Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (05): 717-722.doi: 10.3866/PKU.WHXB20070518

• ARTICLE • Previous Articles     Next Articles

Structural Characterization and Thermal Decomposition Behavior of Microsized and Nanosized CaCO3

TANG Yan-Jun; LI You-Ming; SONG Jing; PAN Zhi-Dong   

  1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, P. R. China; College of Material Science and Engineering, South China University of Technology, Guangzhou 510640, P. R. China
  • Received:2006-09-29 Revised:2006-11-24 Published:2007-04-28
  • Contact: LI You-Ming E-mail:pperc@scut.edu.cn

Abstract: The surface organic modification of nanosized CaCO3 with palmitic acid was carried out. The prepared samples were characterized by SEM, TEM, XRD, FTIR, and TG-DTG techniques. A comparative study on the crystal structure and thermal decomposition characteristics of nanosized CaCO3, modified nanosized CaCO3, and microsized CaCO3 was made. According to the spectra of FTIR, it was inferred that the chemical binding and the physical adsorption between palmitic acid and nanosized CaCO3 have happened during the modification reaction. The results also revealed that the infrared absorption peaks of C—O bond of modified and unmodified nanosized CaCO3 shifted to a higher frequency by 35 cm-1 compared with that of microsized CaCO3. The mechanism of blue shift in nanosized CaCO3 was discussed, and it was believed that crystalline electric field effect and size effect influenced their infrared spectra. TG-DTG analysis showed that nanosized CaCO3, modified nanosized CaCO3, and microsized CaCO3 decomposed at 735.0, 764.7, and 775.6 ℃, respectively. The decrease of the decomposition temperature was supposed to be related to the lattice expansion and crystallographic deformation of nanosized CaCO3.

Key words: Nanosized CaCO3, Surface modification, Lattice dilatation, FTIR, Thermal decomposition

MSC2000: 

  • O647