Preparation And Stability Of Kaolinite Intercalation Compound

Kaolinite is an important inorganic non-metallic mineral resource,which has been widely used in plastics,ceramics,rubber,environmental management and other fields.However,the purely natural kaolinite has a lower utilization value.By intercalating kaolinite,the thickness of the sheet becomes thinner,which improves the diameter ratio and surface area of the kaolinite.The composites by intercalation will have some special changes that the original ore does not have,so that it can be applied to more fields and can be used more effectively.This paper mainly studies the intercalation of kaolinite by organic small molecular compounds(potassium acetate,urea,dimethyl sulfoxide,hydrazine,formamide)and organic macromolecular compounds(stearic acid,dodecylamine,cetyltrimethylammonium chloride).to explore the influence of temperature,intercalation time,concentration,pH and other factors on the preparation of kaolinite intercalation composites;At the same time,the stability of the intercalated composites prepared by it was studied,focusing on the stability of water,ethanol and temperature.According to the results of infrared spectroscopy(IR),the intercalated molecules enter the kaolinite layer and bond with the hydroxyl and siloxy groups on the inner surface to form hydrogen bonds,while the intercalation process has little effect on the internal hydroxyl.By studying the effects of intercalation time,temperature,pH and other factors on the preparation of intercalated composites,it was found that in the initial stage of intercalation of organic molecular compounds,the intercalation rate is fast and the intercalation rate is high,with the increase of the intercalation time,the rate of intercalation increase is getting weaker,and even the intercalation rate will decrease The optimum temperature for potassium acetate,dimethyl sulfoxide and kaolinite intercalation is 60 ° C and 120 ° C,respectively.The optimum pH values for potassium acetate,stearic acid and kaolinite intercalation are 9,5.The intercalated composites prepared by intercalation of organic small-molecule have a fixed interlayer spacing,while organic macromolecular compounds may vary in a certain range due to different intercalation conditions.The distance between the layers of the composite prepared by methanol,stearic acid and kaolinite ranges from 0.91 nm to1.01 nm and 3.89 nm to 4.31 nm,respectively.Through washing,exposing into air and placing the prepared compounds in different temperature conditions,The kaolinite intercalation composite prepared by potassium acetate,urea and strontium can be stably present in anhydrous ethanol.The water washing has great damage to the structure of the composite,and the kaolinite-formamide intercalation complex can be stably present in water and acetone.Among them,its stability is high;The structure of the kaolin-hydrazine intercalated complex is damaged by long-term exposure to air..The intercalation composite prepared by urea,potassium acetate and kaolinite can exist stably under the temperature of less than 200 °C,and the structure of kaolinite-dimethyl sulfoxide intercalation composite is lower than 150 °C,its structure will not be affected.The layer spacing of the Kaolin-methanol intercalated complex decreases with the increase of temperature and heating time,and the diffraction peak moves to a high angle direction.