Obtenção de hidroxiapatita obtida via micro-ondas/hidrotermal

Abstract

Hydroxyapatite (HAP) is a remarkable ceramic material, which consists of calcium, phosphorus and oxygen, with important applications in the medical and environmental field in the removal of heavy metals from soil and water. It presents key characteristics to act as bioceramics which is its main application, in addition to biocompatibility has bioactivity, having great interaction with body tissues. From an environmental aspect, its composition enables adsorption in the presence of various elements such as heavy metals, being applied for removing those from the environment. This paper presents an alternative synthesis route, which is the microwave/hydrothermal synthesis. The synthesis may be initiated by various precursors, in this work the source of calcium used was taken from quail egg shell, which is an industrial residue. The solution is heated and put into pressure greater than atmospheric, causing an increase in nucleation rate of the ceramic powder. In addition to the energy savings produced due to the time saved, the system produces compounds of high purity and controlled morphology. Through spectroscopic analysis in the infrared and X-ray diffraction, it can be proven the formation of hydroxyapatite phase, the lowers intervals of synthesis are related to higher intensities of peaks, which are related to impurities. With the scanning electron microscopy it was verified the production of lamellar particles using acid via and bats for basic via, being the bats with average size close to 4 µm. It has been proven that hydroxyapatite synthesis may be achieved by both routes without the presence of other phosphates phases. It can be noticed that the acidic reactions are more efficient in producing hydroxyapatite with higher purity.