| KLÍČOVÁ, Ľubica, Peter ŠEBEJ, Peter ŠTACKO, Sergey K. FILLIPOV, Anna BOGOMOLOVA, Marc PADILLA BARRIENTO and Petr KLÁN. CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model? Langmuir. AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2012, vol. 28, No 43, p. 15185-15192. ISSN 0743-7463. Available from: https://dx.doi.org/10.1021/la303245e. |
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@article{1081189,
author = {Klíčová, Ľubica and Šebej, Peter and Štacko, Peter and Fillipov, Sergey K. and Bogomolova, Anna and Padilla Barriento, Marc and Klán, Petr},
article_number = {43},
doi = {http://dx.doi.org/10.1021/la303245e},
keywords = {Reverse micelles; CTAB; NMR; ITC},
language = {eng},
issn = {0743-7463},
journal = {Langmuir},
title = {CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model?},
url = {http://pubs.acs.org/doi/abs/10.1021/la303245e},
volume = {28},
year = {2012}
}
TY - JOUR
ID - 1081189
AU - Klíčová, Ľubica - Šebej, Peter - Štacko, Peter - Fillipov, Sergey K. - Bogomolova, Anna - Padilla Barriento, Marc - Klán, Petr
PY - 2012
TI - CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model?
JF - Langmuir
VL - 28
IS - 43
SP - 15185-15192
EP - 15185-15192
PB - AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN - 07437463
KW - Reverse micelles
KW - CTAB
KW - NMR
KW - ITC
UR - http://pubs.acs.org/doi/abs/10.1021/la303245e
N2 - The micellization of cetyltrimethylammonium bromide (CTAB) in chloroform in the presence of water was examined. Three scenarios of the reverse micelle formation, the closed, open and Eicke’s association models, were considered in the interpretation of the experimental data. The growth of the aggregates was observed through the changes of NMR signals of associated water, probing the microenvironment of the premicellar aggregates and the interior of reverse micelles. This technique if combined with isothermal titration calorimetry (ITC) revealed that hydrated surfactant premicellar aggregates are already present at 6 mM CTAB. NMR, ITC and conductometry were used to determine the critical micelle concentration (cmc) to be 40 mM CTAB. It is suggested that the variation of the cmc values reflects the fact that the NMR analysis indicated the beginning of the reverse micelle formation, whereas conductometry and ITC measurements provided the upper limit and an average value of a so-called apparent cmc, respectively. The cmc values were found to be unaffected by the water content. The presence of reverse micelles, the existence of multiple equilibria, and high polydispersity of the samples were evidenced by DOSY NMR spectroscopy. As a result, we validated Eicke’s association model, according to which cyclic inverse micelles are formed by a structural reorganization of linear associates within a narrow concentration range, called the apparent cmc. New experimental results have also been gained for micellization of cetyltrimethylammonium chloride (CTAC) in chloroform in the presence of water; a similar mechanism of reverse micelle formation has been suggested.
ER -
KLÍČOVÁ, Ľubica, Peter ŠEBEJ, Peter ŠTACKO, Sergey K. FILLIPOV, Anna BOGOMOLOVA, Marc PADILLA BARRIENTO and Petr KLÁN. CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model? \textit{Langmuir}. AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2012, vol.~28, No~43, p.~15185-15192. ISSN~0743-7463. Available from: https://dx.doi.org/10.1021/la303245e.
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