scholarly journals Study of Micellar Behavior of Crown Ether and Tetraethylammonium Bromide in Aqueous Media

2010 ◽  
Vol 7 (2) ◽  
pp. 578-582 ◽  
Author(s):  
R. D. Singh ◽  
Rajni Garg
Keyword(s):  
Free Energy ◽  
Crown Ether ◽  
Surfactant Concentration ◽  
Aqueous Media ◽  
Critical Micellization Concentration ◽  
Conductivity Measurements ◽  
Tetraethylammonium Bromide ◽  
Micellization Process ◽  
Degree Of Counterion Dissociation ◽  
Separation Model

Conductivity measurements have been carried out to study the micellar behavior of tetraethylammonium bromide in presence of 15-crown-5 in aqueous media. The measurements were carried out at 298.15 K as a function of surfactant concentration with varying concentrations of crown ether. The influence of this association on the micellar parameters, such as the cmc (critical micellization concentration) and β (degree of counterion dissociation) have been analyzed. Thermodynamics of the systems were discussed in terms of the change in free energy of micellisation, ΔG0mby applying the charged pseudo-phase separation model. The trend shows that the micellization becomes less spontaneous in presence of crown ether. The influence of the presence of the inclusion complex on the micellization process of the surfactant has been studied.

scholarly journals Micellisation behavior on the dodecyltrimethylammonium bromide in the presence of Brij-35 in pure water by conductivity measurement

BIBECHANA ◽  
2017 ◽  
Vol 15 ◽  
pp. 85-89
Author(s):  
Neelam Shahi ◽  
Ajaya Bhattarai
Keyword(s):  
Free Energy ◽  
Sharp Increase ◽  
Pure Water ◽  
Specific Conductivity ◽  
Aqueous Media ◽  
Conductivity Measurement ◽  
Ammonium Bromide ◽  
Dodecyltrimethylammonium Bromide ◽  
Brij 35 ◽  
Versus Concentration

Conductivity measurement of dodecyltrimethylammonium bromide in the presence of Brij-35 in aqueous media at 289.15 K is performed. The result showed a sharp increase in conductivity with increase in the concentration of dodecyltrimethylammonium bromide in the presence of Brij-35. The graph of specific conductivity versus concentration is used in determining the critical micelle concentration (CMC). There is the decrease in CMC of  dodecyltrimethylammonium bromide in the presence of  Brij-35 in comparison with the CMC of  dodecyltrimethyl ammonium bromide [DTAB]. Gibbs free energy of micellisation has also been evaluated.   BIBECHANA 15 (2018) 85-89

On the Interaction of Insoluble Alkyl Alcohol Monolayers with Aqueous Solutions of Ionic Surfactants

1980 ◽  
Vol 35 (12) ◽  
pp. 1395-1401
Author(s):  
H.-F. Eicke ◽  
M. K. Sharma
Keyword(s):  
Aqueous Solutions ◽  
Surfactant Concentration ◽  
Critical Concentration ◽  
Sodium Dodecyl ◽  
Ionic Surfactants ◽  
Conductivity Measurements ◽  
Surfactant Aggregates ◽  
Film Balance ◽  
Intermediate Surface ◽  
Alcohol Monolayers

Abstract The interaction between so-called alkyl alcohol (C5-C8) monolayers and aqueous solutions of ionic surfactants with different hydrophilic properties, i.e. calcium di-2-ethylhexyl sulfosuccinate and sodium dodecyl sulfate, has been studied with the help of a Langmuir-Adam film balance. A decrease or increase in surface pressure of the alkyl alcohol monolayers with the addition of surfactants is observed. The shift of the critical concentration (cmc) to increasing surfactant concentration occurs at intermediate surface pressures. This is interpreted as due to the formation of mixed alcohol-surfactant aggregates. The maximum of the cmc as a function of the pressure can be explained by a thermodynamic treatment assuming competition between a pressure dependent solubility of alcohol molecules and the formation of mixed alcohol surfactant complexes. The amount of alkyl alcohol required to react with the surfactant has been evaluated at different surface pressures, which shows values similar to those known from cosurfactant studies in the bulk phase. Critical micelle concentrations of the surfactants were verified by conductivity measurements.

Influence of Surfactant-based Microheterogeneous Fluids on Aggregation of Copper Phthalocyanine Tetrasulfonate

1999 ◽  
Vol 03 (03) ◽  
pp. 188-195 ◽  
Author(s):  
JOHN P. ZELINA ◽  
CHRISTOPHER K. NJUE ◽  
JAMES F. RUSLING ◽  
GEOFFREY N. KAMAU ◽  
MIRIAM MASILA ◽  
...  
Keyword(s):  
Cationic Surfactant ◽  
Cationic Surfactants ◽  
Copper Phthalocyanine ◽  
Linear Regression Analysis ◽  
Aqueous Media ◽  
Association Constants ◽  
Micellar Solutions ◽  
Tetraethylammonium Bromide ◽  
Concentration Data ◽  
Bilayer Films

Electronic absorption spectroscopy was used to measure the molecular association of copper phthalocyanine tetrasulfonate in micellar solutions, a microemulsion made with cationic surfactant, and homogeneous solvents. Analysis of absorbance versus concentration data using a multiple-aggregation model and non-linear regression analysis gave values of association constants, molar absorptivities and estimates of average aggregation number. Microemulsions and aqueous micellar solutions made with alkylammonium surfactants inhibited aggregation, probably because of interactions between the phthalocyanine sulfonate groups and the cationic surfactant head groups at interfacial surfaces. Similar aggregation behavior was observed previously in multiple-bilayer films of cationic surfactants. Water and aqueous solutions containing tetraethylammonium bromide or anionic SDS micelles provide environments facilitating extensive aggregation of Cu II PcTS 4−. The major species are dimers in water and acetonitrile/water, but the formation of higher aggregates is promoted by addition of SDS or TEAB. Aprotic organic solvents provide environments intermediate between these two extremes, giving relatively large aggregation numbers (i.e. five to seven) but smaller association constants than aqueous media not containing cationic surfactants.

scholarly journals A Study of Local Anaesthetics. Part 202. Determination of the Critical Micellar Concentration of Carbisocainium Chloride in Water Using Spectral Methods and the Probe Pyrene

2013 ◽  
Vol 60 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. Gališinová ◽  
F. Andriamainty ◽  
I. Malík ◽  
J. Čižmárik ◽  
J. Karlovská ◽  
...  
Keyword(s):  
Spectral Methods ◽  
Emission Spectroscopy ◽  
Surfactant Concentration ◽  
Fluorescence Emission ◽  
Local Anaesthetics ◽  
Critical Micellar Concentration ◽  
Ratio Data ◽  
Micellization Process ◽  
Second Procedure

The micellization process of the local anaesthetic carbisocainium chloride in water was investigated by two spectral methods using the probe pyrene. First, the absorption spectroscopy in UV/VIS region was based on studying changes in characteristic absorption spectrum of pyrene in presence of surfactant. The resultant plot of the sum of absorbances for all the major pyrene peaks as a function of the total surfactant concentration shows, around the critical micellar concentration, a typical sigmoidal increase. The fluorescence emission spectroscopy in UV/VIS region of spectrum by the probe pyrene, second procedure, was applied for determination of the cmc from the measurements of the pyrene I1 /I3 ratio as a function of the surfactant concentration. The pyrene ratio data were fitted by the Boltzmann-type sigmoid of decreasing character.

Micellar catalysis of organic reactions. 22. A comparison of the basic hydrolysis of benzodiazepinones in the presence of reactive counterion micelles and vesicles

1988 ◽  
Vol 66 (7) ◽  
pp. 1566-1570 ◽  
Author(s):  
Trevor J. Broxton ◽  
Xenia Sango ◽  
Sallyanne Wright
Keyword(s):  
Surfactant Concentration ◽  
Biological Membranes ◽  
Micellar Catalysis ◽  
Organic Reactions ◽  
Conductivity Measurements ◽  
Amide Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Basic Hydrolysis ◽  
Hydrolysis Of ◽  
Good Agreement

The basic hydrolysis of diazepam and several N-alkyl nitrazepam derivatives has been studied in the presence of reactive counterion micelles of cetyltrimethylammonium hydroxide (CTAOH) and vesicles of didodecyldimethylammonium hydroxide (DDAOH). In both surfactants, the rate of hydrolysis of all compounds was found to be dependent on the hydroxide concentration at constant surfactant concentration and this was interpreted as evidence for initial amide hydrolysis. The hydrolysis in CTAOH was inhibited by added salts in the order Br− < NO3− < SO42−. At concentrations above 3 mM surfactant, the rate of hydrolysis of each compound was similar in CTAOH and in DDAOH. At lower concentrations of CTAOH, however, the rate of hydrolysis was significantly lower than that in DDAOH. On the basis of this evidence, it was concluded that the cmc of CTAOH was between 2–3 mM, which is in good agreement with the value of 1.8 mM obtained by Zana from conductivity measurements. For diazepam, a mechanistic change is indicated on transfer from water to either micelles or vesicles and since vesicles are considered good models of biological membranes, this suggests that conclusions concerning the bioavailability of diazepam should not be based on studies in water but rather on studies in either micelles or vesicles.

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