Synthesis and Characterization of Magnesium Trisilicate by Reverse Strike Method
|School||Beijing University of Chemical Technology|
|Keywords||Trisilicate Titration order Hydrous magnesium silicate Nitrogen adsorption Pore ??structure The surface acid active sites Adsorption properties|
By Na 2 O · nSiO 2 and Mg ( NO 3 < / sub > ) 2 sub > three precipitated synthetic silicate magnesium. Using XRD, IR, TG / DTA, BET, pyridine adsorption and Asian methyl blue adsorption and other characterization means , examine the order of the feedstock , acidification and calcining process of sample crystallinity degree of surface functional groups , surface texture , pore structure , surface acidity and adsorption the performance impact of the law and its impact mechanism . The results showed that the the , different titration sequence and different activation methods obtained samples are amorphous substances . Titration sequence texture on the surface of the sample had a significant effect , the pore size of the respective samples showed a multimodal distribution of Mg ( NO 3 < / sub >) 2 sub > was added dropwise Na 2 < / sub> O the nSiO 2 sub > sample solution synthesis of microporous materials below 3 nm pore surface area up to 568.93 m 2 sup > · g -1 sup>, hydrous magnesium silicate content . Na 2 O · nSiO 2 was added dropwise to Mg (NO 3 ) 2 sample solution synthesis big hole material 179.40m 2 sup> · g -1 sup>, a specific surface area of ??reduced content of hydrous magnesium silicate . Improve the degree of crystallinity of the sample was calcined , the expansion of the sample bore , in the hole content increased , the surface texture tends to stabilize , the formation of mesoporous materials . Acid treatment so that the Mg 2 sup > H sup> , formed on the surface of the silicon hydroxyl groups surface texture tends developed , disappear ultramicropore , the material in the hole , there is a small number of large holes . Calcination and acidification can improve the surface of the sample of the total amount of acid and B acid and L acid reduction . Methylene blue adsorption amount of each sample surface texture law is not exactly the same , indicating that the pore structure is not the only factor to affect the adsorption properties of the sample , the type of acid active sites , the number of samples as well as strong and weak on adsorption properties have a certain impact .