Entropy Of Micellization Research Articles

The Dynamic Impact of Synthetic Dyes on the Physicochemical Parameters of Cationic and Anionic Surfactants

Introduction: The interaction of dyes (crystal violet, malachite green, and congo red) with cationic (cetrimide) and anionic surfactants (sodium dodecyl sulfate) in the aqueous medium were studied via conductometric and UV-visible spectroscopy. Method: The critical micelle concentration (CMC) of both cetrimide and SDS upsurges in all the selected dyes on increasing the temperature. Thermodynamic parameters like change in Gibb’s free energy of micellization (Δ G°m ), change in enthalpy of micellization (Δ H°m ) as well as change in entropy of micellization (Δ S°m ) were calculated by employing mass action model. Result: The Δ S°m values obtained are positive with Δ G°m and Δ H°m values being negative signified that the phenomenon of micellization is spontaneous as well as exothermic in nature. Moreover, the more negative Δ H°m in water as well as in the presence of dyes signify the presence of electrostatic forces of attraction between the oppositively charged dyes and surfactant moieties. UV-spectroscopy reveals that spectral changes occur because of the interaction of surfactants with dye molecules. Conclusion: By analyzing shifts in absorption peaks, changes in intensity, and alterations in band shape, insights into the nature of surfactant-dye complexes and their potential applications in various industries can be assessed. This understanding can help in the design and optimization of products and processes involving surfactants and dyes.

Investigation of micellization and thermodynamic properties of cationic gemini surfactant (12-2-O-2-12) in the presence of organic solvents

The micellization behaviour and thermodynamic properties of synthesized cationic gemini surfactant (12-2-O-12-12), N,N′-didodecyl-N,N,N′,N′-tetramethyl-N,N′-(oxybis(ethane-2,1-diyl))-diammonium dibromide were studied in the presence of organic solvents for four different temperatures (25, 30, 35 and 40 °C). Aqueous solutions of 10 % and 20 % methanol (MeOH), ethanol (EtOH), isopropanol (IPOH) and dimethyl sulfoxide (DMSO) were used as solvents. The critical micelle concentration (CMC) of cationic gemini surfactant and the degree of counterion dissociation (α) were determined by the conductometric method. Using the CMC and α values for each of the four temperatures, the values of the standard Gibbs free energy (ΔGmo), Gibbs free energy of transfer (ΔGm,transo), enthalpy (ΔHmo), and entropy (ΔSmo) of micellization were calculated. It was observed that the CMC and α values increased with increasing solvent percentage and temperature. It was found that in all cases, the standard Gibbs free energy and enthalpy values were negative while both the micellization entropy and the standard Gibbs free energy of transfer are positive. Negative Gibbs free energy values indicated that micellization was a spontaneous situation, while positive entropy values indicated the existence of a disordered situation. The positive ΔGm,transo values show that the presence of solvents makes the environment unfavorable for micelle formation.

Physicochemical Properties of Cetrimonium Bromide in Electrolytes and Nonelectrolyte Environments

Background: The physicochemical properties, including the thermodynamics of micellization studies, received much attention. Cationic surfactant cetrimonium bromide (C16TABr) in electrolytes (sodium chloride and sodium salicylate) and nonelectrolyte (Ethylene glycol) in an aqueous solution were examined, and interesting results were obtained. The present investigation aims to identify a suitable combination of cationic surfactant cetrimonium bromide + electrolytes and nonelectrolytes having the ability to alter the size or shape of the micellar system using available methods. Methods: Surface tension, conductivity, viscosity, ultrasonic velocity, and dynamic light scattering (DLS) methods at different temperatures (303-323K) were used during the experimental research work. Results: The experimental results pointed out that the incorporation of electrolytes and nonelectrolyte into the cationic surfactant affects the physicochemical properties such as critical micelle concentration (CMC), surface tension (ST), degree of ionization (α), degree of counterion binding (β), standard Gibbs free energy of micellization (ΔGo m), standard entropy of micellization (ΔSo m), standard heat of micellization (ΔHo m), viscosities, and acoustic parameters. Dynamic light scattering (DLS) measurements reveal exciting facts related to the size and shape transformation of the mixed micellar assembly. Structure modification can be obtained by choosing right the combination of cationic surfactant cetrimonium bromide + electrolytes (sodium chloride and sodium salicylate) and nonelectrolyte (Ethylene glycol) ratio. Conclusion: It concluded that, over a threshold level, an electrolyte such as NaCl concentration causes the micelle size to rise. The entropy of micellization goes down when a structure-breaker (EG) is added to the water phase, and this is because the structure of the water is changed near hydrophobic groups. The physicochemical features of cetrimonium bromide (C16TABr) show unique behaviour under the influence of micelle-driven and micelle- forbidden systems.

Exploration of Cloxacillin Sodium interaction with Aggregates of Benzimidazolium Gemini Surfactants: Spectroscopic and Biophysical Analysis

AbstractThe interaction of benzimidazolium gemini surfactants viz. 1,3‐bis‐(1‐octylbenzimidazolium) propane bromide, simply represented as BG8, and 1,3‐bis‐(1‐decylbenzimidazolium) propane bromide (BG10) with an antibiotic drug cloxacillin sodium (CLX) was explored by surface tension measurements. Numerous interfacial parameters viz. minimum surface area per molecule ( ), maximum surface excess concentration ( ), packing parameter (P) and thermodynamic parameters like Gibbs free energy of micellization ( ), enthalpy of micellization ( ) and entropy of micellization ( at different temperatures were observed. Steady‐state fluorescence has been done for comprehension of micro‐environment of the aggregates as well as to calculate the binding constants ( ) and Gibbs free energy change (ΔG). Dynamic light scattering results gave evidence regarding the size of aggregates of CLX‐BG complexes. Also, comparative studies by UV‐ visible, FTIR, 1HNMR, and viscometry have been done to further investigate the interaction of CLX with BG8/BG10 surfactants.

Thermodynamic Insights of the Molecular Interactions of Dopamine (Neurotransmitter) with Anionic Surfactant in Non-Aqueous Media.

This study was aimed at establishing the interactions prevailing in an anionic surfactant, sodium dodecyl sulfate, and dopamine hydrochloride in an alcoholic (ethanol) media by using volumetric, conductometric, and tensiometric techniques. Various methods were utilized to estimate the critical micelle concentration (cmc) values at different temperatures. The entire methods yielded the same cmc values. The corresponding thermodynamic parameters viz. the standard free energy of micellization (Gmico), enthalpy of micellization (Hmico), and entropy of micellization (Smico) were predicted by applying the pseudo-phase separation model. The experimental density data at different temperatures (298.15 K, 303.15 K, 308.15 K, and 313.15 K) were utilized to estimate the apparent molar volumes (Vϕo) at an infinite dilution, apparent molar volumes (Vφcmc) at the critical micelle concentration, and apparent molar volumes (ΔVφm) upon micellization. Various micellar and interfacial parameters, for example, the surface excess concentration (Γmax), standard Gibbs free energy of adsorption at the interface (ΔGoad), and the minimum surface area per molecule (Amin), were appraised using the surface tension data. The results were used to interpret the intermolecular interactions prevailing in the mixed systems under the specified experimental conditions.

Comparative Interaction of Flavonoid Quercetin with Different Tween Surfactants

For solubilizing the flavonoid Quercetin (Qct), many mediums are adopted. Surfactant solubilization is important among them. In this work, the interaction of Qct with three nonionic tween surfactants, viz., Tween 20, Tween 40, and Tween 80 was investigated. The effect of the length of the carbon chain on the interaction was analyzed by conductometry, infrared spectroscopy, UV–visible spectroscopy, and antioxidant studies. The experimental results suggested that Tween 80 was most efficient out of the three tween surfactants taken for the study. From the conductivity studies the counterion binding constant β was used to calculate various thermodynamic parameters like Gibbs free energy, ΔG0m, enthalpy, ΔH0m, and entropy of micellization, ΔS0m. The order of stability is given as Qct-Tween 80 > Qct-Tween 20 > Qct-Tween 40. The theoretical values also corroborate the same order of interaction with the three surfactants.

Linear hydrophobic congeneric groups of bile acid anion derivatives based on the self-association (micellization) process and the phenomenon of enthalpy–entropy compensation

If anions of bile acids form primary micelles by means of hydrophobic effect and interaction, then these anions of bile acids in the lnk - lnCMC plane (k = RP-HPLC capacity factor and CMC = Critical Micellization Concentration) form linear hydrophobic congeneric groups (LCG). Bile salts that form H-bonds in the primary micelles hydrophobic domain are outliers concerning LCG from the plane lnk - lnCMC. In the manuscript, LCG is described using a thermodynamic approach (analytical theory). LCG resulting from enthalpy-entropy compensation (EEC) in the plane of enthalpy and entropy of bile salts micellization is connected with an LCG in the plane of lnk - lnCMC. Bile acid anion, an outliner in the plane of lnk – lnCMC, in the plane of enthalpy and entropy of micellization is included in LCG. This means that in the EEC phenomenon, the formation of LCG is not determined solely by the hydrophobic effect and interaction but also by the energy and the entropy changes of the hydrogen bonds in primary micelles.

Chemico-Physical Properties of Some 1,1'-Bis-alkyl-2,2'-hexane-1,6-diyl-bispyridinium Chlorides Hydrogenated and Partially Fluorinated for Gene Delivery.

The development of very efficient and safe non-viral vectors, constituted mainly by cationic lipids bearing multiple charges, is a landmark for in vivo gene-based medicine. To understand the effect of the hydrophobic chain's length, we here report the synthesis, and the chemico-physical and biological characterization, of a new term of the homologous series of hydrogenated gemini bispyridinium surfactants, the 1,1'-bis-dodecyl-2,2'-hexane-1,6-diyl-bispyridinium chloride (GP12_6). Moreover, we have collected and compared the thermodynamic micellization parameters (cmc, changes in enthalpy, free energy, and entropy of micellization) obtained by isothermal titration calorimetry (ITC) experiments for hydrogenated surfactants GP12_6 and GP16_6, and for the partially fluorinated ones, FGPn (where n is the spacer length). The data obtained for GP12_6 by EMSA, MTT, transient transfection assays, and AFM imaging show that in this class of compounds, the gene delivery ability strictly depends on the spacer length but barely on the hydrophobic tail length. CD spectra have been shown to be a useful tool to verify the formation of lipoplexes due to the presence of a "tail" in the 288-320 nm region attributed to a chiroptical feature named ψ-phase. Ellipsometric measurements suggest that FGP6 and FGP8 (showing a very interesting gene delivery activity, when formulated with DOPE) act in a very similar way, and dissimilar from FGP4, exactly as in the case of transfection, and confirm the hypothesis suggested by previously obtained thermodynamic data about the requirement of a proper length of the spacer to allow the molecule to form a sort of molecular tong able to intercalate DNA.

Effect of hydrophilic atenolol and lipophilic propranolol β-blockers on the surface and bulk aggregation of quaternary ammonium bromide surfactants: A comparative study

The variations in the surface and bulk properties of alkyltrimethylammonium bromide (ATAB) surfactants (C12 to C16) in presence of a hydrophilic β-blocker drug atenolol (ATL) and a lipophilic β-blocker drug propranolol (PPL), have been investigated using three independent techniques, viz; electrical conductivity, surface tension and cyclic voltammetry. Electrical conductivity measurement indicates that both ATL and PPL at low concentrations of 0.5 mM and 1.0 mM brings about almost equal changes to the critical micelliastion concentration of all ATAB surfactants. However, at higher concentrations (3 mM to 10 mM), PPL seems to be more effective, than ATL, in reducing the cmc and hence favouring micellization. Various interfacial parameters at the air–water interface have been determined through the measurements of surface tension of the surfactants in varying concentrations of ATL and PPL ranging from 0.5 mM to 10 mM. The thermodynamic parameters of micellization are evaluated from the temperature dependence of cmc. The variation of Gibbs energy with temperature is small while large changes in enthalpy and entropy of micellization are observed in the temperature range studied. The effect of TTAB on the electrolytic solutions of ATL and PPL on the voltametric response of glassy carbon electrode (GCE) was examined. TTAB enhanced the current signal of ATL while opposite effect was observed for PPL. The experimental results have been analysed in terms of the difference in the hydrophobicities of the two β-blocker drug molecules.

Application of anionic-nonionic mixed micellar system for solubilization of methylene blue dye

Present study highlights the interaction of methylene blue (MB), a cationic dye, with anionic surfactant, sodium dodecyl sulfate (SDS), and its mixed micelles with a nonionic surfactant Triton X-114 (TX-114). The results obtained from UV–visible spectrophotometry were used to obtain the degree of solubilization in terms of binding constant (Kb) and partition coefficient (Kx) of dye in single and mixed micellar systems (MMS). Gibb’s free energies of partitioning and binding were also calculated for both systems. Specific conductance was measured to determine the CMC of single and mixed micellar media at five different temperatures, T = (293.15 – 333.15) K. Temperature-dependent thermodynamic parameters like Gibb’s free energy of micellization (ΔGomic), enthalpy of micellization (ΔHomic), and entropy of micellization (ΔSomic) were calculated using data of specific conductance measurements. Effect of concentration of TX-114 on Kx and Kb values of the MB in MMS is also investigated. Spectroscopic and conductometric results revealed that the anionic-nonionic mixed micellar system was better and more effective for the removal and solubilization of MB from aqueous system as compared to anionic micelles only. However, it has been observed that after a critical concentration an increase of non-ionic surfactant concentration has a reverse effect on solubilizing power of ionic-nonionic mixed micellar system. This indicates that the dye-surfactant interaction became weaker due to possible decrease in ionic character of mixed micelles when the high fraction of TX-114 was used.

Aggregation and adsorption behavior of cobalt‐based metallosurfactant in water–ethylene glycol media forming worm‐like micelles

AbstractThe cobalt based metallosurfactant cis‐chlorobis(ethylenediamine)hexadecylaminecobalt(III) chloride (CHCC) has been prepared and well characterized by utilizing elemental analysis, NMR (1H, 13C), FT‐IR and UV–Vis spectroscopy. The CHCC metallosurfactant shows thermal stability up to 168°C. The micellization behavior of the synthesized CHCC metallosurfactant has been investigated systematically by the tensiometric, conductometric, and fluorescence techniques. The critical micelle concentration (cmc) values of CHCC have been determined in various water–ethylene glycol mixtures ranging from 0 to 100 weight % of ethylene glycol at 293.15, 298.15, 303.15, and 308.15 K. The physicochemical parameters namely counterion binding constant, surface pressure, surface excess, surface area covered per CHCC metallosurfactant molecule, free energy minimum, standard free energies of micellization and adsorption, standard enthalpy and entropy of micellization, and Gibb's free energy of transfer have been calculated. The hydrodynamic diameters and zeta potentials of the CHCC metallomicelles have been measured by dynamic light scattering method. Transmission electron microscopy was employed to confirm the presence of worm‐like micelles.

An Insight Into the Effect of Drug Betaine Hydrochloride on the Micelle Forming Tendency of Surfactant AOT

The present analysis employs an electrical conductometric measurements to monitor the effect of addition of drug Betaine hydrochloride (BH) on the double chain anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Different concentrations (0.10, 0.25, and 0.50) mmolkg-1 of drug Betaine hydrochloride have been added to the aqueous solution of surfactant AOT at three various temperatures (298.15, 308.15, and 318.15)K in order to examine the micellization properties of the surfactant AOT. The values of critical micelle concentration, and various thermodynamic quantities, which include Gibb’s free energy of micellization (ΔG0 m), enthalpy of micellization (ΔH0 m), and entropy of micellization (ΔS0 m), have been computed from the conductivity measurements. The interactions prevailing among the surfactant-drug system have been discussed in order to explore their applications in drug delivery systems.

An Investigation on Drug Binding Ability of Cationic Surfactant CTAB

Taking in consideration the application of surfactants in drug delivery, the interactions of cationic surfactant cetyltrimethylammonium bromide (CTAB) with drug Betaine Hydrochloride have been scrutinized. The micellization behaviour of surfactant is investigated at three different temperatures (298.15, 308.15, and 318.15)K in presence of various concentrations (0.10, 0.25, and 0.50) mmolkg-1 of drug Betaine hydrochloride via conductivity measurements The critical micelle concentration (CMC) attained though conductometric measurements has been utilized to obtain different thermodynamic parameters of micellization i.e. standard free energy of micellization (ΔG0 m), standard enthalpy of micellization (ΔH0 m), and standard entropy of micellization (ΔS0 m).

Comparative Thermodynamic Studies of the Micellization of Amphiphilic Block Copolymers before and after Cyclization.

The enthalpy and entropy of micellization in water, ΔHmic and ΔSmic, respectively, of three linear amphiphilic BAB block copolymers consisting of either poly(methyl acrylate) (Mn ∼ 1200 and 700 Da) or poly(ethyl acrylate) (Mn ∼ 800 Da) as hydrophobic (B) segments and poly(ethylene oxide) (PEO) as the hydrophilic (A, Mn ∼ 3000 Da) segment were determined by isothermal titration calorimetry (ITC). The ΔHmic and ΔSmic of the cyclic AB block copolymers obtained by cyclization of the linear triblock copolymers were determined under the same conditions. The ΔHmic value of the cyclic copolymers was smaller than that of their linear precursors. The ΔSmic value showed the same trend, but the relative difference between the cyclized and linear copolymers was less pronounced. The hydrodynamic diameter (Dh), critical micelle concentration (CMC), molecular weight (Mw-mic), and second virial coefficient (A2) of the micelles were determined. The Dh value of the cyclic copolymer micelles was smaller than the linear counterpart. On the other hand, the CMC value became larger, whereas the A2 value was comparable or increased by cyclization. Overall, the results suggest that, in the unimer state, the hydrophobic segments of the cyclized copolymers form a tightly coiled structure to minimize contact with water, resulting in the smaller ΔHmic value. Contrary to the linear copolymer micelles, the cyclic copolymer micelles have no "dangling chains", which may explain the topology-driven slight difference in the ΔSmic value.

Interaction of cationic surfactant with acid yellow dye in absence/presence of organic and inorganic additives: conductivity and dye solubilization methods

Abstract In the present study, the conductometric and dye-solubilization techniques have been utilized to investigate the interaction between an anionic dye (acid yellow 23 [AY]) and a cationic surfactant (cetyltrimethylammonium bromide [CTAB]) in presence of organic (ethanol)/inorganic (NaCl) additives. From the conductometric method, two critical micelle concentrations (cmc) were found for AY + CTAB mixture in an aqueous system and the cmc values were found to undergo a change with the variation of AY concentrations. The cmc values of AY + CTAB systems were observed higher in the alcoholic medium, while the same was found to be lower in the NaCl solutions. The change in cmc of AY + CTAB systems shows an U-like curve with an increase of temperature. The negative free energy of micellization ( Δ G m o ${\Delta}{G}_{m}^{o}$ ) for the AY + CTAB systems has indicated a spontaneous micelle formation in all of the cases studied. The enthalpy ( Δ H m o ${\Delta}{H}_{m}^{o}$ ), as well as the entropy of micellization ( Δ S m o ${\Delta}{S}_{m}^{o}$ ) for the AY + CTAB systems, were assessed and discussed with proper reasoning. Additionally, the enthalpy-entropy compensation parameters were also investigated and illustrated. The solubility of AY and C D was observed to rise linearly with an increase in the concentration of CTAB/NaCl solution. The solubilization capacity (χ) of AY, the molar partition coefficient (K M) amongst the micellar and the aqueous phase, and free energy of solubilization ( Δ G S o ${\Delta}{G}_{S}^{o}$ ) were evaluated and discussed in detail. The former parameters undergo an increase with an increase of NaCl concentrations.

Interactions of tricyclic antidepressant drug chlomipramine hydrochloride with imidazolium based surface active ionic liquid in aqueous solution

Tricyclic antidepressant drug, Chlomipramine hydrochloride (CLP) with surface active ionic liquid (SAIL), 1-octyl-3-methylimidazolium chloride, was investigated using electrical conductivity. Various theoretical models were employed to calculate various interaction parameters and thermodynamic parameters. Different mole fractions of CLP with SAIL were studied to evaluate the critical micelle concentration (CMC) using electrical conductivity measurements. The change in Gibbs free energy of micellization, change in enthalpy of micellization, change in entropy of micellization, micellar mole fraction, χ1, of the CLP, and the interaction parameter, β, activity coefficients ƒ1 and ƒ2were calculated. The χIdeal and χ1 values were observed to increase on increasing the mole fraction of CLP from 0.4 to 0.6. This may be an indication of drug molecules being adsorbed on the micellar surface. As a result the mixed system (CLP and SAIL) were found to form stable mixed micelles.

Effect of caffeine on the micellization and related thermodynamic parameters of sodium dodecyl sulphate, hexadecyltrimethylammonium bromide and triton x-100: a physicochemical study

ABSTRACT Effect of caffeine on the micellization of anionic surfactant (SDS), cationic surfactant (HTAB) and non-ionic surfactant (Tx-100) was investigated using the conductometric and tensiometric techniques. The thermodynamic parameters such as change in Gibbs-free energy, , change in enthalpy of micellization, , change in entropy of micellization, , change in Gibbs-free energy of transfer, , surface excess concentration, , minimum area per surfactant molecule, , surface pressure, , change in Gibbs-free energy of adsorption, and other related parameters were calculated to gain insights into the interactions of caffeine with different surfactants at different temperatures. The CMC in mole fraction units, , values of SDS in caffeine are low, while that of HTAB are large in comparison with the values reported in water. The negative values of and and the positive values of are indicative of SDS-caffeine and HTAB-caffeine interactions.

Micellization Behaviour of Cationic Surfactants in the Presence of Food Additives: Conductance and Spectroscopic Investigations

Aim: The micellization behavior of cationic surfactants has been studied in the presence of food additives. Objectives: Micellization behaviour of cationic surfactants, Cetyltrimethylammonium Bromide (CTAB) and Tetradecyltrimethylammonium Bromide (TTAB) has been studied in water and in various concentrations of salts (food additives) L-glutamic acid, sodium propionate, sodium citrate tribasic dihydrate and disodium tartrate dihydrate at (298.15, 308.15 and 318.15) K. Methods: Two methods used in the present study are specific conductance measurements and spectroscopy (NMR) studies. Results: From the specific conductance(κ), various parameters such as Critical Micelle Concentration (CMC), degree of ionization of micelle (α), standard Gibbs free energy (ΔG°m), enthalpy (ΔH°m), and entropy (ΔS°m) of micellization have also been calculated. Thermodynamic parameters related to the micellization process were also analyzed through NMR studies. Conclusion: The CMC values are influenced by the presence of food additive. The magnitude of CMC values increases with an increase in the concentration of food additive. In all the cases, enthalpy of micellization, ΔH°m values are found to be negative, whereas entropy of micellization, ΔS°m values are positive, which indicates that hydrophobic interactions play a major role in the micellization process. Moreover, NMR studies reveal that tartrate and citrate are more hydrated than glutamic acid and propionate, resulting in a more downfield shift.

Volumetric and aggregation properties of metformin hydrochloride in methanol in temperature range of (288.15–318.15) K

This manuscript is related to the study of volumetric and micellar properties of metformin hydrochloride (Met-HCl) in methanol in temperature range of (288.15–318.15) K. Conductometric and refractive index data was used to find CMC of drug. From conductometric data various thermodynamic variables were calculated which include free energy of micellization, entropy of micellization and enthalpy of micellization. Density measurements of different drug solutions at specified temperatures were utilized for the calculation of apparent molar volume, partial molar volume, Hepler's constant and partial molar expansivity. These parameters are important for getting an understanding about different types of interaction of drug in solution. Met-HCl showed strong solvophobic than electrostatic interaction with methanol and had a structure promoting effect on it which was apparent from positive value of partial molar volume, Hepler's constant and partial molar expansivity. Micellization process was spontaneous, endothermic and resulted in increase in entropy of system because Gibbs energy change was negative, enthalpy change and entropy changes were positive.

Investigation of surface adsorption and thermodynamic properties of 1-tetradecyl-3-methylimidazolium bromide in the absence and presence of tetrabutylammonium bromide in aqueous medium

The aggregation behavior of imidazolium-based long-chain ionic liquid 1-tetradecyl-3-methylimidazolium bromide [C14mim][Br] has been investigated in the absence and presence of (1, 2, and 5) mM tetrabutylammonium bromide (C4H9)4NBr at three temperatures (298.15, 308.15, and 318.15) K. The critical micelle concentration (CMC), surface parameters such as maximum surface excess concentration (), the minimum area surfactant monomer at the air/water interface (), surface tension at CMC () and surface pressure () are determined by employing conductivity and surface tension measurements. Various thermodynamic parameters of micellization such as standard free energy of micellization (), standard enthalpy of micellization (), and standard entropy of micellization () are calculated by utilizing the temperature dependence of CMC observed using conductivity study. Other thermodynamic parameters such as free energy of adsorption (Δ) and surface free energy () are also evaluated. Refractive index measurements and UV–vis spectroscopic studies have been utilized to confirm the values of CMC obtained via conductivity and surface tension measurements. FTIR spectroscopic studies signify the various interactions prevailing in the system constituting long-chain ionic liquid and electrolyte.