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Title: Mechanism of Exfoliation of Clays

Abstract

The exfoliated structures of lamellar clays offer potentials as precursor for formation of nano-structured materials. We explored the Synchrotron Radiation soft X-ray techniques and nuclear magnetic resonance to study the exfoliation of phyllosilicate clays by polymers. Experiments were carried out in dispersions containing approximately 1% weight phyllosilicate in 5% aqueous solution of poly(acrylic acid) at different temperatures. The clays were exfoliated as the reaction was performed at 85 deg. C. X-ray photoemission spectroscopy indicated that the exfoliated structures were consisted of virtually pure silica nano-plates. 29Si nuclear magnetic resonance and oxygen K-edge near edge X-ray absorption fine structure indicated that the surface of the plates was terminated by high concentrations of the silanol groups, which created structural branches. The formation of the branches created a steric effect that inhibited the stacking of the plates, which eventually resulted in the exfoliation.

Authors:
; ; ; ;  [1];  [2]
  1. School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC 1797 (Australia)
  2. School of Chemistry, University of New South Wales, Sydney 2052 (Australia)
Publication Date:
OSTI Identifier:
21049331
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 879; Journal Issue: 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436382; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACRYLIC ACID; AQUEOUS SOLUTIONS; CHEMICAL ANALYSIS; CLAYS; FINE STRUCTURE; NANOSTRUCTURES; NUCLEAR MAGNETIC RESONANCE; OXYGEN; PHOTOEMISSION; SILICA; SILICON 29; SOFT X RADIATION; SYNCHROTRON RADIATION; X-RAY PHOTOELECTRON SPECTROSCOPY; X-RAY SPECTRA

Citation Formats

Tran, Nguyen, Wilson, Michael, Milev, Adriyan, Dennis, Gary, Kannangara, G. S. Kamali, and Lamb, Robert. Mechanism of Exfoliation of Clays. United States: N. p., 2007. Web. doi:10.1063/1.2436382.
Tran, Nguyen, Wilson, Michael, Milev, Adriyan, Dennis, Gary, Kannangara, G. S. Kamali, & Lamb, Robert. Mechanism of Exfoliation of Clays. United States. doi:10.1063/1.2436382.
Tran, Nguyen, Wilson, Michael, Milev, Adriyan, Dennis, Gary, Kannangara, G. S. Kamali, and Lamb, Robert. Fri . "Mechanism of Exfoliation of Clays". United States. doi:10.1063/1.2436382.
@article{osti_21049331,
title = {Mechanism of Exfoliation of Clays},
author = {Tran, Nguyen and Wilson, Michael and Milev, Adriyan and Dennis, Gary and Kannangara, G. S. Kamali and Lamb, Robert},
abstractNote = {The exfoliated structures of lamellar clays offer potentials as precursor for formation of nano-structured materials. We explored the Synchrotron Radiation soft X-ray techniques and nuclear magnetic resonance to study the exfoliation of phyllosilicate clays by polymers. Experiments were carried out in dispersions containing approximately 1% weight phyllosilicate in 5% aqueous solution of poly(acrylic acid) at different temperatures. The clays were exfoliated as the reaction was performed at 85 deg. C. X-ray photoemission spectroscopy indicated that the exfoliated structures were consisted of virtually pure silica nano-plates. 29Si nuclear magnetic resonance and oxygen K-edge near edge X-ray absorption fine structure indicated that the surface of the plates was terminated by high concentrations of the silanol groups, which created structural branches. The formation of the branches created a steric effect that inhibited the stacking of the plates, which eventually resulted in the exfoliation.},
doi = {10.1063/1.2436382},
journal = {AIP Conference Proceedings},
number = 1,
volume = 879,
place = {United States},
year = {Fri Jan 19 00:00:00 EST 2007},
month = {Fri Jan 19 00:00:00 EST 2007}
}
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