Rapid modification of montmorillonite with novel cationic Gemini surfactants and its adsorption for methyl orange

Abstract

A rapid method was developed to prepare organic montmorillonite (organo-MMT) using three novel Gemini surfactants by microwave irradiation of 1 h, which was more effective than conventional heating method of 8–48 h. The structure and morphology of organo-MMTs were characterized by XRD, FT-IR, TEM and SEM. The adsorption amount of Gemini surfactants on MMT and the thermal stability of organo-MMTs were investigated by thermogravimetric analysis (TGA). The results indicated that Gemini surfactants were more efficient than cetyltrimethyl ammonium bromide in the modification of MMT, the organoclays obtained by microwave irradiation method had larger layer spacing than those from traditional heating method. And with the increase of the dosage and chain length of Gemini surfactants, the amount of the intercalary or adsorbed surfactant on the organoclay gradually increased, whereas the thermal stability weakened appropriately. Besides, the adsorption results for methyl orange indicated that all organo-MMTs displayed more excellent adsorption capacities than unmodified MMT. The amount of methyl orange adsorbed onto the organo-MMTs increased proportionately with the increase of the amount or the chain length of Gemini surfactants. This study affords a rapid and efficient method to obtain the organoclay with large interlayer distance and strong adsorption capacity.