Study On Modification Of Montmorillonite And Its Application

Montmorillonite is a kind of layered aluminosilicate clay with a wide distribution and abundant storage in nature as well as low cost. Modified montmorillonite is a multifunctional material and has played an important role in environment protection, industry catalysis, medicament and so on. Therefore further study on the modification of montmorillonite will bring out a bright prospect of economical and social benefits. In this work, the main attempts are focused on the montmorillonite modification based on its layered structure and cation exchangeable properties, and the investigation the effect of modification methods, conditions on the structure, properties of montmorillonite. The main contents are as following:(1) Synthesis of solid-acid materials: The solid-acid materials were synthesized by intercalating metallic cations into the gallery of montmorillonite and exchanging with interlaminer cations. The obtained samples have good surface properties, especially high surface acidity. The results show that the surface acidity of the samples is improved obviously by intercalating higher valence metallic cations. Lower concentration of intercalated metallic cation is helpful to synthesize solid acid materials with stronger surface acidity, and the thermal stability of the surface acidity is related to the stability of structure water in montmorillonite.(2) Synthesis of adsorption materials: The polymeric hydroxyl metallic cations with bigger radius were prepared by hydrolysis process using different metallic cations at first, and then were introduced into the gallery of montmorillonite leading to the increase of interlaminar distance, finally modified montmorillonite with larger surface areas and pore volumes were obtained, and its adsorption ability was tested by using orcein dye as model matter. The results indicated that the decolorization rate of orcein dye reached to 97% in shorter time and less dosage, therefore modified montmorillonite is a good adsorption material. It was also found that modified montmorillonite showed higher adsorption ability with lager interlayer distance and stronger diffraction peak intensity in 001 plane from X-ray diffraction analysis.