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Title: Size effects of exchange cation on the pore structure and surface fractality of montmorillonite

Abstract

Ca-montmorillonites were exchanged with both metal cations (manganese and copper) and organic cations (tetramethylammonium (TMA) and hexadecyltrimmethylammonium (HDTMA)) to study the cation size effects on the pore structure and surface roughness of montmorillonite based on the classical and fractal analysis of their nitrogen adsorption isotherms. The surface fractal dimension D was calculated from their nitrogen isotherms with the aid of the recently proposed Neimark equation. The decrease of BET surface area of montmorillonite induced by the larger size of exchange cation was interpreted with both the coverture of some surface roughness (surface screening effect) and the inhibition of nitrogen molecule into some pores (pore blocking effect). The pore blocking effect was examined with the changes of mean pore size. Meanwhile, the D value was used to examine whether or not the surface screening effect existed. It was concluded that the combination of classical and fractal analyses of nitrogen isotherms may facilitate understanding of the evolution of pore and surface structures of clay exchanged with different cations.

Authors:
; ;
Publication Date:
Research Org.:
National Central Univ. (TW)
OSTI Identifier:
20013601
Resource Type:
Journal Article
Journal Name:
Journal of Colloid and Interface Science
Additional Journal Information:
Journal Volume: 217; Journal Issue: 1; Other Information: PBD: 1 Sep 1999; Journal ID: ISSN 0021-9797
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ION EXCHANGE; MONTMORILLONITE; AMMONIUM COMPOUNDS; CALCIUM COMPLEXES; MANGANESE COMPLEXES; COPPER COMPLEXES; PORE STRUCTURE; ROUGHNESS; ADSORPTION ISOTHERMS

Citation Formats

Lee, J.F., Lee, C.K., and Juang, L.C. Size effects of exchange cation on the pore structure and surface fractality of montmorillonite. United States: N. p., 1999. Web. doi:10.1006/jcis.1999.6365.
Lee, J.F., Lee, C.K., & Juang, L.C. Size effects of exchange cation on the pore structure and surface fractality of montmorillonite. United States. doi:10.1006/jcis.1999.6365.
Lee, J.F., Lee, C.K., and Juang, L.C. Wed . "Size effects of exchange cation on the pore structure and surface fractality of montmorillonite". United States. doi:10.1006/jcis.1999.6365.
@article{osti_20013601,
title = {Size effects of exchange cation on the pore structure and surface fractality of montmorillonite},
author = {Lee, J.F. and Lee, C.K. and Juang, L.C.},
abstractNote = {Ca-montmorillonites were exchanged with both metal cations (manganese and copper) and organic cations (tetramethylammonium (TMA) and hexadecyltrimmethylammonium (HDTMA)) to study the cation size effects on the pore structure and surface roughness of montmorillonite based on the classical and fractal analysis of their nitrogen adsorption isotherms. The surface fractal dimension D was calculated from their nitrogen isotherms with the aid of the recently proposed Neimark equation. The decrease of BET surface area of montmorillonite induced by the larger size of exchange cation was interpreted with both the coverture of some surface roughness (surface screening effect) and the inhibition of nitrogen molecule into some pores (pore blocking effect). The pore blocking effect was examined with the changes of mean pore size. Meanwhile, the D value was used to examine whether or not the surface screening effect existed. It was concluded that the combination of classical and fractal analyses of nitrogen isotherms may facilitate understanding of the evolution of pore and surface structures of clay exchanged with different cations.},
doi = {10.1006/jcis.1999.6365},
journal = {Journal of Colloid and Interface Science},
issn = {0021-9797},
number = 1,
volume = 217,
place = {United States},
year = {1999},
month = {9}
}