20.500.12556/RUL-147049 Closo-dodecaborate-based dianionic surfactants with distorted classical morphology synthesis and atypical micellization in water 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. dodecaborate surfactants self-assembly micelles calorimetry simulations dodekaborat surfaktanti samourejanje micele kalorimetrija simulacije true false true Angleški jezik Slovenski jezik Članek v reviji 2023-06-22 07:56:47 2023-06-22 07:56:48 2024-02-06 09:46:39 0000-00-00 00:00:00 2023 0 0 Str. 809-819 Vol. 648 15 Oct. 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.27 0021-9797 10.1016/j.jcis.2023.06.013 156408323 1-s2.0-S0021979723010330-main.pdf 1-s2.0-S0021979723010330-main.pdf 1 667FAF9559B544A945C6804D14379181 4508461ad4fbff51a681916f818028d7deca7ffe05eceaa4101ce52ba920dca0 3595cbdd-10c2-11ee-a314-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=170398 https://www.sciencedirect.com/science/article/pii/S0021979723010330 1 34368a54-10c1-11ee-a314-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=170397 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0