Small-angle neutron scattering study of concentrated colloidal dispersions : the electrostatic/steric composite interactions between colloidal particles
Small-angle neutron scattering was used to investigate the interactions in concentrated colloidal dispersions containing silica or polystyrene latex with adsorbed polyethyleneoxide (PEO). In these dispersions of charged particles, both electrostatic and steric repulsions are present. The PEO layer w...
Publié dans: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 22(2006), 14 vom: 04. Juli, Seite 6060-7 |
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Auteur principal: | |
Autres auteurs: | , |
Format: | Article |
Langue: | English |
Publié: |
2006
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Accès à la collection: | Langmuir : the ACS journal of surfaces and colloids |
Sujets: | Journal Article |
Résumé: | Small-angle neutron scattering was used to investigate the interactions in concentrated colloidal dispersions containing silica or polystyrene latex with adsorbed polyethyleneoxide (PEO). In these dispersions of charged particles, both electrostatic and steric repulsions are present. The PEO layer was made invisible to neutrons through contrast matching. The effect of the interparticle repulsion was clearly shown in the scattering spectra by the appearance of a peak at low Q. The effective potentials can be well described by the Hayter-Penfold/Yukawa (HPY) potential. In the silica dispersions studied, the layer thickness is small, hence the electrostatic potential dominates and the potential has a lower concentration dependence. In the dispersions of polystyrene latex, the adsorbed layer is thicker; consequently, the electrostatic potential dominates at low volume fraction (the potential has a lower concentration dependence), and the steric potential dominates at higher volume fraction (the potential has a higher concentration dependence). This study also suggests that when more than one potential is present the stronger one has a dominant influence in determining the structure factor. This finding makes it possible to describe the multicomponential interactions by a single function |
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Description: | Date Completed 03.08.2007 Date Revised 27.06.2006 published: Print Citation Status PubMed-not-MEDLINE |
ISSN: | 1520-5827 |