Erfani Maryam, Saion Elias, Soltani Nayereh, Hashim Mansor, Abdullah Wan Saffiey B Wan, Navasery Manizheh
Department of Physics, Faculty of Science, University Putra Malaysia, 43400UPM Serdang, Selangor, Malaysia.
Int J Mol Sci. 2012 Nov 8;13(11):14434-45. doi: 10.3390/ijms131114434.
Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Thermogravimetry (TGA). The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB(2)O(4)) nanoparticles and tetraborate (CaB(4)O(7)) nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.
硼酸钙纳米颗粒通过简便的共沉淀热处理方法合成。研究了退火温度和退火时间的差异及其对纳米颗粒晶体结构、粒径、尺寸分布和热稳定性的影响。通过X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、透射电子显微镜（TEM）和热重分析（TGA）对硼酸钙化合物的形成进行了表征。XRD图谱显示，在700℃退火3小时的共沉淀样品形成非晶结构，仅在退火5小时后才转变为晶体结构。结果发现，在900℃退火的样品主要是偏硼酸盐（CaB₂O₄）纳米颗粒，而四硼酸盐（CaB₄O₇）纳米颗粒仅在970℃观察到，这通过FTIR得到证实。TEM图像表明，随着退火时间和温度的增加，平均粒径增大。TGA分析证实了退火样品在较高温度下的热稳定性。
