du.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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
Electrochemical properties of an amphiphilic viologen in differently charged micelles
Fysikalisk-kemiska institutionen, Uppsala universitet.ORCID iD: 0000-0002-3140-7378
Uppsala universitet.
Uppsala universitet.
Uppsala universitet.
2002 (English)In: Journal of Electroanalytical Chemistry, ISSN 0022-0728, E-ISSN 1873-2569, Vol. 536, no 1-2, p. 97-107Article in journal (Refereed) Published
Abstract [en]

The electrochemical properties of N-tetradecyl-N′-methylviologen (TMV) in differently charged micelles were studied with a glassy carbon electrode using electrochemical techniques. The redox potential varied depending on the charge of the surrounding surfactants. When the viologen was situated in cationic micelles the redox potential for the 2+/1+ reaction was more positive than when situated in negatively charged micelles. The non-ionic micelles destabilised the 2+-state most showing the highest redox potentials. From studies of several different cationic micelles it was concluded that the most important parameter for the redox potential was the surface charge density. A calculation based on a simple model confirmed this. Other interactions also influenced the stability of the redox states. Adsorption, desorption and reorganisation of the surfactants at the electrode surface caused capacitive currents. To control the nonfaradaic current, differential pulse voltammetry (DPV) was used in addition to cyclic voltammetry.

Place, publisher, year, edition, pages
Elsevier, 2002. Vol. 536, no 1-2, p. 97-107
Keywords [en]
DPV, micelle, electrochemistry, redox potential, amphiphilic viologen
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:du-16205DOI: 10.1016/S0022-0728(02)01208-1OAI: oai:DiVA.org:du-16205DiVA, id: diva2:756115
Available from: 2014-10-16 Created: 2014-10-16 Last updated: 2020-01-02Bibliographically approved
In thesis
1. Electrochemical Studies of Redox Properties and Diffusion in Self-Assembled Systems
Open this publication in new window or tab >>Electrochemical Studies of Redox Properties and Diffusion in Self-Assembled Systems
2004 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In this thesis electron transfer reactions and diffusion of redox molecules in three different types of self-aggregated structures are investigated. Electrochemistry was used to investigate the redox potential and diffusion coefficients for redox active molecules with different polarity. The first aggregate system studied was the micellar phase. The role of electrostatic interactions in the stability of an amphiphilic viologen was investigated for differently charged micelles. It was concluded that the electrostatic environment changed the redox potential of the viologen. In differently charged micelles the redox potential was more negative compared to when the viologen was situated in micelles with the same charge.

The second structure investigated is a very fascinating phase, the bicontinuous cubic phase, with its continuous channels of water and an apolar bilayer. Its domains with different polarity made it possible to solvate both hydrophilic and hydrophobic molecules. An amphiphilic molecule will have its head-group at the interface between the apolar and polar part, and can move lateral within the bilayer. All molecules investigated made contact with and reacted at the surface of the electrode. The diffusion of water bound species diffusing in the water channels was 3-4 times slower than in water. Hydrophobic and amphiphilic molecules were much more hindered, probably because the cubic phase was not defect free.

The third kind of structure studied was a lamellar system. This phase is built up from planar bilayers that are stacked with a repeating distance and with water in between. A hydrophilic molecule was severely hindered to move in the direction perpendicular to the bilayer plane. Upon addition of the peptide melittin the current increased, due to pore formation in the bilayer.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2004. p. 69
Keywords
Physical chemistry, electrochemistry, self-assembly, bicontinuos cubic phase, redox potential, diffusion, Fysikalisk kemi
National Category
Physical Chemistry
Identifiers
urn:nbn:se:du-31581 (URN)91-554-6059-3 (ISBN)
Public defence
2004-10-29, B22, BMC, Husargatan 3, 10:15
Opponent
Supervisors
Available from: 2020-01-02 Created: 2020-01-02 Last updated: 2020-01-02Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records BETA

Kostela, Johan

Search in DiVA

By author/editor
Kostela, Johan
In the same journal
Journal of Electroanalytical Chemistry
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 80 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • chicago-author-date
  • chicago-note-bibliography
  • 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