Spectroscopic analysis of blue cobalt smalt pigment

• DOI: 10.1016/j.vibspec.2009.12.005
• Publication Date: 2010-01-15T04:18:24Z
• Authors: D. Jonynaite; J. Senvaitiene; A. Beganskiene; A. Kareiva
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract The method for the determination of SiO 2 in physical mixtures of CoO and SiO 2 or blue cobalt smalt pigment (CoO· n SiO 2 ) by FTIR spectroscopy is suggested. The infrared spectra of all samples were recorded using KBr pellets. It was demonstrated that the characteristic Si–O absorption band at 812 cm −1 could be successfully used as indicator in the evaluation of molar ratio of CoO and SiO 2 in their mixture and pigment CoO· n SiO 2 . The integrated peak area linearly depends on the mole fraction of SiO 2 in the physical mixture of CoO and SiO 2 (in the range of 9.1–50%), and in the cobalt pigment smalt synthesized at 850–900 °C (in the range of 20–50%). Therefore, FTIR spectroscopic evaluation of CoO· n SiO 2 samples provides a possibility to determine the chemical composition of historical cobalt smalt pigments. In addition, the suggested technique is simple, fast and sufficiently accurate.