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Nature of flocculation and tactoid formation in montmorillonite: the role of pH.

Segad, M; Åkesson, Torbjörn LU ; Cabane, B and Jönsson, Bo LU (2015) In Physical Chemistry Chemical Physics 17(44). p.29608-29615
Abstract
The dissolution and swelling properties of montmorillonite at different pH have been studied, using small angle X-ray scattering (SAXS), imaging and osmotic stress methods combined with Monte Carlo simulations. The acidity of montmorillonite dispersions has been varied as well as the counterions to the net negatively charged platelets. At low pH, Na montmorillonite dissolves and among other species Al(3+) is released, hydrated, polymerized and then it replaces the counterions in the clay. This dramatically changes the microstructure of Na montmorillonite, which instead of having fully exfoliated platelets, turns into a structure of aggregated platelets, so-called tactoids. Montmorillonite dispersion still has a significant extra-lamellar... (More)
The dissolution and swelling properties of montmorillonite at different pH have been studied, using small angle X-ray scattering (SAXS), imaging and osmotic stress methods combined with Monte Carlo simulations. The acidity of montmorillonite dispersions has been varied as well as the counterions to the net negatively charged platelets. At low pH, Na montmorillonite dissolves and among other species Al(3+) is released, hydrated, polymerized and then it replaces the counterions in the clay. This dramatically changes the microstructure of Na montmorillonite, which instead of having fully exfoliated platelets, turns into a structure of aggregated platelets, so-called tactoids. Montmorillonite dispersion still has a significant extra-lamellar swelling among the tactoids due to the presence of very small nanoplatelets. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
17
issue
44
pages
29608 - 29615
publisher
Royal Society of Chemistry
external identifiers
  • pmid:26477672
  • wos:000364639700020
  • scopus:84946763339
ISSN
1463-9084
DOI
10.1039/c5cp04007h
language
English
LU publication?
yes
id
985db844-faf9-4ab2-8059-c5ad32efcf63 (old id 8149054)
date added to LUP
2015-11-16 14:28:37
date last changed
2017-08-06 03:07:46
@article{985db844-faf9-4ab2-8059-c5ad32efcf63,
  abstract     = {The dissolution and swelling properties of montmorillonite at different pH have been studied, using small angle X-ray scattering (SAXS), imaging and osmotic stress methods combined with Monte Carlo simulations. The acidity of montmorillonite dispersions has been varied as well as the counterions to the net negatively charged platelets. At low pH, Na montmorillonite dissolves and among other species Al(3+) is released, hydrated, polymerized and then it replaces the counterions in the clay. This dramatically changes the microstructure of Na montmorillonite, which instead of having fully exfoliated platelets, turns into a structure of aggregated platelets, so-called tactoids. Montmorillonite dispersion still has a significant extra-lamellar swelling among the tactoids due to the presence of very small nanoplatelets.},
  author       = {Segad, M and Åkesson, Torbjörn and Cabane, B and Jönsson, Bo},
  issn         = {1463-9084},
  language     = {eng},
  number       = {44},
  pages        = {29608--29615},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Nature of flocculation and tactoid formation in montmorillonite: the role of pH.},
  url          = {http://dx.doi.org/10.1039/c5cp04007h},
  volume       = {17},
  year         = {2015},
}