CHEN Dai-mei¹ , CHEN Jian² , LUAN Xin-long² , JI Hai-peng² , XU Feng ² , LIAO Li-bing²

1. National Laboratory of Mineral Materials , China University of Geosciences , Beijing 100083, China;
2. School of Materials Sciences and Technology , China Univer sity of Geosciences , Beijing 100083, China

Abstract: Sodium stearate modified montmorillonite ( NaSTA-MMT ) was prepared using the anion surfactant, sodium stearate, and its structure was characterized by X-ray and F I-IR diffraction. The results showed that sodium stearate had been intercalated into the interlayers of montmorillonite and the layer spacing was expanded from 1.274 nm to 4.805 nm as the loading concentrations of sodium stearate increased. The adsorption of methylene blue on NaSTA-MMT was also examined. The experiment showed that the kinetic adsorption of methylene blue onto NaSTA-MMT was described best by a pseudo-second-order model and that the adsorption isotherm was in good agreement with the Langmuir equation. The activation energy, enthalpy and entropy of methylene blue adsorption on NaSTA-MMT were estimat ed as 2. 36 kJ/ mol, - 21. 47 kJ/ mol and 44. 45 J/ mol•K, respectively, indicating a physical adsorption process.

Key words: montmorillonite; modification; sodium stearate; adsorption; methylene blue

*Corresponding Author, E-Mail: chendaimei@cugb.edu.cn

Bulletin of Mineralogy, Petrology and Geochemistry Vol. 30, No.2, 2011, page 123-128

(Source from http://www.cnki.com.cn/)