Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Clays and Clay Minerals Don't get GSW? Talk to your librarian.
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Clays and Clay Minerals; October 2003; v. 51; no. 5; p. 555-565; DOI: 10.1346/CCMN.2003.0510509
© 2003 Clay Minerals Society
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weiss, Z.
Right arrow Articles by Pospísil, M.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

INTERCALATION AND GRAFTING OF VERMICULITE WITH OCTADECYLAMINE USING LOW-TEMPERATURE MELTING

Zdenek Weiss1, Marta Valásková1, Monika Krístková1, Pavla Capková2 and Miroslav Pospísil2

1 Institute of Materials Chemistry, Technical University Ostrava, 708 33 Ostrava-Poruba, Czech Republic
2 Faculty of Mathematics and Physics, Charles University Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic

* E-mail address of corresponding author: zdenek.weiss{at}vsb.cz

Octadecylamine (ODA) was used to intercalate a fine-grained and a coarse-grained fraction of natural Mg-vermiculite (VER) using a low-temperature melting procedure. Mixtures of Mg-vermiculite fractions and powdered ODA in the molar ratios of 2:1, 1:1, 1:2 and 1:6 were homogenized and heated for 1, 3, 15 and 30 h at 80°C to prepare intercalated samples. X-ray powder diffraction analysis of intercalated samples was combined with molecular modeling to investigate their interlayer structure. Significant amounts of non-intercalated vermiculite and diffuse peaks with very low intensity and basal spacings close to 29 Å were identified when the lowest concentration (molar ratio VER:ODA = 2:1) was used. According to molecular modeling, this indicates the initial stage of a one-layer arrangement of distorted ODA molecules in the interlayer. If the concentration of ODA molecules and treatment time were increased, a two-layer arrangement of ODA molecules with a different ODA chain-disorder and interlayer-space saturation was identified. Interlayer ODA molecules were inclined to the vermiculite basal plane with an inclination angle for two-layer arrangements that ranged from 76 to 95°. Experimental basal spacings with these two-layer arrangements varied from 52 to 58 Å and were in agreement with molecular modeling results. A fully-saturated 58 Å two-layer ODA arrangement was identified when higher ODA concentrations (VER:ODA = 1:2 and 1:6) and 15 and 30 h treatment times were used. There was no significant difference between ODA-intercalated samples prepared using fine-grained and coarse-grained Mg-vermiculite fractions. A grafted ODA-chain nano-layer with a 49.6(2.1) Å average height was observed on the surface of thin ODA-intercalated micro-flakes using atomic force microscopy. Grafted ODA chains not only created an homogeneous surface nano-layer, but also variable-width channels between the ODA molecules.

Key Words: Atomic Force Microscopy • Intercalation • Low-temperature Melting • Molecular Modeling • Octadecylamine • Vermiculite • X-ray Powder Diffraction






JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Clay Minerals Society