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Total description of intrinsic amphiphile aggregation: calorimetry study and molecular probing
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SYSNO ASEP 0497397 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Total description of intrinsic amphiphile aggregation: calorimetry study and molecular probing Author(s) Fernandez-Alvarez, R. (CZ)
Medoš, Ž. (SI)
Tošner, Z. (CZ)
Zhigunov, Alexander (UMCH-V) RID, ORCID
Uchman, M. (CZ)
Hervo-Hansen, S. (SE)
Lund, M. (SE)
Bešter-Rogač, M. (SI)
Matějíček, P. (CZ)Source Title Langmuir. - : American Chemical Society - ISSN 0743-7463
Roč. 34, č. 47 (2018), s. 14448-14457Number of pages 10 s. Language eng - English Country US - United States Keywords ITC ; NMR ; SAXS Subject RIV CD - Macromolecular Chemistry OECD category Polymer science Institutional support UMCH-V - RVO:61389013 UT WOS 000451789300037 EID SCOPUS 85056887024 DOI 10.1021/acs.langmuir.8b03462 Annotation 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. Workplace Institute of Macromolecular Chemistry Contact Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Year of Publishing 2019
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