Total Description of Intrinsic Amphiphile Aggregation : Calorimetry Study and Molecular Probing
(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.
(Less)
- author
- Fernandez-Alvarez, Roberto ; Medoš, Žiga ; Tošner, Zdeněk ; Zhigunov, Alexander ; Uchman, Mariusz ; Hervø-Hansen, Stefan LU ; Lund, Mikael LU ; Bešter-Rogač, Marija and Matějíček, Pavel
- organization
- publishing date
- 2018
- 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}}, }