• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.295-305
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• 2003

This study aims to provide the physicochemical properties of three kinds of organo­smectites which can be diversely used in industries. Some properties of them were compared with Na­smectite. Three kinds of organo­smectites such as Hexadecyltrimethylammonium(HDTMA), Benzyldimethyltetradecylammonium(BDTDA), and Cetylpyridinium(CP) exchanged smectites were manufactured for this study. Three types of organo­smectites showed the alkaline character(pH 9), very low swelling property and viscosity, and a fast flocculation behavior because of strong hydrophobic property in contrast to hydrophilic Na­smectite. Three organo­smectites showed the strong interlayer expansion with basal spacing from $19\AA$ to $23\AA$ compared with the Na­smectite of about 12 $\AA$. Organic cations such as HDTMA, BDTDA, and CP exchanged into smectite were completely decomposed in the temperature range from $250^{\circ}C$ to $400^{\circ}C$. Generally, three organo­smectites showed the similar mineralogical, physicochemical and thermal properties. But their properties are quite different from Na­smectite. Considering economically, CP exchanged smectite would be used for the diverse utilization field in the future time.

• Journal of the Mineralogical Society of Korea
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• v.19 no.2 s.48
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• pp.123-128
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• 2006

Beidellite, a member of the dioctahedral smectite group, was synthesized hydrothermally from dickite. Organophilic [DEACOOH]-beidellite intercalation complex was formed by the cation exchange reaction between synthetic Na-beidellite and [DEACOOH]Br. The products dried in high vacuum were treated with various organic solvent such as methanol, ethanol, acetone, ether, acetonitrile and caprolactam in order to determine the swelling behaviour of the prepared complexes. After drying under high vacuum, basal spacing of [DEACOOH]-beidellite shows 15.1 ${\AA}$, and it changed to 19.4, 29.9, 15.9, 16.8, 14.8, 26.5 and 14.8 ${\AA}$ under distilled water, methanol, ethanol, acetone, ether, acetonitrile and caporlactam, respectively. Especially, the characteristics of the intercalation complexes and their swelling behavior of the synthetic beidellite and natural montmorillonite were compared.