of fluorhydroxyapatite

Abstract

Calcium phosphate biomaterials can be classified as polycrystalline ceramics. Hydroxyapatite is one kind of calcium phosphate biomaterials which is also a mineral component in hard tissue, especially dental and bones. Hydroxyapatite has low chemical stability at high temperatures and low durability in an acidic environment. On the other hand, fluorhydroxyapatite has good chemical stability at high temperatures as well as the nature of its bioactivity. Fluorhydroxyapatite is made by adding F to replace some OH functional groups in hydroxyapatite. In this research, fluorhydroxyapatite was synthesized through precipitation method and microwave assistant with sintering temperatures of 600°C, 800°C, and 1000°C. Based on the characterization using an x-ray diffractometer, the results showed that at 1000°C sintering temperature, the samples have a higher intensity of fluorapatite and fewer impurities than other samples sintered at 800°C and 600°C. Fourier Transform Infra-Red (FTIR) analysis shows that similar functional groups appeared in the samples with all sintering temperatures. Conductivity evaluation shows that the conductivity values of the samples were inversely proportional to the sintering temperatures. The morphology of the samples not so clearly seen due to agglomeration, but it can be observed that fluorhydroxyapatite is flat-shaped needle-like or rod-shaped.