Mechanism of Exfoliation of Clays
- School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC 1797 (Australia)
- School of Chemistry, University of New South Wales, Sydney 2052 (Australia)
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.
- OSTI ID:
- 21049331
- Journal Information:
- AIP Conference Proceedings, Vol. 879, 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); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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