Standard Enthalpy Of Micellization Research Articles

Effect of percentage of methanol on micellization position of mixed surfactant interaction in the absence and presence of dye

The interaction behavior of mixed surfactant-dye systems, i.e., anionic surfactant sodium dodecyl sulfate (SDS), cationic surfactant cetyl pyridinium chloride (CPC), and dye methyl orange (MO) was investigated through the allocation of micelles using conductivity measurements. Conductivity as a function of surfactant concentration was monitored to calculate the critical micelle concentration (CMC). The conductivity increased sharply as the surfactant content increased, according to the results. Moreover, the conductivity rises with temperature, whereas it falls with increased methanol (CH3OH). CH3OH-H2O mixed solvent media containing 0 %, 10 %, 20 %, and 30 % of CH3OH at 298.15, 308.15, and 318.15 K to work out the basic micelle fixation, gives significant understanding to the arrangement of the mixed surfactants. The CMC and degree of micellar dissociation (α) of SDS with CPC increase in the CH3OH and H2O mixture. The CMC and α values are increased by increasing the temperature. Various thermodynamic parameters, i.e. Standard free energy of micellization (ΔGmo), Standard enthalpy of micellization (ΔHmo), and Standard entropy of micellization (ΔSmo) were computed in SDS-CPC without MO. ΔGmo values for SDS-CPC in the presence of MO results in micellization more probable with MO.

Solubilization and physicochemical parameters of 2-chloro and 4-chlorophenol in micellar media of cetyltrimethylammonium bromide and sodium dodecyl sulphate at different temperatures

Solubilization and thermodynamic parameters of 2-chloro and 4-chlorophenol in micellar media of Cetyltrimethylammonium bromide (CTAB) and Sodium dodecyl sulphate (SDS) are elaborated in this study. The effect of the addition of 2-chloro and 4-chlorophenol on the critical micelle concentrations (CMCs) of CTAB and SDS was investigated by using the conductivity method at different concentrations (5 mmolL−1 to 25 mmolL−1) and temperatures (25 °C to 45 °C). The plot of specific conductance versus concentration of surfactant was used to determine CMC value. The CMC values of CTAB and SDS were observed to decrease, and thus the addition of 2-chloro and 4-chlorophenol favors micellization. In addition, it was observed that the CMC values of CTAB and SDS gradually increased with an increase in temperature. Various types of thermodynamic parameters such as standard Gibbs free energy of micellization (ΔGm°), standard enthalpy of micellization (ΔHm°) as well as standard entropy of micellization (ΔSm°) were determined and explained thoroughly to investigate the interactions between additives and surfactant. The magnitudes of ΔGm°andΔHm° were shown to be negative in the whole system, which shows that the processes of micellization were energetically spontaneous and exothermic. The thermodynamic parameters of transfer (ΔGm.tr°, ΔHm.tr° and ΔSm.tr°) from water to 2-chloro and 4-chlorophenol were also calculated and discussed with appropriate reasoning.

Inquisition of micellar and surface active properties of gemini surfactants in the presence of a dipeptide

Abstract The influence of dipeptide glycyl-l-valine (gly-l-val) on the micellization and surface active properties of two different gemini surfactants varying in their spacer group i.e. ethylene-1,2-bis (N,N-dimethyl-N-dodecylammonium bromide) (12–2–12) and hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) (12–6–12) was explored using tensiometry as well as conductivity technique. Conductivity measurements at several temperatures (293.15, 298.15, 303.15 and 308.15) K and tensiometric measurements at 298.15 K at several concentrations of dipeptide (0.02, 0.04 and 0.06) mol/kg were conducted so as to deduce the interactions amid dipeptide and two surfactants. Several parameters viz. critical micelle concentration (CMC) as well as the degree of ionization (α) along with various parameters associated with thermodynamics; standard entropy of micellization ( Δ S m 0 ${\Delta}{S}_{m}^{0}$ ), Gibbs free energy of micellization ( Δ G m 0 ${\Delta}{G}_{m}^{0}$ ) and standard enthalpy of micellization ( Δ H m 0 ${\Delta}{H}_{m}^{0}$ ) have been evaluated through conductivity data. Various additional thermodynamic parameters such as free energy of adsorption ( Δ G a d 0 ${\Delta}{G}_{ad}^{0}$ ) and surface free energy ( G min s ${\left(G\right.}_{\mathrm{min}}^{s}$ ) have been also estimated through surface tension measurements.

Interaction between oxidised state of quercetin and bovine serum albumin in presence of surfactant aggregates with different charges

The present investigation focuses on the role of surfactant and its charge on the interaction of flavonoid Quercetin (QCT) and Bovine serum albumin (BSA). QCT is known to undergo autoxidation in many chemical environments which has different characteristics compared to its non-oxidised structure. In this experiment, two ionic surfactants used. They are anionic surfactant, Sodium dodecyl sulfate (SDS) and Cationic surfactants Cetyl pyridinium bromide (CPB). The characterizations employed are conductivity, FT-IR, UV–visible spectroscopy, Dynamic light scattering (DLS) and Zeta potential measurements. The critical micellar concentration (CMC) as well as the counter-ion binding constant (β) have been calculated by making use of specific conductance values, in aqueous medium at 300 K. Various thermodynamic parameters, ΔG0 m, standard free energy of micellization, ΔH0 m, standard enthalpy of micellization and ΔS0 m, standard entropy of micellization are calculated. The negative value of ΔG0 m in all systems is indicative of spontaneous binding occurring in both QCT + BSA + SDS (−23.35 kJ mol−1) and QCT + BSA + CPB (−27.18 kJ mol−1). The higher negative value infers the latter is a more stable system with greater spontaneity. The UV-visible spectroscopy study points at stronger binding of QCT and BSA in presence of surfactants and also there is stronger binding of CPB in ternary mixture with higher binding constant compared to SDS ternary mixture. Which is evident from the binding constant calculated from Benesi-Hildebrand plot (QCT + BSA + SDS, 244.46 M−1; QCT + BSA + CPB, 336.53 M−1). Further, the structural alterations occurring in the above systems has been observed by FT-IR spectroscopy. The DLS and Zeta potential measurements also support the above finding. Communicated by Ramaswamy H. Sarma

Micellization pattern of cationic surfactants in presence of azo dye in methanol mixed media

Conductivity measurements at three different temperatures (298.15, 308.15, and 318.15 K) were performed to determine the micellization nature of cationic surfactants, i.e., dodecyl trimethylammonium bromide (DTAB) and cetylpyridinium chloride (CPC), in the absence and presence of the azo dye methyl red (MR) in four mixed solvent systems (0.1 to 0.4) volume fraction of methanol in water. We calculated the critical micelle concentration (CMC) of DTAB and CPC and the degree of ionization (α) for both in the absence and presence of MR using William’s method. The interaction of surfactants DTAB and CPC with MR has been identified separately through the dye-surfactant aggregation process, with reduced CMC values due to the molecular reorientation of methyl red in the systems. Micellization becomes more likely with MR due to the formation of a molecular complex in mixed systems. We calculated different thermodynamic properties both in the absence and presence of methyl red. Such parameters are the standard Gibbs free energy of micellization (ΔGmo), the standard enthalpy of micellization (ΔHmo), the standard entropy of micellization (ΔSmo), the standard free energy of transfer (ΔGtranso) and heat capacity of micellization (ΔmCp0). In accordance with ΔGmo values, the mixtures show the spontaneous nature of micellization of DTAB and CPC with MR as well.

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).

Investigation of aggregation and surface active properties of cationic Gemini surfactants in the presence of antidepressant drug

The aggregation and interfacial behavior of two Gemini surfactants ethylene-1, 2-bis (N, N-dimethyl-N-tetradecylammonium bromide) (14-2-14) and ethylene-1, 2-bis (N, N-dimethyl-N-dodecylammonium bromide) (12-2-12) have been scrutinized in absence and presence of antidepressant drug Nortriptyline Hydrochloride (NH) having concentrations (0.10, 0.15 and 0.25) mmol/kg through surface tension measurements at 298.15 K and via conductivity measurements at 293.15, 298.15, 303.15 and 308.15 K. Various surface active parameters such as minimum surface area per surfactant molecule (Amin), surface tension at CMC (γcmc), maximum surface excess concentration (Γmax), surface pressure (ᴨcmc), and CMC of the studied systems of surfactants and NH have been determined from surface tension measurements. Different parameters like degree of ionization (α) inclusive of CMC and thermodynamic parameters of micellization like standard enthalpy of micellization (ΔHm0), standard entropy of micellization (ΔSm0) and Gibbs free energy of micellization (ΔGm0) have been attained using conductivity measurements. Since these Gemini surfactants have improved surface activity in comparison to monomeric conventional surfactants, they can enhance permeability of drugs through bio membranes which make them better drug carriers in contrast to prevailing solutions.

Study of Solvation Behavior Thermodynamics and FT-IR Spectroscopic Analysis of N-Butylethanolammonium Based Ionic Liquids with Polar Solvents

The effect of anion geometry on aggregation behavior of surfactant with aqueous solutions was investigated by the systematic measurements of concentration, temperature dependent density and derived thermodynamic properties. In this work, N-Butylethanolammonium trifluoroacetate [BEATFA] and N-Butylethanolammonium nitrate [BEAN] ionic liquids (ILs) were synthesized and characterized by 1H NMR. The binary systems IL+water/ethanol were prepared for the concentration ranges from 0.0264 to 0.4621 mol·kg−1 and the temperature ranges from 298.15 K to 318.15 K. Further, the apparent molar volume (Vɸ), partial molar volume (Vɸ∞), thermal expansion coefficient (α) and apparent molar expansivity (Eɸ) were derived from the experimentally measured density data. The critical aggregation concentration (cac), apparent molar volume at critical aggregation concentration (Vɸ,CAC), apparent molar volume in aggregation phase (Vɸ,mic), change in apparent molar volume due to aggregation (∆Vɸ,m) and degree of ionization (α′) were derived from the plot of apparent molar volume versus inverse of ILs concentration. The thermodynamic aggregation properties such as standard Gibb's free energy of micellization (∆Gom), standard enthalpy of micellization (∆Hom) and standard entropy of micellization (∆Som) were calculated from experimental measurements. The sign and magnitude of apparent molar volume at infinity dilution reveals about IL+solvent or IL-IL interactions between the component molecules. The system [BEAN]+water showed lowest positive magnitude in both Vɸ∞ and cac than compare to [BEATFA]+water due to the formation of stronger IL+solvent intermolecular interactions through the H-bonding. The variance in observed Vɸ∞ and cac data with different solvents due to the solvophobic effect and hydrogen bonding tendency was explained by FT-IR spectroscopy and DFT computational study. Among the all binary systems, [BEAN]+water showed highest intermolecular interaction tendency than other systems, the obtained results were compared with available literature data and analyzed in terms of intra and intermolecular interactions, polarity of solvents, hydrophobicity, nature anion, size and shape of the anion.

Micellization, acoustic and thermodynamic study of procaine in aqueous solution at different temperatures

Critical micelle concentrations (CMC) of procaine hydrochloride (PHCl) in aqueous solution has been determined from conductivity (κ), density (ρ) and speed of sound (u) measurements using Williams and Philips methods at the temperature range 298.15–318.15 K intervals of 5 K.The CMC values found by these two methods using the speed of sound, density and conductivity data were in good agreement at all temperature. As the applied temperature increases, the CMC increases, owing to the lower probability of hydrogen bond formation at higher temperatures.The obtained values of the standard Gibbs energy of micellization (ΔGmo) and the standard enthalpy of micellization (ΔHmo) are negative at all investigated temperatures. Thus, one can say that the micellization process and the relationship between drug-water interactions and solute-solute interactions occur at different temperatures. Negative ΔGmo values were recorded when the systems become more hydrophobic. The negative increase in ΔHmo by the increased temperatures can be explained by the exothermic nature of the micellization process. The obtained values of the entropy for micellization (ΔSmo) are positive at all temperatures. The ΔSmo values decrease with temperature increase, this result interpreted as micellazation tend to be energy driven at higher temperatures.Apparent molar volume (V∅), apparent molal volumes at ınfinite dilution (V∅0), micellar apparent molal volumes (V∅mic), changes in apparent molal volumes upon aggregation (ΔVm), apparent molar isentropic compressibilities (K∅(S)), isentropic apparent molal adiabatic compressibilities at infinite dilution (K∅(S)0), micellar ısentropic apparent molal adiabatic compressibilities (K∅(S)m) and changes in isentropic apparent molal adiabatic compressibilities (ΔK∅(S)) of procaine in aqueous solution have been calculated by combining the speed of sound and density measurements. ΔVm are estimated and found to be negative except for 0.43 m3mol−1 (maximum value) at 318.15 K. The variations in these parameters were discussed for micellization process and drug-water interactions and solute-solute interactions at different temperatures.

Alterations induced in the micellization behavior of dioctyl sodium sulfosuccinate in the presence of imidazolium-based surface-active ionic liquids in aqueous medium

The present work describes the effect of 1-nonyl-3-methylimidazolium bromide [C9mim][Br] and 1-dodecyl-3-methylimidazolium bromide [C12mim][Br] on aggregation behavior of anionic surfactant dioctyl sodium sulfosuccinate (NaAOT) in aqueous medium by employing different techniques such as conductivity measurement, UV–Visible spectroscopy and FT-IR spectroscopy. The conductivity data of anionic surfactant in the aqueous solution of surface-active ionic liquids is taken experimentally in the temperature range from 293.15 to 308.15 K with the interval of 5 K at various concentrations that is, (0.04, 0.08, 0.12, and 0.16) wt.% of both the SAILs. The critical micelle concentration (CMC) of NaAOT is detected to alter in the presence of both the SAILs. Temperature dependence of CMC obtained from conductivity measurements is utilized to evaluate various thermodynamic parameters of micellization such as, standard free energy of micellization (), standard enthalpy of micellization (), and standard entropy of micellization (). The UV–Visible spectroscopic study is utilized to confirm CMC values obtained from conductivity measurements, which are found to be in good agreement. FT-IR Spectra are recorded to analyze the structural changes that prevailed in both systems.

Influence of sodium bis(2-ethylhexyl) sulfosuccinate on the self-assembly of AOT based surface-active ionic liquids having different pharmacologically active cations in the aqueous medium

The aggregation behavior of three AOT based ionic liquids have been investigated in aqueous medium in the presence of different concentrations i.e. (0.04, 0.08, 0.12, 0.16) mM of sodium bis(2-ethylhexyl) sulfosuccinate (NaAOT) at different temperatures (298.15, 308.15, 318.15) K. The AOT based ionic liquids have been successfully synthesized by replacing the cation of sodium bis(2-ethylhexyl) sulfosuccinate (NaAOT) with various pharmacologically active cations such as cholinium [Cho]+, tetraethylammonium [TEA]+, and tetrabutylammonium [TBA]+. The conductivity and surface tension measurements have been employed to understand their aggregation behavior by evaluating various thermodynamic and surface-active parameters such as standard free energy of micellization (ΔGm0), standard enthalpy of micellization (ΔHm0), standard entropy of micellization (ΔSm0), surface pressure at cmc(á́¨cmc), maximum surface excess concentration (Γmax), the minimum area of surfactant monomer at the air/water interface (Amin), the standard Gibbs free energy of adsorption (ΔGad0) and the free energy of a surface at equilibrium (Gmins).

Scrutinizing the Micellization Behaviour of 14-2-14 Gemini Surfactant and Tetradecyltrimethylammonium Bromide in Aqueous Solutions of Betaine Hydrochloride Drug

In the present work, we investigated the effect of drug Betaine Hydrochloride (Betaine HCl) on the aggregation behavior of ethylene-1, 2-bis (N, N-dimethyl-N-tetradecylammonium bromide) (14-2-14) and tetradecyltrimethylammonium bromide (TTAB) by employing electrical conductivity and FT-IR spectroscopic techniques. Initially, synthesis of 14-2-14 is carried out in laboratory followed by determination of critical micelle concentration (CMC) through electrical conductivity measurements at temperatures 293.15 K, 298.15 K, 303.15 K, 308.15 K in absence and presence of Betaine HCl at concentrations 0.10 mmol/kg, 0.15 mmol/kg and 0.25 mmol/kg. The decrement in CMC value is observed with increasing concentrations of Betaine HCl as well as with decreasing temperatures. Several thermodynamic parameters such as the standard enthalpy of micellization (ΔH0m), the standard entropy of micellization (ΔS0m) and the standard Gibbs energy of micellization (ΔG0m), etc. have been evaluated using values of CMC for various concentrations of Betaine HCl at different temperatures. The alterations instigated in respective have been recognized by FT-IR spectroscopic analysis, which signifies the variations produced by the drug on the aggregation of the surfactants (14-2-14 and TTAB) in aqueous media.

Thermodynamic analysis of micelles formation of anionic surfactant SDS in the presence of aqueous and aqueous solution of ionic liquid 1‐butyl‐3‐methylimidazolium chloride

AbstractIn this study, the experimental conductivity, fluorescence, and UV spectroscopy study have been done for aqueous solutions of sodium dodecyl sulfate (SDS) and in aqueous ionic liquid (IL) 1‐butyl‐3‐methylimidazolium chloride [C4mim][Cl] solutions at a temperature of 298.15 K. Experimental conductivity measurement has been done at different temperatures from 298.15 to 308.15 K. Moreover, the critical micelle concentrations (CMCs) of the mentioned systems were determined by different methods; furthermore, the CMC values have been utilized to originate the values of thermodynamical parameters of micellization like standard enthalpy of micellization ( ), the standard free energy of micellization ( ), and standard entropy of micellization ( ). Fourier transform‐infrared (FT‐IR) spectra have been recorded to investigate the interactions and structural changes that occurred in the mixed system. Work has been discussed in terms of the effect of the aqueous IL solution on the micellization process of the SDS.

Investigations on the micellization behavior and thermodynamic characteristics of synthesized surface active ionic liquids [C14mim] [Br] and [C15mim] [Br] in the presence of oral antidiabetic drug metformin hydrochloride

The present examination focuses on understanding the micellization behavior of surface active ionic liquids 1-tetradecyl-3-methylimidazolium bromide [C14mim] [Br] and 1-pentadecyl-3-methylimidazolium bromide [C15mim] [Br] in presence of antidiabetic drug metformin hydrochloride by employing conductivity measurements and IR spectroscopy. The CMC value and value of counter ion dissociation (α) has been calculated by utilizing conductivity measurements. The dependency of CMC value evaluated from conductivity measurements in aqueous medium and presence of different weight percentage (0.03, 0.05 & 0.07) of drug metformin hydrochloride in aqueous medium and at different temperatures (298.15, 308.15 & 318.15) has been employed to calculate various thermodynamic parameters such as standard free energy of micellization (ΔGm0), standard enthalpy of micellization (ΔHm0), and standard entropy of micellization (ΔSm0). There is a significant increase in CMC value with the rise in temperature signifying delay in micellization process with increasing temperature. Further, the structural alterations prevailing in the selected system (ionic liquid-drug) has been determined by FT-IR Spectroscopy.

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.

Influence of tetra ethyl ammonium bromide (C2H5)4NBr on the aggregation behavior of surface active ionic liquid 1-tetradecyl-3-methylimidazolium bromide [C14mim][Br

In this work, we tend to explore the effect of organic electrolyte i.e. tetra ethyl ammonium bromide (C2H5)4NBr on the aggregation behavior of 1-tetradecyl-3-methylimidazolium bromide [C14mim][Br] by utilizing electrical conductivity measurement, refractive index measurement, UV–Visible spectroscopy as well as FT-IR spectroscopic study. First of all, the synthesis of [C14mim][Br] is carried out in the laboratory, then the critical micelle concentration (CMC) of [C14mim][Br] is determined using conductivity measurements at temperatures 298.15 K, 308.15 K and 318.15 K in the absence and presence of (C2H5)4NBr at different concentrations 1 mM, 2 mM and 5 mM. The reduction in value of CMC is observed with respect to increasing concentration of (C2H5)4NBr and with the increase in temperature, the value of CMC also increases. These results are observed due to the establishment of reinforced hydrophobic interactions between the hydrophobic parts of surface active ionic liquid and the electrolytes. Then we reflected different thermodynamic parameters such as, standard free energy of micellization (ΔGm0), standard enthalpy of micellization (ΔHm0), and standard entropy of micellization (ΔSm0) in the temperature range 298.15 K–318.15 K, utilizing the value of CMC obtained from conductivity measurements. A graphical contrast of these thermodynamic parameters has been made. Further refractive index measurement and UV–visible spectroscopic study have been employed to verify the CMC obtained using conductivity measurement, which is found to be very close to that obtained via conductivity study. The alterations produced in the respective system have been confirmed via FT-IR spectroscopic study, which signify the variations produced by electrolyte on the aggregation of surface active ionic liquid in aqueous media.

Induced Alterations in the Aggregation Behavior and Thermodynamic Properties of Anionic Surfactant Sodium Tetradecyl Sulfate (STS) in presence of Imidazolium Based Ionic Liquid in Aqueous Media: A Conductometric Study

Surfactants can be considered as an important class of chemical species having a polar head and non-polar tail, which make it capable to be utilized in many industrial formulations such as coatings, paints, lubricants, and cosmetics, etc. Also, ionic liquids, which are actually molten salts, are also having many useful properties such as negligible vapor pressure, high thermal stability, etc. They can modify the physiological as well as aggregation properties of conventional surfactants according to our desire. The mixtures of ionic liquids with a surfactant are found to be better systems for many industrial applications than individual ones. Thus the micellization behavior of sodium tetradecyl sulfate STS is investigated in the presence of 1-propyl-3-methylimidazolium bromide [C3mim][Br] in aqueous media. For this, ionic liquid 1-propyl-3-methylimidazolium bromide [C3mim][Br] is synthesized in our lab. Then the conductivity measurement is done to determine the critical micelle concentration (CMC) of sodium tetradecyl sulfate STS in the absence and presence of (0.02, 0.05 and 0.1) wt. %, of 1-propyl-3-methylimidazolium bromide [C3mim][Br] in aqueous medium at three different temperatures i.e. (298.15, 303.15 and 308.15) K. The results are then utilized to find the thermodynamic parameters of micellization such as, standard free energy of micellization, standard enthalpy of micellization, and standard entropy of micellization, which are important to understand the driving force behind the process of micellization.

Influence of Electrolyte and Temperature on the Aggregation Behaviour of Mixed System Consisting Drug and Anionic Surfactant

At present work, the interaction of amphiphilic drug promazine hydrochloride (PMZ) with anionic surfactant sodium dodecyl sulfate (SDS) and imipramine hydrochloride (IMH) with anionic surfactant dioctyl sulfosuccinate sodium salt (AOT) in the absence and presence of 50 mmol.kg−1 inorganic salt is investigated in aqueous medium at different temperatures. For this, conductometric measurements were carried out to evaluate the critical micelle concentrations (CMC) of drug and surfactant. Ideal critical micelle concentration (CMC id) and interaction parameter (β) has also been evaluated. The deviations obtained in values of CMC and CMC id indicate the interaction between drug and surfactant. Other micellar mole fraction parameters such as X1 Rub (Rubingh), X1 Mot (Motomura), X1 Rd (Rodenas) and X1 ideal (ideal mole fraction) are also evaluated based on different proposed models. Other thermodynamic parameters of micellization such as, standard free energy of micellization , standard enthalpy of micellization , and standard entropy of micellization are also evaluated based upon the equations already present in literature to understand the interactions prevailing in the studied systems.

Study on Interactions Between Imidazolium Based Surface Active Ionic Liquid and Drug at Different Temperature and Concentrations

The present study aims to investigate the molecular interactions of surface active ionic liquid (IL), 1-pentadecyl-3 methyl imidazolium bromide [C15mim]Br with drug chloramphenicol in aqueous solution. For this the conductivity measurements have been employed to indicate [C15mim]Br –chloramphenicol interactions. The evaluation of Micellar and interfacial parameters such as critical micelle concentration and various thermodynamic parameters such as standard free energy of micellization, standard entropy of micellization and standard enthalpy of micellization has been carried out.

Exploring the effect of hydrophobic ionic liquid on aggregation, micropolarity and microviscosity properties of aqueous SDS solutions

Ionic liquid (IL)-modified surfactant systems have versatile applications in several technological areas. Therefore, it is utmost need to achieve full understanding of interactions existing in such systems before their further uses. Here, the effects of IL, 1-ethyl-3-methylimidazolium hexafluorophospahte, [emim][PF6] on the physicochemical properties of aqueous sodium dodecyl sulfate (SDS) solutions has been studied using multi-technique approach. Various micellar parameters such as critical micelle con-centration (cmc), degree of counter ion dissociation (α), aggregation number (Nagg) as well as some thermodynamic parameters such as standard free energy of micellization (G°m), standard enthalpy of micellization (H°m) and standard entropy of micellization (S°m) and surface properties from surface tension measurement have been evaluated. A significant decrease in cmc, and increase in degree of counter ion dissociation along with increase in Nagg is observed. The aggregation behaviour of SDS is also studied in presence of ILs having different alkyl chain length in their imidazolium cations. A decrease in CMC of SDS observed, and trend of decrease in CMC is reported as [hmim][Cl] > [bmim][PF6] > [emim][PF6]. The micropolarity and microviscosity of micellar media are accessed with fluorescence probe studies. The effect of chain length of IL cation has been also explored on aggregation behaviour. The FTIR technique is employed to evaluate possible interactions between SDS and IL [emim][PF6] molecules, the information regarding size of SDS micelle in presence of IL [emim][PF6] has been explored by DLS technique.