- Conference date: 23–26 February 2011
- Location: Chandigarh (India)
Hydroxyapatite (HAP) ceramics have been recognized as substitute materials for bone and teeth in orthopedic and dentistry field due to their chemical and biological similarity to human hard tissue. The nanosized and nanocrystalline forms of HAP have great potential to revolutionize the hard tissue‐engineering field, starting from bone repair and augmentation to controlled drug delivery systems. This paper reports the synthesis of biomimetic nano‐hydroxyapatite (HAP) by sol‐gel method using calcium nitrate tetrahydrate (CNT) and potassium dihydrogen phosphate (KDP) as calcium and phosphorus precursors, respectively to obtain a desired Ca/P ratio of 1.67. Deionized water was used as a diluting media for HAP sol preparation and ammonia was used to adjust the pH to 11. After aging, the HAP gel was dried at and sintered to different temperatures ( and ). The dried and sintered powders were characterized for phase composition using Fourier transform infrared (FTIR) spectroscopy and X‐ray diffraction (XRD). The particle size and morphology was studied using transmission electron microscopy (TEM). The thermal behavior of the dried HAP nanopowder was studied in the temperature range of to using thermal gravimetric analyser (TGA). The BET surface area of absorbance was determined by Nitrogen adsorption using Brunauer‐Emmett‐Teller (BET) method. The presence of characteristic peaks of the phosphate and OH groups in FTIR spectrums confirmed the formation of pure HAP in dried as well as sintered powders. XRD results also confirmed the formation of stoichiometric nano‐HAP. Sintering revealed that with increase in temperature, both the crystallinity and crystallite size of nano‐HAP particles increased. The synthesized nano‐HAP powder was found to be stable upto without any additional phase other than HAP, whereas peak of β‐TCP (tricalcium phosphate) was observed at Photomicrograph of TEM showed that the nanopowder sintered at is composed of hydroxyapatite nanoparticles (26.0–45.6 nm), which is well in agreement with the crystallite size calculated using XRD data. TGA study showed the thermal stability of the synthesized nano‐HAP powder. The BET surface area decreased with increase in sintering temperature.
- X-ray diffraction
- Fourier transform infrared spectroscopy
- Transmission electron microscopy
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