Methanol Water Mixed Solvent Research Articles

Viscosity of Sodium Polystyrenesulfonate with Cetyltrimethylammonium Bromide in the Mixture of Methanol and Water.

Viscosity of cetyltrimethylammonium bromide (CTAB) in the presence of sodium polystyrene sulfonate (NaPSS) in methanol-water mixed solvent media has been reported at 308.15 K. The results have been analyzed on the basis of a simple model based on the scaling theory of the viscosity of polyelectrolyte solutions put forward by Plucktaveesak et al. (J. Phys. Chem. B, 2003, 107, 8166-8171). The specific viscosity data obtained here for the CTAB-NaPSS couple in mixed solvent media agree very well with the predictions of the above model. It has been established that the fraction of free counterions of the polyelectrolyte can be conveniently recovered in these complex fluids.

The Role of Weak C–H···X (X = O, π) Interactions in Three 1-Hydroxy-2-naphthoic Acid Cocrystals with N-Containing Heteroaromatics: Structural Characterization and Synthon Cooperation

Herein, three novel cocrystals of 1-hydroxy-2-naphthoic acid: tetramethylpyrazine, 1-hydroxy-2-naphthoic acid:1,10-phenanthroline, and 1-hydroxy-2-naphthoic acid:1,4-bis(imidazol-1-ylmethyl)benzene (L2) were obtained by crystallization in methanol–water mixed solvent via a slow evaporation method. The cocrystalline products 1−3 were carried out by a range of techniques, including single-crystal X-ray diffraction, Fourier transform–infrared spectroscopy, elemental analysis, and thermogravimetric testing. We analyzed the crystal structures of the cocrystals 1−3 and found that weak interactions C–H···X (X = O or π) were of great importance in the process of self-assembly as well as strong and conventional hydrogen bonds (N–H···O, O–H···N, O–H···O), leading to a stable and diverse multidimensional supramolecular architecture. It is worth noting that a series of ring motifs with different sizes were explored in the crystal structures of the above complexes, such as R22(5), R22(7), R22(8), R23(13), R24(16), R44(16), R44(22), and so on. The classical and robust supramolecular synthon intermolecular bond between acid and pyridine (acid···pyridine) heterosynthon R22(7), commonly found in organic solids containing carboxylic acids with other N-containing heteroaromatics, was further demonstrated to be involved in the construction of the hydrogen-bond networks of cocrystal 1. The thermogravimetric technique used in this study proved that the mass losses of these three cocrystals were closely related to the strength of the hydrogen bonds in the package fraction.

Synthesis, supramolecular aggregation, and NIR-II phosphorescence of isocyanorhodium(i) zwitterions.

Development of new second near-infrared (NIR-II, 1000-1700 nm) luminophores is highly desirable, and d8 square-planar metal complexes with NIR-II phosphorescence have been rarely reported. Herein, we explore an asymmetric coordination paradigm to achieve the first creation of NIR-II phosphorescent isocyanorhodium(i) zwitterions. They show a strong tendency for aggregation in solution, arising from close Rh(i)⋯Rh(i) contacts that are further intensified by π-π stacking interactions and the hydrophilic-hydrophobic effect. Based on such supramolecular aggregation, zwitterions 2 and 5 are found to yield NIR-II phosphorescence emissions centered at 1005 and 1120 (1210, shoulder) nm in methanol-water mixed solvents, respectively. These two bands show red shifts to 1070 and 1130 (1230, shoulder) nm in the corresponding polymer nanoparticles in water. The resulting polymer nanoparticles can brighten in vivo tumor issues in the NIR-II region with a long-circulating time. In view of the synthetic diversity established by the asymmetric coordination paradigm, this work provides an extraordinary opportunity to explore NIR-II luminophores.

Preparation of a porphyrin-polyoxometalate hybrid and its photocatalytic degradation performance for mustard gas simulant 2-chloroethyl ethyl sulfide

By combining 5,10,15,20-tetra(4-chlorine)phenylporphyrin (TClPP) and α-Keggin polyoxometalate H5PV2Mo10O40 (H5PVMo) via a simple ion-exchange method, an organic-inorganic hybrid material [C44H28N4Cl4]1.5[H2PMo10V2O40]·2C2H6O (H2TClPP-H2PVMo) was prepared and thoroughly characterized by a variety of techniques. The homogeneous photocatalytic degradation of 2-chloroethyl ethyl sulfide (CEES) (5 µL) by H2TClPP-H2PVMo (1 × 10−6 mol/L) was studied in methanol and methanol-water mixed solvent (v/v = 1:1), in which the degradation rate of CEES reached 99.52% and 99.14%, respectively. The reaction followed first-order reaction kinetics, and the half-life and kinetic constant in methanol and the mixed solvent were respectively 33.0 min, −0.021 min−1 and 15.7 min, −0.043 min−1. Mechanism analysis indicated that under visible light irradiation in the air, CEES was degraded via oxidation and alcoholysis/hydrolysis in methanol and the mixed solvent. O2·− and 1O2 generated by H2TClPP-H2PVMo selectively oxidized CEES into a nontoxic sulfoxide. Singlet oxygen capture experiments showed that H2TClPP-H2PVMo (ϕ = 0.73) had a higher quantum yield of singlet oxygen than TClPP (ϕ = 0.35) under an air atmosphere and visible light irradiation.

Spectrophotometric study of the sodium dodecyl sulfate in the presence of methylene blue in the methanol–water mixed solvent system

The methylene blue (MB) dye is very sensitive to changes in the polarity of its surroundings. The interaction of MB with sodium dodecyl sulfate (SDS) was studied spectrophotometrically in 0.1, 0.2, 0.3 and 0.4 vol fractions of methanol in an aqueous medium. The dielectric constant value decreases with the addition of methanol in the water and hence there is the lower stabilization of the lowest unoccupied molecular orbital which results in the hypsochromic shift in the monomeric form of methylene blue. In a 0.1 vol fraction of methanol, the peaks are seen at 665 and 612 nm, which are monomeric and dimeric MB peaks, respectively. The dimerization of MB is reduced with the increasing volume fraction of methanol in the solvent and ceases at/above 0.3 vol fraction of methanol. In the 0.4 vol fraction of methanol, the turbidity appears with the addition of SDS and there were no significant changes in the absorbance. In the presence of methanol, MB prefers to stay with the sulfate groups of SDS at the peripheral regions of the premicelle and micelle. At very low surfactant concentrations, far below their critical micelle concentration (CMC), the formation of MB-MB dimers and/or MB-SDS ion pairs or clusters occurs, and a corresponding shift in absorption and decrease in absorbance is observed. On increasing the concentration of SDS, micellization occurs, which disrupts the MB-MB dimers and MB-SDS ion pairs are incorporated with the micelles. On further addition of SDS, lone MB monomers become associated with these micelles and the absorbance increases slightly higher than those of the original dye in the solvent. This is the case of dye solubilization where monomers are completely incorporated or bounded by micelles. The CMC of SDS decreases in the presence of dye suggesting the strong interaction between the oppositely charged dye-surfactant ion pairs. The value of binding constant and partition coefficient decreased with the increasing volume fraction of methanol. The negative value of ΔGb indicates that the interaction between SDS and MB is spontaneous but the negative values of ΔGb decreased with the increasing volume fraction of methanol.

Physicochemical Studies on the Interaction between Sodium Dodecyl Sulfate and Methylene Blue in Methanol-Water Mixed Solvent Media

The surface activity and the process of micellization of sodium dodecyl sulfate (SDS) with methylene blue (MB) in a methanol-water mixed solvent system were investigated by tensiometry and conductometry at 298.15 K. The measurements of surface tension and conductivity of SDS-MB complex were carried up to 0.3 volume fractions of methanol because the resulting complex appeared turbid above 0.3 volume fractions of methanol. The critical micelle concentration (CMC) of the SDS was determined from both tensiometry and conductometry. The CMC of SDS increased with the increasing volume fraction of methanol due to the inclusion of methanol in the micelles and decreased in the presence of methylene blue due to the reduction of electrostatic repulsion within the anionic moiety of SDS by the positive charge of the added dye. Different properties like surface excess concentration Γ max , minimum surface area A min , Gibbs free energy of micellization Δ G m o , surface pressure ( π CMC ), efficiency of a surfactant ( p C 20 ), packing parameter P , and standard free energy interfacial adsorption Δ G ads o of SDS in the absence/presence of MB were calculated. On the basis of Δ G m o values, it was noticed that the increasing volume fraction of methanol disfavors the micellization of SDS, while the presence of MB increased the efficiency of SDS making the micellization process more spontaneous.

Two-stage liquefaction of sewage sludge in methanol-water mixed solvents with low-medium temperature

Hydrothermal liquefaction could be a promising technology to convert sewage sludge into bio-oil for energy recovery. In this study, in order to obtain the maximum yield of bio-oil and improve the energy recovery of sludge, the influence of temperature and residence time on the multi-temperature continuously liquefaction of sludge in methanol-water mixed solvents was investigated. The results showed that the two-stage liquefaction significantly affected the yield, elemental composition, higher heating value, energy recovery and chemical composition of bio-oil. By optimizing the reaction conditions of hydrothermal liquefaction, the maximum utilization of sludge resources was realized. The maximum yield (42.2 %) and ester content (41.8 %) of bio-oil were obtained when the reaction conditions were 260 °C, 40 min for the first stage and 340 °C, 40 min for the second stage. The migration and transformation of nitrogen indicated that nitrogen elements were mainly concentrated in the liquid product and the N-heterocyclic compounds are the main forms of nitrogen in bio-oils.

Correlation of the Volumetric Properties of Uni-Univalent Electrolytes in Methanol–Water Mixed Solvent Media: A Pitzer Ion-Interaction Approach

Although for a long time considerable attention has been paid to correlating the apparent molar volumes of electrolytes using the Pitzer ion-interaction approach in aqueous solutions, no attempt has, so far, been made to describe the volumetric data of electrolytes in mixed solvent media. This is due to the lack of experimental data on the pressure dependence of the dielectric constant in mixed solvent media. These data are essential to obtain the Debye–Huckel limiting law slopes for volumes that, in turn, are required to analyze the apparent molar volume vs. molality data of electrolytes in the light of the Pitzer ion-interaction approach. Here, we develop a convenient method which helped correlate the apparent molar volumes of electrolytes and estimate the Pitzer ion-interaction parameters for volume along with the Debye–Huckel limiting law slope for volumes. In particular, we have applied this approach to the literature apparent molar volume data of a number of uni-univalent electrolytes (viz., lithium chloride, sodium chloride, potassium chloride, sodium bromide, potassium bromide, sodium iodide, and potassium iodide) in methanol–water mixed solvent media at different temperatures. The parameters (namely, the apparent molar volume of the electrolyte at infinite dilution, $$V_{{\phi {\text{,MX}}}}^{\infty }$$ , the second virial coefficient $$B_{{{\text{MX}}}}^{V}$$ , and the third virial coefficient, $$C_{{{\text{MX}}}}^{V}$$ ) obtained here satisfactorily describe the molality dependence of apparent molar volumes of the investigated electrolyte solutions. The present correlation indicates that the electrolytes exist essentially as free ions in methanol–water mixed solvent media in conformity with what inferred earlier from conductivity measurements.

Synthesis and magnetic behavior of prussian blue analogues Mn3[Fe(CN)6]2·12H2O porous nanoparticles

Prussian Blue Analogues Mn3[Fe(CN)6]2·12H2O porous nanoparticles have been achieved by coprecipitation method and using polyvinyl pyrrolidone (PVP) as a protective matrix. The obtained nanoparticles were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TG), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). The X-ray diffraction measurement results show that all the obtained nanoparticles are face centered cubic structure. The infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS) measurement results indicate that Mn3[Fe(CN)6]2·12H2O nanoparticles are mixed-valence, and the ratios of MnIIFeIII to MnIIIFeII in obtained nanoparticles are different in water and water-methanol mixed solvent. The magnetic studies of nanocubes (about 480 nm, coming from water synthesis) and nanospheres (about 200 nm, from co-solvent synthesis) materials show that both samples have spin-glass behavior, but magnetic property measurement results indicated Tc, Tb and Tg temperatures of Mn3[Fe(CN)6]2·12H2O decreases as the size of nanoparticle reduces.

A multi-functional 3D polymolybdate-based copper(II) complex based on an asymmetric pyridyl-amide ligand: synthesis, structure and properties

A polymolybdate-based metal–organic compound {H2[Cu2(L)2(Mo8O27)(H2O)4]} (1) [L = N-(pyridin-3-yl)isonicotinamide] has been synthesized under solvothermal (methanol–water mixed solvent) conditions and structurally characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 3D metal–organic network containing unusual 1D [Mo8O27] 6− inorganic chains, with adjacent 1D chains connected by Cu(II) atoms and L ligands to form a 3D framework with a trinodal 4,4,6-connected {42.63.8}2{44.68.83} topology. The electrocatalytic activities of compound 1 and its photocatalytic properties for the degradation of organic dyes have also been investigated.

Testing of the effect of parameters on the cononsolvency of random copolymer gels of N-isopropylacrylamide and N-ethylacrylamide in methanol-water mixed solvents by simple gravimetric method

Random copolymer gels of N-isopropylacrylamide (NIPAM) and N-ethylacrylamide (NEAM) were synthesized in using different monomer compositions in 1:1 methanol-water mixtures and in pure water. The samples were characterized by cononsolvency study in methanol-water mixtures at various temperatures by swelling ratio measurements. It is observed that with the variation of the temperature and monomer compositions in the synthesis reaction mixture, the cononsolvency properties varied significantly. But the variation in the solvents compositions by keeping monomer compositions fixed does not affect the cononsolvency much. All results can be explained on the basis of the differences in thermoresponsive character or difference in the hydrophilicity of PNIPAM and PNEAM in water, preferential adsorption of the solvents by polymer networks, solvent-solvent interactions, heterogeneity of the polymer networks synthesized at different solvent compositions and at different temperatures, difference in their morphological properties, etc.

Liquid eutectic GaIn as an alternative electrode for PTB7:PCBM organic solar cells

Conventional vacuum deposition process of aluminum (Al) is costly, time-consuming and difficult to apply to the large-scale production of organic photovoltaic devices (OPV). This paper reports a vacuum-free fabrication process of poly[[4,8-bis(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thienophenediyl]:[6,6]-phenyl C71 butyric acid methyl ester (PTB7:PCBM) bulk heterojunction organic solar cell with liquid eutectic gallium–indium (EGaIn) electrode as an alternative to the common Al electrode. The insertion of a thin poly(ethylene oxide) (PEO) layer after depositing organic photoactive layer could help prevent the diffusion of liquid EGaIn into the active layer and allow the deposition of the EGaIn electrode. The PEO interfacial layer was formed by spin-coating from a mixed solvent of alcohol and water. Among different alcohol+water (methanol, ethanol, ethylene glycol, n-propanol, isopropanol, and isobutanol) mixed solvent tested, the n-propanol+water mixed solvent showed the greatest enhancement to the performance of OPVs. The improved device performance was attributed to the reactivity of mixed solvent n-propanol+water toward the surface of PTB7:PCBM active layer, which could help optimize surface morphology.

Metal ions induced various polymolybdate-based metal–organic complexes with a pyridyl-amide-carboxylate ligand: Synthesis, structures and selective separation of cationic dyes

Three polymolybdate-based metal–organic complexes (MOCs) constructed from a pyridyl-amide-carboxylate ligand, 6-(pyridine-3-ylcarbamoyl)picolinic acid (HPPA), namely, H2[Cd2(PPA)2(H2O)2](β-Mo8O26)·2CH3OH·9H2O (1), H2[Co4(PPA)2(H2O)12(Mo10O34)]·6H2O (2), [Ni4(PPA)4(H2O)6(β-Mo8O26)]·8H2O (3), have been successfully synthesized under solvothermal (methanol–water mixed solvent) conditions. Characterized by single-crystal X-ray diffraction analyses, 1 exhibits a 3D supramolecule framework, which is built from binuclear [Cd2(PPA)2(H2O)2]2+ subunits and β-[Mo8O26]4− anions through the non-covalent interactions; In 2, CoII was used and the [Mo10O34]8− anion was in situ constructed, which were linked by [Co2(PPA)(H2O)6]3+ subunits to yield a 1D double chain. The 1D chains were further linked by H-bond to afford a 3D supramolecular framework; 3 is also a 3D supramolecular structure based on 1D [Ni2(PPA)2(H2O)2(β-Mo8O26)]2− anionic chains and the free [Ni2(PPA)2(H2O)4]2+ units with the H-bond interaction. The adsorption behaviors for organic dyes of the title complexes were investigated. All the title complexes show efficient adsorption capacity for cationic dyes methylene blue (MB) and gentian violet (GV), especially complex 3 can selectively separate MB and GV from the mixture of MB&MO/GV&MO, respectively. In addition, the electrochemical properties of the title complexes also have been reported.

Cationic and anionic surfactants interaction in water and methanol–water mixed solvent media

The micellar properties between dodecyltrimethylammonium bromide (DTAB) and sodium dodecylsulfate (SDS) in water and 0.10, 0.20, and 0.30 volume fractions of methanol in methanol–water mixed solvent media have been studied by conductivity and surface tension measurements at 293.15 K. The concentration of dodecyltrimethylammonium bromide varied from 0.0001 to 0.03 mol·L− 1 in the presence of ~ 0.01 mol·L− 1 sodium dodecylsulfate and the concentration of sodium dodecylsulfate varied from 0.001 to 0.015 mol·L− 1 in the presence of ~ 0.005 mol·L− 1 dodecyltrimethylammonium bromide. Hence, the concentrations of cationic rich (DTAB–SDS) and anionic rich (SDS–DTAB) solutions have been taken in the ratio of 3:1. The critical micelle concentrations (cmc) of DTAB–SDS and SDS–DTAB solutions have been determined by conductivity and surface tension measurements at 293.15 K. The physicochemical properties such as Gibb's free energy of micellization (ΔGmo), free energy of surfactant tail transfer (ΔGtranso), maximum surface excess concentration (Гmax), area occupied by surfactant molecule (Amin), surface pressure at the cmc (πcmc), packing parameters (P) and standard free energy interfacial adsorption (ΔGadso) are calculated in water, 0.10, 0.20 and 0.30 volume fractions of methanol–water at 293.15 K. Addition of methanol significantly affects the physicochemical properties between DTAB and SDS. With increasing concentration of methanol, the cohesive force and the dielectric constant decrease that affects the micellization and other physicochemical properties. The micellization between DTAB and SDS have been assessed in terms of different solvent parameters. The ratio of the solvent surface tension to the limiting surface tension at the cmc has been used as the solvophobic effect.

Effect of Different Low‐Molar Mass Electrolytes on the Viscometric Behaviour of Sodium Polystyrenesulfonate in Methanol–Water Mixed Solvent Media

SummaryPrecise measurements on the viscosities of sodium polystyrenesulfonate (NaPSS) in water as well as in methanol–water mixed solvent media have been reported in presence of NaCl, KCl, NaBr and KBr having concentrations of 0.1 and 0.5 mol.L−1 at 308.15 K with the polyelectrolyte concentrations in the range ∼ 0.001 to ∼ 0.012 eqv L−1. The reduced viscosities of the polyelectrolyte solutions vary linearly with polymer concentration for all the systems investigated which enabled us to determine the intrinsic viscosities of sodium polystyrenesulfonate in methanol–water mixtures using the Huggins equation. The coiling of the polyion chains are found to increase in the order: NaPSS‐NaCl < NaPSS‐NaBr < NaPSS‐KCl < NaPSS‐KBr. The solvodynamic dimensions of the polyion coils are found to be reduced as the relative permittivity of the medium decreases. The present study also indicates that the polyion structures become more compact with increasing salt concentration in the medium.

PH, solvent and metal ion induced octamolybdate-based metal–organic complexes decorated with a pyridyl-carboxylate ligand containing an amide group

Three octamolybdate-based metal–organic complexes constructed from a pyridyl-carboxylate ligand containing an amide group, 3-(2-pyridinecarboxylic acid)amido pyridine (HPCAP), namely, H2{[Cu3(PCAP)4(H2O)2](β-Mo8O26)}·10H2O (1), H{[Cu(PCAP)(H2O)](β-Mo8O26)0.5} (2) and H2[Co(H2O)6][Co2(PCAP)4(γ-Mo8O26)(H2O)2]·10H2O (3), have been successfully synthesized under hydrothermal or solvothermal (methanol–water mixed solvent) conditions. Single-crystal X-ray analyses reveal that compound 1 is a 2D layer based on infinite 1D [Cu3(PCAP)4]n2n+ chains and bidentate β-Mo8O264− anions. In compound 2, 1D “thin centipede” [Cu2(PCAP)2]n2n+ chains were connected by tetradentate β-Mo8O264− anions through the Cu–O bond to form a 2D network. In compound 3, γ-Mo8O264− anions were connected by adjacent [Co2(PCAP)4(H2O)2] moieties through Co–O and Mo–N bonds forming an uncommon 1D “fat centipede” chain. The adjacent chains were further extended to a 2D supramolecular network through hydrogen bonding interactions. The title compounds represent the first examples of introducing a pyridyl-carboxylate ligand containing an amide group into the POM system. The pH value, solvent and metal ions play key roles in the construction of the final architectures and show a great influence on the structural diversities of the title compounds. The electrochemical properties of compound 1 and the photocatalysis properties of the title compounds have been reported.

Effect of Methanol on Viscosity of Aqueous Solutions of Cationic Surfactants at 298.15 to 323.15 K

Viscosity measurements have been made to the solutions of dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB) in 0.10, 0.20, 0.30, and 0.40 volume fractions of methanol in methanol-water mixed solvent media at 298.15, 308.15, 318.15, and 323.25 K. Critical micelle concentration (CMC) values have been determined. From relative viscosity for surfactant solutions, related viscosityBcoefficients are calculated and the values are interpreted in terms of solute-solvent interactions.

Micellization behavior of mixed surfactants in pure water and methanol-water mixed solvent media by density methods

The properties of anionic-rich and cationic-rich mixtures of dodecyltrimethylammonium bromide (DTAB) and sodium dodecylsulfate (SDS) in pure water and methanol-water mixed solvent media were studied using density measurements at room temperature. The results showed that density increases with increasing concentration of surfactant mixture over the entire concentration range investigated in pure water and in the given mixed solvent media and which are found to decrease with an increase in the volume fraction of methanol in the solvent composition. The critical micelle concentration increases with the increase in volume fraction of methanol for both the anionic-rich (SDS-DTAB) and cationic-rich (DTAB-SDS) systems.BIBECHANA 13 (2016) 114-120

A turn-on Rhodamine B-indole based fluorogenic probe for selective sensing of trivalent ions

An indole functionalized Rhodamine based fluorophoric probe (L) rendered selective colorimetric as well as turn-on fluorescence responses toward trivalent metal cations (Al3+, Fe3+ and Cr3+) over a variety of divalent and monovalent metal ions in 1:1 methanol–water mixed solvent. These selective colorimetric and fluorescence responses were explained as a consequence of spirolactam ring opening due to the protonation of L, where the lower Ksp values of M3+ (Al3+, Fe3+ and Cr3+) assisted the generation of H+ through hydrolysis in mixed aqueous medium. The turn-on fluorescence response of L towards M3+ is also visually detectable in test paper strips.

Studies of the Micellization of Cationic–Anionic Surfactant Systems in Water and Methanol–Water Mixed Solvents

Measurements of the conductance of binary mixtures of cetyltrimethylammonium bromide and sodium dodecylsulfate in pure water and in methanol–water mixed solvent media containing 0.10, 0.20, and 0.30 volume fractions of methanol at 308.15, 318.15, and 323.15 K are reported. The concentration of sodium dodecylsulfate varied from 0.001 to 0.04 mol·L−1 in the presence of ~5.0 × 10−4 mol·L−1 cetyltrimethylammonium bromide. The results showed a sharp increase in the conductance with increasing concentrations of the surfactant mixture. The conductance is found to increase with increasing temperature over the entire concentration range in pure water and in a given mixed solvent medium but is found to decrease with increasing methanol content in the solvent. Estimation of the pre-cmc (S 1) and post-cmc (S 2) slopes for the CTAB–SDS system, to calculate the critical micelle concentration, provides important insight regarding the solution behavior of the mixed surfactants. The critical micelle concentration (cmc) and degree of micellar dissociation (α) of sodium dodecylsulfate in the presence of cetyltrimethylammonium bromide increase in the methanol–water mixed solvent medium. Additionally, the values of cmc and α increase with increasing temperature. The thermodynamic functions for the micellization were calculated at various conditions.