The aim of this work is to study the effect of the volume of ethanol on the synthesis of hydroxyapatite by sol-gel route. Hydroxyapatite with the chemical formula (Ca5(PO4)3OH) is one of the important biomaterials because of its chemical structure close to the mineral structure of bone and its important biological properties that enable it to be used in medical application as bone replacement 1,2,3. Hydroxyapatite is very used in clinical field as orthopaedic and dental implants as bioactive (high density) and resorbable (porous HA) materials. The bioactive materials form a direct biochemical bonds with living tissues 4-6.
This work is to study the effect of solvent type for the preparation of hydroxyapatite (ethanol and or distilled water ) by sol-gel, using triethyl phosphate ((PO(OC2H5)3): TEP) and calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) as phosphor and calcium precursors, respectively. A mixture of distilled water and pure ethanol with different volumes were used as solvent with total volume of 40 ml. Each prepared solution was aged in closed Teflon container at a temperature of 90 °C for one day except one sample was aged for two days. The gelling and drying time was 1 day for each process. All dried gels were calcined at 700 °C for one hour. Different analyses were used in order to follow the structural alterations of formed phases with type of solvent, such as: X- ray diffraction (XRD, Infrared spectroscopy, Raman and the dielectric analyses.
X-ray patterns of the prepared samples showed the formation of two phases: HA as a main phase and CaO as second phase for all samples. It was observed that the peak intensity of the CaO increases when the amount of water decreases and the intensity of the HA peaks decreases only for the sample DW5ETH35_1D which was prepared in solvent composed of mixture of 5 ml distilled water and 35 ml ethanol . For this sample, the peak intensity of CaO decreases and the intensity of the HA peaks intensity increases. For the sample aged for 2 days, it was observed the formation of - tricalcium phase as secondary phase.
The FT-IR spectra of HA samples at 700 C confirms the presence of phosphate(PO-34) in all spectra, but there is a difference in the intensity and width of the absorption band, It gets narrower as the amount of water decreases, This is confirmed by the results of the X-ray. Also, the dielectric properties were measured in order to compare between the prepared samples. The obtained results showed that the volume of ethanol affect the ratio of HA in the prepared powders.
Citation
Fatima Zohra MEZAHI ,
Amira Mokrane ,
,(2024-07-04), Structural alterations of sol-gel derived hydroxyapatite versus the volume of ethanol,7th International Conference on Smart Materials and Spectroscopy (SMS’2024),Monastir, Tunisie
