Nanocrystalline hydroxyapatite prepared under various pH conditions.

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Nanotechnology

Background:

• Hydroxyapatite (HAP) exhibits excellent biocompatibility and structural similarity to natural bone, making it valuable for biomedical applications.
• The synthesis of HAP often involves chemical precipitation, but controlling its properties like crystallinity and morphology is key.

Purpose of the Study:

• To investigate the influence of pH on the synthesis of hydroxyapatite (HAP) using chemical precipitation assisted by ultrasonic irradiation.
• To characterize the resulting calcium phosphate compounds synthesized under different pH conditions (7, 9, and 11).

Main Methods:

• Chemical precipitation using calcium nitrate tetrahydrate and diammonium hydrogen phosphate.
• Ultrasonic irradiation technique to assist synthesis.
• Addition of 5% polyethylene glycol (PEG600) as a surfactant.
• Characterization using Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM).

Main Results:

• Nanocrystalline hydroxyapatite was successfully synthesized.
• The formation of HAP was confirmed to be pH-dependent.
• Optimal nanocrystalline HAP formation was observed at pH levels above 9.

Conclusions:

• pH is a critical parameter in the ultrasonic-assisted chemical precipitation of hydroxyapatite.
• Synthesizing HAP at pH 9 and 11 yields nanocrystalline structures suitable for biomedical applications.
• This method offers a controlled approach to producing biocompatible HAP nanomaterials.