Effect of Sensitive pH on Hydroxyapatite Properties Synthesized from Chicken Eggshell

Abstract

The hydrothermal method has effectively synthesized hydroxyapatite (HA). This study aimed to analyze the effect of pH on the properties (purity, crystallinity, and size) of HA crystals. HA synthesis of chicken eggshells was carried out using the hydrothermal method at temperatures of 230 °C with pH 9 and 9.34. The characteristics of HA are determined by XRF, XRD, FTIR, and TEM. The composition of the most significant compound obtained from the results of XRF analysis is CaO (97.5%). The XRD analysis showed that the purity of HA with pH 9.00 and 9.34 obtained was 97.8 and 96.6%, with the crystallinity of 56.46 and 56.96%. It was also obtained that the size of crystal HA was 21.8 and 15.7 nm for samples synthesized at pH 9.00 and 9.34. The results showed that the purity and size of HA were affected by differences in the pH synthesis and were relatively the same for its crystallinity which directly affects the value lattice parameter. The properties of HA produced by the hydrothermal method have met the criteria for biomedical applications.

How to Make and Characterize Hydroxyapatite from Eggshell Using the Hydrothermal Method: Potential Insights for Drug Delivery System

“…Chicken eggshell waste is used because it is easy to obtain, and the calcination results contain a fairly high calcium oxide (CaO) content (97.50%) (Irwansyah et al, 2022). The chicken egg shells are washed with water and dried to remove any adhering dirt.…”

Hydrothermally Synthesized Hydroxyapatite-Silica Composites with Enhanced Mechanical Properties for Bone Graft Applications

“…The generated protons will subsequently neutralize the hydroxyl ions [15]. The generation of orthosilicic is also known to give biological and potential therapeutic effects [16], which can be very beneficial for applying HAS-based materials such as bone Interestingly, the addition of silica can reduce the pH. With the higher content of SiO 2 , the pH returns closer to that of its original base materials, probably due to the formation of orthosilicic acid (H 4 SiO 4 ) from the hydrolysis of SiO 2 .…”

“…The generated protons will subsequently neutralize the hydroxyl ions [15]. The generation of orthosilicic is also known to give biological and potential therapeutic effects [16], which can be very beneficial for applying HAS-based materials such as bone grafts. This trend is also followed by its mass loss of HA, which shows highly stable HAS with a higher content of SiO 2 .…”

“…Hydrothermal synthesis enables the alteration of nanoparticles' surface properties by appropriately selecting surface-coating agents, transforming them from hydrophilic to hydrophobic [15]. The visibility of pH sensitivity will be enhanced when observing the effect within a narrow optimal pH range, minimizing the difference between the values [16]. Previously, a composite prepared through sonochemistry from an onyx crystal with an HA-to-SiO 2 ratio of 80:20 resulted in a crystal size of 30.57 nm with a Vickers hardness of 26.72 HV [17].…”