FT-IR STUDY OF ROCKROSE AND OF CHAR AND ACTIVATED CARBON

Abstract Fourier transform-infrared spectroscopy was used in the study of rockrose ( Cistus ladaniferus , L.) and of rockrose chars and activated carbons. Chars were prepared by heating the starting material between 200 and 1000 °C in nitrogen. Also, a sample was obtained at 600 °C in the atmosphere of the products of the thermal decomposition of rockrose. This charred product was used in the preparation of activated carbons. It was heated at 800 °C in air, CO 2 or steam to 40% burn-off. The presence of oxygen groups and of olefinic and aromatic structures was detected in rockrose. The heat treatment of rockrose in the range 300–500 °C produced the most significant changes in the chemical structure of the material. Olefinic CC bonds and ether structures increased first in the chars and then the aromatic structure developed. Above 500 °C, the oxygen groups decreased with the temperature increase. The charring method of rockrose also influenced markedly the chemical structure of the chars. The use of a greater mass of sample slowed down the pyrolysis of rockrose. The activated carbons possessed aromatic CC bonds and oxygen groups.