Analysis of the micellar properties of surfactants dodecyl trimethylammonium bromide and dodecyl trimethylammonium chloride in aqueous ionic liquids solution

Abstract

Understanding the influence of various additives on the properties of aqueous surfactant solutions is profoundly significant because of numerous applications of surfactant-based frameworks. Thus, the aggregation behavior of conventional cationic surfactants dodecyl trimethylammonium bromide (DTAB) and dodecyl trimethylammonium chloride (DTAC) has been investigated in the absence and presence of (0.05, 0.10, and 0.15) wt.% ionic liquids (ILs) 1-propyl-3-methylimidazolium bromide [C₃mim][Br] and 1-butyl-3-methylimidazolium bromide [C₄mim][Br] in aqueous medium at different temperatures (298.15, 303.15, and 308.15) K. The values of critical micelle concentration (CMC) have been evaluated for various IL/surfactant systems by employing three different techniques such as conductivity, fluorescence, and UV–VIS spectroscopy. The thermodynamic parameters of micellization have been ascertained utilizing these CMC values, determined by various techniques. Thermodynamic parameters like standard free energy, standard enthalpy, and standard entropy of micellization were examined in terms of driving force behind the process of micellization. These parameters revealed that the addition of ILs modifies the aggregation properties of DTAB and DTAC.

Graphical Abstract

Keywords:

• Surfactants
• ionic liquids
• micellization
• fluorescence
• CMC

Acknowledgments

The authors are also thankful to DST, New Delhi for DST-FIST [CSI-228/2011] Program, and The Director and Head, Department of Chemistry for providing necessary facilities.

Additional information

Funding

Authors (H.K.) are thankful to Science and Engineering Research Board (SERB), New Delhi for providing financial assistance to carry out research work vide sanction order number EMR/2015/002059. Arjuna Katal is thankful to the Department of Science and Technology (DST), New Delhi for providing DST INSPIRE Fellowship (IF150481). The sanction issues under the powers delegated to the Ministries and with the concurrence of the Integrated Finance Division, Department of Science & Technology vide their Dy.No. C/5872/IFD/2019-20 dated 2/27/2020 (MM/DD/YYYY) with the E File No: E 24593.