Organo-intercalation Of Sericite And Nanoscale Layered Silicate Platelet's Preparation

Sericite is a kind of important industrial mineral raw material. The organo-intercalation products and nano-scale layered silicate platelet of sericite can meet various needs of multi-level not only through maximizing fine attributes of sericite, but also through adding new features and overcoming some negative factors of its own. It is an important way to improve the value and achieve high-end applications, and also the most promising direction for further development.Based on the structure modified sericite through heat activation, acid-treatment, and Na-exchange, organo-intercalation of sericite was studied in this dissertation. And on this basis preparation of nano-scale layered silicate platelet of sericite was also studied. Afterward, the products and the process mechanism were discussed.The effect of intercalation agents such as dimethyl sulphoxide (DMSO, short chain) and cetyltrimethylammonium bromide (HDTMAB, long chain) were studied. According to the result, HDTMAB was selected as the intercalation agent. Experiments showed that optimum process conditions of organo-intercalation were: addition amount of HDTMAB 150% of CEC value of sericite, dosage of butanol solution 200% of HDTMAB, reaction temperature 80℃and reaction time 6h. After intercalation, the interlayer spacing of sericite increases from 1.0nm to 2.2nm, some even increases to 6.7nm, the maximum percentage of intercalation reaction reached 49.09%.The intercalation compounds had been treated under ball milling and sonication, trying to exfoliate organo-intercalated sericite. The experiment results showed that both of the methods can be used to prepare nano-scale layered silicate platelet of sericite. The optimum process conditions of ball milling were summarized as follows: addition amount of balls 10 times of the raw material, dosage of water 3 times of the raw material, agitation speed of the ball mill 580r/min, and reaction time 3h. The crystal grain size after ball milling and sonication are 16.6nm and 8.1nm, respectively. The interlayer spacing of sericite increases from 1nm to 2nm, some even increases to 6nm.The properties of the intercalation compounds were characterized. The surface property of organo-intercalated compounds had changed into hydrophobic, the contact angle was increased and the surface energy was decreased. HDTMAB tilted in the interlayer and the angle of inclination as 32.63°, and maximum adsorption was 8.72%.