Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Interfacial properties of aggregates formed by cationic polyelectrolyte and anionic surfactant
YKI – Ytkemiska institutet.
YKI – Ytkemiska institutet.
2000 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 16, 1951-1959 p.Article in journal (Refereed)
Abstract [en]

Interactions between mica surfaces across aqueous solutions containing mixtures of a highly positively charged polyelectrolyte and an anionic surfactant were studied using a surface force apparatus. The investigation was carried out using a constant polyelectrolyte concentration (20 ppm) and a wide range of surfactant concentrations (0 - 1 cmc). The chemical composition of the adsorbed polyelectrolyte-surfactant layers was analysed by XPS. The properties of polyelectrolyte-surfactant aggregates formed in bulk were studied by measurements of turbidity and electrophoretic mobility. The aggregates formed at low surfactant concentrations (<0.04 cmc) were positively charged, whereas at higher surfactant concentrations the aggregates carried a net negative charge. It was shown that polyelectrolyte-surfactant aggregates rapidly adsorb on negatively charged mica surfaces regardless of the sign of their charge. At surfactant concentrations up to 0.01 cmc, the polyelectrolytes adsorb on mica surfaces with loops and tails stretching out into solution and repulsive steric forces are generated. The thickness of the layer decreases with time and we suggest that this conformational change is accompanied by some expulsion of surfactant >from the adsorbed layers. Thick adsorbed layers were formed in the surfactant concentration range 0.02 - 0.1 cmc. In this concentration regime the measurement of equilibrium forces was inaccessible due to a very slow layer relaxation. During compression the forces were repulsive and during separation an attraction developed. We attribute this to formation of interlayer surfactant bridges. Finally, at high surfactant concentrations (≥ 0.4 cmc) highly negatively charged aggregates adsorb on the surfaces in rather thin layers, resulting in purely repulsive forces of mixed electrostatic and steric origin.

Place, publisher, year, edition, pages
2000. Vol. 16, 1951-1959 p.
Keyword [en]
Surface forces, polyelectrolyte-surfactant association, adsorption, turbidity, electrophoretic mobility
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-27218OAI: oai:DiVA.org:ri-27218DiVA: diva2:1054222
Note
A1289Available from: 2016-12-08 Created: 2016-12-08Bibliographically approved

Open Access in DiVA

No full text

By organisation
YKI – Ytkemiska institutet
In the same journal
Langmuir
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

Total: 4 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
v. 2.27.0