Fabrication of nano structural biphasic materials from phosphogypsum waste and their in vitro applications

• Ratio of HA and β-TCP phases were controlled by thermal treatment.
• HA partially decomposed into β-TCP with other bioactive phases.
• Calcined HA at 900 °C is the best for the bioactivity behavior.

In this study, a novel process of preparing biphasic calcium phosphate (BCP) is proposed. Also its bioactivity for the utilization of the prepared BCP as a biomaterial is studied. A mixture of calcium hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) could be obtained by thermal treatment of HAP which was previously prepared from phosphogypsum (PG) waste. The chemical and phase composition, morphology and particle size of prepared samples was characterized by X-ray diffraction (XRD), Infrared spectroscopy (IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The bioactivity was investigated by soaking of the calcined samples in simulated body fluid (SBF). Results confirmed that the calcination temperatures played an important role in the formation of calcium phosphate (CP) materials. XRD results indicated that HAP was partially decomposed into β-TCP. The in vitro data confirmed that the calcined HAP forming BCP besides other phases such as pyrophosphate and silica are bioactive materials. Therefore, BCP will be used as good biomaterials for medical applications.

(a) Schema of the process, (b) TEM of nano particles of biphasic materials and (c) SEM of post-immersion.Figure optionsDownload as PowerPoint slide