Closo-dodecaborate-based dianionic surfactants with distorted classical morphology: Synthesis and atypical micellization in water.

Autor: Hleli B; Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 40 Prague 2, Czech Republic., Medoš Ž; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia., Ogrin P; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia., Tošner Z; NMR Laboratory, Faculty of Science, Charles University, Hlavova 2030/8, 128 40 Prague 2, Czech Republic., Kereïche S; Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, 128 000 Prague 2, Czech Republic., Gradzielski M; Stranski-Laboratorium für Physikalische Chemie und Theoretische Chemie, Institut für Chemie Sekr. TC 7, Technische Universität Berlin, Strasse des 17. Juni 124, D-10623 Berlin, Germany., Urbič T; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia., Bešter-Rogač M; Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia. Electronic address: marija.bester@fkkt.uni-lj.si., Matějíček P; Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 40 Prague 2, Czech Republic. Electronic address: pavel.matejicek@natur.cuni.cz.
Jazyk: angličtina
Zdroj: Journal of colloid and interface science [J Colloid Interface Sci] 2023 Oct 15; Vol. 648, pp. 809-819. Date of Electronic Publication: 2023 Jun 10.
DOI: 10.1016/j.jcis.2023.06.013
Abstrakt: Hypothesis: To challenge the classical concept of step-like micellization of ionic surfactants with singular critical micelle concentration, novel amphiphilic compounds with bulky dianionic head and the alkoxy tail connected via short linker, which can complex sodium cations, were synthesized in the form of disodium salts.
Experiment: The surfactants were synthesized by opening of a dioxanate ring attached to closo-dodecaborate by activated alcohol, which allows for attachment of alkyloxy tails of desired length to boron cluster dianion. The synthesis of the compounds with high cationic purity (sodium salt) is described. Self-assembly of the surfactant compound at air/water interface and in bulk water was studied by tensiometry, light and small angle X-ray scattering, electron microscopy, NMR spectroscopy, MD simulations and by isothermal titration calorimetry, ITC. The peculiarities in the micelle structure and formation were revealed by thermodynamic modelling and MD simulations of the micellization process.
Findings: In an atypical process, the surfactants self-assemble in water to form relatively small micelles, where the aggregation number is decreasing with the surfactant concentration. The extensive counterion binding is a key characteristic of the micelles. The analysis strongly indicates complex compensation between the degree of bound sodium ions and the aggregation number. For the first time, a three-step thermodynamic model was used to estimate the thermodynamic parameters associated with micellization process. Diverse micelles differing in size and counterion binding can (co-)exist in the solution over the broad concentration and temperature range. Thus, the concept of step-like micellization was found inappropriate for these types of micelles.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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