Biomimetic synthesis of hydrophobic calcium carbonate nanoparticles via a carbonation route

✍ Scribed by Chengyu Wang; Ping Xiao; Jingzhe Zhao; Xu Zhao; Yanhua Liu; Zichen Wang

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 578 KB
• Volume: 170
• Category: Article
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2006.08.016

✦ Synopsis

A carbonation route for synthesizing hydrophobic CaCO 3 nanoparticles was described via an organic substrate inducing process. In this study, the synthesized octadecyl dihydrogen phosphate (C 18 H 37 OPO 3 H 2 ) associated with Ca 2+ by means of molecular recognition and induced the nucleation and growth of CaCO 3 . The CaCO 3 nanoparticles were prepared by carbonation of a mixture of Ca(OH) 2 and C 18 H 37 OPO 3 H 2 with CO 2 /N 2 gas mixture. The particle sizes and morphology of the resulting samples were characterized by transmission electron microscopy (TEM). The results indicated that the spindle-like CaCO 3 particles with a mean diameter less than 100 nm were prepared in our study. Fourier transform infrared spectroscopy (FT-IR) analysis revealed that the organic substrate associated with CaCO 3 based on the appearance of P-O symmetric stretching vibrations at 1077 and 578 cm -1 . The CaCO 3 nucleated in the presence of organic substrate exhibited different endothermic peak compared to one nucleated in the absence of organic substrate in different temperature and thermal gravimetric analysis (DTA-TG). The X-ray diffraction (XRD) result revealed that the particles obtained in this study were calcite. In order to observe the effect of the concentration of organic substrate on the morphology, size and hydrophobic property of CaCO 3 , the concentration of organic substrate was increased from 0.25 (m/v) to 1.00 (m/v).