Experimental Study of CMC Evaluation in Single and Mixed Surfactant Systems, Using the UV–Vis Spectroscopic Method

Kaur

2017

The self-aggregation of sodium dodecylsulphate (SDS), an anionic surfactant, in aqueous solutions of tetraalkylammonium bromide salts (R 4 NBr, where R = propyl, butyl and pentyl) was determined at various temperatures in the range 288.15-318.15 K. The critical micelle concentration (CMC) determined from conductivity data was used to study the thermodynamics of the surfactant. The presence of bromide salts was found to affect the micellization of SDS in accordance with the hydrophobicity of the tetraalkylammonium cations, thus the CMC values follow the order no additive [ Pr 4-NBr [ Bu 4 NBr [ Pen 4 NBr. The results from conventional conductivity methods were combined with those of spectroscopic techniques like fluorescence and UV-Vis studies.

Section: Spectroscopic Measurementsmentioning

confidence: 99%

Modulation of Aggregation Behaviour of Anionic Surfactant in the Presence of Aqueous Quaternary Ammonium Salts

Kaur

2017

“…The fluorescence emission spectrum of pyrene exhibits five characteristic bands in the region 370-400 nm. The polarity of the microenvironment around the pyrene molecules is related to the ratio of the intensities of the first to third major vibrational peaks (I 1 /I 3 ) and lower value of I 1 /I 3 indicates apolar environment [50,51]. Pyrene molecules get distributed into micelles as soon as they form and this process is accompanied by an abrupt decrease in the I 1 /I 3 ratio indicating the micellization process, when a surfactant is added to an aqueous solution containing pyrene.…”

Section: Fluorescence Probe Studiesmentioning

confidence: 99%

“…The absorption spectrum of pyrene has evidenced eight strong (s) and weak (w) peaks (232 w, 242 s, 252 w, 260 w, 272 s, 308 w, 320 s, and 336 s nm). It is reported that the absorbance at 242 nm increases with the polarity of the solvent, while above 315 nm, absorbance decreases with the solvent polarity [51,52]. Since there is no hydrophilic functionality of pyrene, the absorbance of the pyrene peaks enhances with increase in concentration of surfactants.…”

Section: Uv-vis Probe Studiesmentioning

confidence: 99%

Physico‐chemical and Spectroscopic Approach to Analyse the Behaviour of Surface‐Active Ionic Liquid and Conventional Surfactant in Aqueous Glycine

Kumar

Kaur

et al. 2017

The present work reports a comparison of direct or indirect (water‐mediated) interactions of surface active ionic liquid SAIL, tetrabutylammonium dodecylsulphate (TBADS) in aqueous solutions of glycine with those of sodium dodecylsulphate (SDS) in same solvent system, by employing techniques like conductivity, fluorescence, UV–Vis probe studies and clouding phenomenon. High hydrophobicity and penetrating ability of TBA+ counterions and most significant salting‐out effect due to the preferential hydration of glycine molecules accounts for the enhanced micellization and better surface activity of TBADS as compared to its conventional analogue SDS. Further, driving force for the micellization in both the cases is the hydrophobic interactions, whereas in the case of SDS, London dispersion interactions as alternative forces also contribute considerably at higher temperatures. In addition, the decrease in the cloud point (Tcp) of aqueous TBADS solutions in the presence of glycine is attributed to the dehydration of hydrophilic head groups of micelles, resulting in their collapse and hence phase separation.

“…The small increase in the absorbance at low surfactant concentration (pre‐micellar region) suggests tendency of pyrene to stay in polar environment of water molecules and low solubilization of pyrene. However at CMC, the abrupt increase in the absorbance shows migration of hydrophobic pyrene into hydrophobic environment of micelles and its high solubility (Tanhaei et al, 2013). The higher A T values of drug‐surfactant system as compared to aqueous surfactant systems put ahead the supremacy of hydrophobic interactions in the former.…”

Section: Resultsmentioning

confidence: 99%

Aggregation and Adsorption Behavior of Cationic Surfactants (Cetyltrimethylammonium Bromide and Dodecyltrimethylammonium Bromide) in Aqueous Solutions of Antibiotic Drug (Amikacin Sulphate) at Different Temperatures

Chaudhary

Sharma³

2020

Conductivity and spectroscopy techniques have been accomplished to comprehend the mechanism of supramolecular assembly of cetyltrimethylammonium bromide (CTAB) and dodecyltrimethylammonium bromide (DTAB) in aqueous solution of amikacin sulphate (0.001, 0.005, and 0.010 mol kg −1). For CTAB, the normal boost of the CMC value with rise in temperature manifests the significant role of aquaphilic dehydration. However, the aquaphobic dehydrations become prominent with temperature and depict typical U-shaped behavior of CMC for DTAB. The thermodynamic parameters of micellization have been derived from CMC values. The outcomes have been conferred in terms of solvation of hydrophobic part of surfactants by hydrophobic part of amikacin sulphate and micellization becomes more favorable for surfactant with more hydrophobic character in the presence of drug. The alteration in micro-environment of the ternary (drug/surfactant/water) system has been explained in terms of fluorescence emission intensity of surfactant solutions which has been found to decrease by the addition of drug. The obtained absorbance spectrum by varying concentrations of surfactant/drug affords noteworthy information regarding the diverse interactions in studied systems. Moreover, the exhaustive understanding of surfactant micellar behavior have been discussed in consideration of use of surfactants as drug delivery agents and hence to amplify drug bioavailability consequently remodeling its treatment efficacy.