CTAB/Water/Chloroform Reverse Micelles: A Closed or Open
Association Model?

J 2012

CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model?

KLÍČOVÁ, Ľubica; Peter ŠEBEJ; Peter ŠTACKO; Sergey K. FILLIPOV; Anna BOGOMOLOVA et al.

Základní údaje

Originální název

CTAB/Water/Chloroform Reverse Micelles: A Closed or Open Association Model?

Autoři

KLÍČOVÁ, Ľubica; Peter ŠEBEJ; Peter ŠTACKO; Sergey K. FILLIPOV; Anna BOGOMOLOVA; Marc PADILLA BARRIENTO a Petr KLÁN

Vydání

Langmuir, AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2012, 0743-7463

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10401 Organic chemistry

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 4.187

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/12:00058054

Organizační jednotka

Přírodovědecká fakulta

DOI

https://doi.org/10.1021/la303245e

UT WoS

000310484300009

Klíčová slova anglicky

Reverse micelles; CTAB; NMR; ITC

Štítky

AKR, rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 1. 4. 2015 22:17, prof. RNDr. Petr Klán, Ph.D.

Anotace

V originále

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.

Návaznosti

ED0001/01/01, projekt VaV

Název: CETOCOEN

GAP503/10/0947, projekt VaV

Název: Důsledky fotochemické aktivity organických polutantů v polárních oblastech

Investor: Grantová agentura ČR, Důsledky fotochemické aktivity organických polutantů v polárních oblastech

Citovat

KLÍČOVÁ, Ľubica; Peter ŠEBEJ; Peter ŠTACKO; Sergey K. FILLIPOV; Anna BOGOMOLOVA; Marc PADILLA BARRIENTO a 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, roč. 28, č. 43, s. 15185-15192. ISSN 0743-7463. Dostupné z: https://doi.org/10.1021/la303245e.

@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 = {https://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 a 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, roč.~28, č.~43, s.~15185-15192. ISSN~0743-7463. Dostupné z: https://doi.org/10.1021/la303245e.

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