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Total Description of Intrinsic Amphiphile Aggregation : Calorimetry Study and Molecular Probing

Fernandez-Alvarez, Roberto ; Medoš, Žiga ; Tošner, Zdeněk ; Zhigunov, Alexander ; Uchman, Mariusz ; Hervø-Hansen, Stefan LU ; Lund, Mikael LU orcid ; Bešter-Rogač, Marija and Matějíček, Pavel (2018) In Langmuir 34(47). p.14448-14457
Abstract

Isothermal titration calorimetry (ITC) is an apt tool for a total thermodynamic description of self-assembly of atypical amphiphiles such as anionic boron cluster compounds (COSAN) in water. Global fitting of ITC enthalpograms reveals remarkable features that differentiate COSAN from classical amphiphiles: (i) strong enthalpy and weak entropy contribution to the free energy of aggregation, (ii) low degree of counterion binding, and (iii) very low aggregation number, leading to deviations from the ideal closed association model. The counterion condensation obtained from the thermodynamic model was compared with the results of 7Li DOSY NMR of Li[COSAN] micelles, which allows direct tracking of Li cations. The basic thermodynamic study of... (More)

Isothermal titration calorimetry (ITC) is an apt tool for a total thermodynamic description of self-assembly of atypical amphiphiles such as anionic boron cluster compounds (COSAN) in water. Global fitting of ITC enthalpograms reveals remarkable features that differentiate COSAN from classical amphiphiles: (i) strong enthalpy and weak entropy contribution to the free energy of aggregation, (ii) low degree of counterion binding, and (iii) very low aggregation number, leading to deviations from the ideal closed association model. The counterion condensation obtained from the thermodynamic model was compared with the results of 7Li DOSY NMR of Li[COSAN] micelles, which allows direct tracking of Li cations. The basic thermodynamic study of COSAN alkaline salt aggregation was complemented by NMR and ITC experiments in dilute Li/NaCl and acetonitrile aqueous solutions of COSAN. The strong affinity of acetonitrile molecules to COSAN clusters was microscopically investigated by all-atomic molecular dynamics simulations. The impact of ionic strength on COSAN self-assembling was comparable to the behavior of classical amphiphiles, whereas even a small amount of acetonitrile cosolvent has a pronounced nonclassical character of COSAN aggregation. It demonstrates that large self-assembling changes are triggered by traces of organic solvents.

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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
34
issue
47
pages
14448 - 14457
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:30343575
  • scopus:85056887024
ISSN
0743-7463
DOI
10.1021/acs.langmuir.8b03462
language
English
LU publication?
yes
id
289057ac-1d8d-414a-be16-e7fa74b4dba1
date added to LUP
2018-11-30 08:58:36
date last changed
2024-04-01 16:37:14
@article{289057ac-1d8d-414a-be16-e7fa74b4dba1,
  abstract     = {{<p>Isothermal titration calorimetry (ITC) is an apt tool for a total thermodynamic description of self-assembly of atypical amphiphiles such as anionic boron cluster compounds (COSAN) in water. Global fitting of ITC enthalpograms reveals remarkable features that differentiate COSAN from classical amphiphiles: (i) strong enthalpy and weak entropy contribution to the free energy of aggregation, (ii) low degree of counterion binding, and (iii) very low aggregation number, leading to deviations from the ideal closed association model. The counterion condensation obtained from the thermodynamic model was compared with the results of 7Li DOSY NMR of Li[COSAN] micelles, which allows direct tracking of Li cations. The basic thermodynamic study of COSAN alkaline salt aggregation was complemented by NMR and ITC experiments in dilute Li/NaCl and acetonitrile aqueous solutions of COSAN. The strong affinity of acetonitrile molecules to COSAN clusters was microscopically investigated by all-atomic molecular dynamics simulations. The impact of ionic strength on COSAN self-assembling was comparable to the behavior of classical amphiphiles, whereas even a small amount of acetonitrile cosolvent has a pronounced nonclassical character of COSAN aggregation. It demonstrates that large self-assembling changes are triggered by traces of organic solvents.</p>}},
  author       = {{Fernandez-Alvarez, Roberto and Medoš, Žiga and Tošner, Zdeněk and Zhigunov, Alexander and Uchman, Mariusz and Hervø-Hansen, Stefan and Lund, Mikael and Bešter-Rogač, Marija and Matějíček, Pavel}},
  issn         = {{0743-7463}},
  language     = {{eng}},
  number       = {{47}},
  pages        = {{14448--14457}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Langmuir}},
  title        = {{Total Description of Intrinsic Amphiphile Aggregation : Calorimetry Study and Molecular Probing}},
  url          = {{http://dx.doi.org/10.1021/acs.langmuir.8b03462}},
  doi          = {{10.1021/acs.langmuir.8b03462}},
  volume       = {{34}},
  year         = {{2018}},
}