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
Bending elasticity of nonionic surfactant layers
YKI – Ytkemiska institutet. KTH Royal Institute of Technology, Sweden.
2009 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 25, no 4, 1949-1960 p.Article in journal (Refereed)
Abstract [en]

A novel approach to evaluate the bending elasticity of monolayers formed by nonionic surfactants with a rigid head group is introduced by means of considering head group repulsion as derived from the free energy of mixing rigid hydrophilic head groups with surrounding solvent molecules as well as contributions related to the hydrophobic tails. Explicit expressions for the spontaneous curvature (H0), bending rigidity (kc) and saddle-splay constant (k̄c) have been derived for the constraint of constant chemical potential of free surfactant (thermodynamically open layers) as well as the constraint of constant aggregation number (thermodynamically closed layers). Most interestingly, it is demonstrated that kc for thermodynamically open layers formed by a nonionic surfactant with rigid tail and head group always must be zero. However, kc for surfactants with a flexible tail as a function of the head group-to-tail volume ratio is found to go through a maximum at some large, positive value of k c and H0 ≈ 0. Eventually, kc falls below zero as the head group volume increases above a certain value. Hence, we may conclude that nonionic surfactants with a rigid head group may form thermodynamically stable fluid layers or aggregates only insofar the hydrophobic part is flexible with respect to chain conformational degrees of freedom and the head group is not too voluminous. It is found that the head group repulsion contribution to kcH0 is always positive whereas the corresponding contribution to k̄c may be positive or negative depending on whether the hydrophobic layer of the film is thicker or thinner than the hydrophilic layer.

Place, publisher, year, edition, pages
2009. Vol. 25, no 4, 1949-1960 p.
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-27117DOI: 10.1021/la802532nOAI: oai:DiVA.org:ri-27117DiVA: diva2:1054121
Note
A1985Available from: 2016-12-08 Created: 2016-12-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
YKI – Ytkemiska institutet
In the same journal
Langmuir
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

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