Methanol-benzene Mixtures Research Articles

Surface Tension Studies of Ternary System: Cu (II) Surfactants-2-amino-6-methyl Benzothiazole Complex Plus Methanol Plus Benzene at 311 K

Background: Exact information about micellar feature of Cu (II) Soaps play a vital role in its selection in specific phenomena such as foaming, wetting, detergency, emulsification, etc. and also in their use as herbicides, fungicides, pesticides and insecticides. Copper soaps having a tendency of complex formation with the compounds containing donor atoms like N, O, Br, S, etc. It is well known that benzothiazoles are derivatives of anilines and play significant role in biological activities and having sufficient industrial and analytical applications. Objective: Coherence of biological activities of copper soaps and benzothiazole stimulated our interest to extend the studies in their cumulative form as complexes. It is anticipated that it will generate new hopes in the pharmacological activities. Critical micelle concentration, revelation of the nature and size of micelles formed and surface active properties have been investigated in the proximity of mixed solvents having wide difference in degree of polarity. Methods: Copper soap complex solutions in polar and non-polar solvent (methanol and benzene) mixtures have been chosen for the surface tension studies. Their micellar and colloidal behaviour have been analysed and these results confirm that CMC values depend upon composition of solvent mixture and are found to decrease with increase in chain length of copper surfactant (caprylate, caprate and laurate) in the referred molecule taken for study. Results: The results of surface tensions have been explained on the basis of Szyszkowski’s empirical equation and it is observed that X, Y and (-XlnY) lead to the confirmation of fact that the change in the behaviour of copper surfactant complex occurs differently at two different compositions (40% & 80%) of methanol-benzene mixture. The results reveals that the numerical value of X for all the complexes in 40% and 80% methanol-benzene mixture below CMC are higher than above CMC. The area covered by 1 g. mole of the complex decreases gradually from 40% methanol to 80% methanol. The values of parachor of the complex solution increase with increase in the mole fraction and volume percent of methanol below CMC and decrease above CMC. The plots of parachor against the mole fraction of the copper surfactant complex are characterized by an intersection of two straight-lines at the CMC of copper surfactant complex. Conclusion: Hammic and Andrew’s equations has been successfully applied to explain the behaviour of copper surfactant complex in two different compositions of methanolbenzene mixtures.

Characterization of Soil Particle Surfaces Using Adsorption Excess Isotherms

Measurement of adsorption excess isotherms of methanol-benzene mixtures was applied to the characterization of soil particle surfaces. The sorption capacity and Gibbs energy of sorption of the solid-liquid interface were determined for montmorillonite, three types of soil, and their humin fractions. The soils were found to be less polar or less hydrophilic than the clay, and the humin fraction of soils was found to be less hydrophilic than the whole soils. The soil and humin samples have heterogeneous surfaces which can be divided in two regions on the basis of their relative polarity. The x-axis intersection of the straight section of isotherm assigns the relative proportions of the hydrophilic and hydrophobic regions of the surface.

The properties of the adsorption layer and the stability of aerosil dispersions in binary liquids

From a knowledge of the adsorption, immersion and wetting properties, we have examined the influence of particle—particle and particle—liquid interactions on the stability and structure formation of suspensions of hydrophobic and hydrophilic aerosil particles in the mixtures benzene— n-heptane, methanol—benzene and 1-propanol—water. For the binary mixtures, the Hamaker constants have been determined by optical dispersion measurements over the entire composition range. The Hamaker constant of the adsorption layer, of composition different from that in the bulk, has been calculated for several mixture compositions on the basis of the above results. Having the excess isotherms available enabled us to determine the adsorption layer thickness as a function of the mixture composition. For interparticle attractive potentials, model calculations have been effected on the basis of the Vincent model. In the case of hydrophobic particles dispersed in benzene— n-heptane and methanol—benzene mixtures, it was established that the change in the attractive potential was in accordance with the interactions obtained from rheological measurements. However, for silica particles dispersed in 1-propanol—water mixtures, the structure-forming and rheological properties of the dispersed system are determined by the alcohol—water structure, i.e. by propanol—water clusters.

Reaction of 2,6-dinitroanisole with cyclohexylamine in toluene–octanol binary solvents. Further support for the ‘dimer nucleophile mechanism’ in aromatic nucleophilic substitution

The reaction of 2, 6-dinitroanisole with cyclohexylamine in toluene, octanol and toluene–octanol mixtures has been studied at several amine concentrations. The reactions in toluene and in octanol–toluene mixtures up to 30% octanol show a third-order kinetic dependence on [amine]. Although the reaction rates in toluene and octanol are very similar, addition of small amounts of octanol to the toluene solution diminishes the rate of reaction, reaching a minimum value at 30–50% octanol, after which the rate increases almost linearly with the octanol content. These and other results, here described, are satisfactorily explained by the previously proposed ‘dimer nucleophile mechanism’. Previously reported similar observations in methanol–benzene mixtures were criticised as being due to the reversibility of the reaction. The present results confirm the previously reported mechanism and the irreversibility of the reaction under the reaction conditions.

Rheological, adsorption and stability behaviour of hydrophobic aerosil particles in binary liquid mixtures

Rheological and optical properties of hydrophobic aerosil particles were examined in benzene— n-heptane and methanol—benzene mixtures. Adsorption measurements on these mixtures proved that the composition of the adsorption layer is a crucial factor determining the adhesion between the particles. The Bingham yield stress and the Ree—Eyring parameters (from rheological measurements) are influenced significantly by the composition of the interfacial layer calculated from adsorption measurements in binary liquids. The minimum of the free energy function for the interfacial layer determines the stability of the particles dispersed in binary mixtures.

Liquid sorption and wetting oil hydrophilic/hydrophobic layer silicates

Adsorption excess isotherms were determined on hydrophobic layer silicates in methanol-benzene mixtures. From these isotherms the displacement free energy Δ 21 G= f ( x 1) is derived which is characteristic of surface polarity. Displacement enthalpy isotherms were also determined by immersion microcalorimetry so that the entropy changes could be calculated. The molar displacement energy and adsorption capacity are calculated by a combination of enthalpy and free energy isotherms with adsorption excess isotherms.

Surface modification and surface thermodynamic potential functions at the s/l interface

The adsorption of methanol-benzene mixtures was studied on adsorbents of different polarity. Besides adsorption measurements, the displacement enthalpy isotherms were determined by flow microcalorimetry. The adsorption exchange process was modelled with calculations utilizing bulk phase activity data, for adsorbents of different polarity. The results provide further possibilities for calculating the surface excess free energy, enthalpy and entropy functions. With respect to adsorption capacity and molar adsorption enthalpy determination, a new equation is proposed.

Micellization and Conductance Behaviour of Thorium Soap Solutions

Abstract The critical micelle concentration, degree of dissociation and dissociation constant of dilute solutions of thorium soaps in methanol-benzene mixtures were determined from conductivity measurements. The results showed that these soaps behave as weak electrolytes in dilute solutions below the CMC and the CMC increases in presence of Sudan (IV) dye. The various thermodynamic parameters were also evaluated for both dissociation and micellization processes.

Wetting and adsorption on organophilic illites and swelling montmorillonites in methanol-benzene mixtures

Adsorption and immersion were studied simultaneously in methanol-benzene mixtures on non-swelling organophilic illites and swelling organophilic montmorillonites. From the combination of adsroption and calorimetric data, equations were proposed for the determination of the adsorption capacity and the molar enthalpies of wetting differences, if the adsorption layer behaved ideally. From the experimental enthalpy isotherms of wetting and the enthalpy functions related to the ideal behaviour of the layer, qualitative conclusions were drawn on the excess enthalpy of the adsorpition layer. It was again established that the adsorption layer composed of alkyl chains, benzene and methanol has a regular cluster structure in certain concentration ranges, which breaks at higher methanol concentrations. This change is reflected by a significant endothermic peak of the differential molar enthalpy. For the organophilic montmorillonites, the enthalpy of swelling was determined separately as a function of the composition. The non-swelling organophilic illites were chosen as a reference system.

Enthalpy of displacement of binary liquid mixtures on solid surfaces part II. Analysis of S-shaped excess isotherms

The adsorption and enthalpy of displacement in methanol—benzene mixtures have been studied on adsorbents with different surface polarities: hydrophobic silica, activated carbon and graphitized carbon black. An investigation of systems producing S-shaped excess isotherms was conducted to determine which function transformations can be used to transform the integral enthalpy of displacement isotherms into the function ψ s 1 = f (ø 1), the shape of which corresponds to the function ø s 1 = f (ø 1) calculated from the excess isotherms. It has been established that, in the event of ideal behaviour of the adsorption layer (Δ H se = 0), the composition of the interfacial layer (ø s 1) is identical to the displacement factor (ψ s 1), i.e. the composition of the surface layer can be determined merely from calorimetric data. The excess enthalpy of the adsorption layer (Δ H se≠ 0) on the surface of the graphitized carbon black adsorbent with a homogeneous surface energy distribution agrees to a good approximation with that of the bulk phase measured experimentally.

Sorption and immersional wetting on clay minerals having modified surface: II. Interlamellar sorption and wetting on organic montmorillonites

Adsorption of methanol-benzene mixtures and heats of immersion have been investigated on the organic derivatives of montmorillonite. The surface of the mineral was modified by n-alkyl pyridinium and dimethyldihexadecyl ammonium ions. In the case of completely exchanged samples the adsorption capacity volumes agree with the interlamellar volumes calculated from X-ray diffraction data rather well. The organophilicity is characterized by the proportion of the nonpolar/polar surfaces. The specific enthalpies of immersion have been measured in methanol, benzene, and their mixtures. The immersion shows endothermic-exothermic or endothermic heat effects.

Sorption and immersional wetting on clay minerals having modified surface. I. Surface properties of nonswelling clay mineral organocomplexes

Adsorption of methanol-benzene mixtures and the immersional wetting properties have been investigated on nonswelling clay minerals with lamellar structure (kaolinite and illite) and on their organocomplexes obtained by hexadecyl-pyridinium cations (HDP +). It has been found that the surface modification can influence the selective liquid adsorption. To interpret unambiguously the extent of the surface modification the nonpolar-polar surface area ratio can be calculated from the sorption data. From the excess isotherms and the enthalpy of immersion the surface thermodynamic potential functions have been calculated. The changes of these functions and the equilibrium constant of the adsorption with the surface polarity is given. Adsorption capacity data and immersional wetting experiments indicate that the surface extension of these organocomplexes can change in some degree.

Effect of surface modification on solid-liquid interfacial adsorption of mixtures

A study was made on the adsorption of methanol-benzene mixtures on organophilic montmorillonites with surfaces modified to various extents. The effect of the extent of surface modification on the shapes of the excess isotherms was established. A model isotherm equation was given taking into account, among others, the polar-apolar surface area ratio of the adsorbent.

Reactions of hot hydrogen atoms in irradiated C 6H 6C 6H 12 and C 6H 6CH 3OH mixtures

The data on recoil tritium atoms reactions in cyclohexane-benzene and methanol-benzene mixtures are used to estimate the hot H atom contribution to H 2 and low molecular weight hydrocarbon formation during the radiolysis of the same systems. The total H 2 yield from irradiated cyclohexane-benzene mixtures is interpreted in terms of abstraction by hot and thermal H atoms and “molecular” H 2 detachment from the cyclohexane molecule, this suggests that benzene does not affect the formation and decomposition of excited C 6H 12 species giving rise to hot H atoms, but easily scavenges precursors of “molecular” H 2.

Solubility of cadmium laurate using radioactive 115mCadmium as a tracer

The solubility of cadmium laurate in water, many nonaqueous solvents, and aqueous solutions of Manoxol OT has been determined by using 115mCd as a tracer and in methanol-benzene mixtures by an evaporation method. The cadmium soap has been found to be spare both in water and in many nonaqueous solvents. However, its solubility in alcohols is relatively much higher, owing to solute-solvent interaction. The c.m.c. values of cadmium laurate in benzene, toluene, and m-xylene have been calculated from the solubility data at different temperatures and found to be 3.8 × 10 −5 M, 9.0 × 10 −5 M, and 9.8 × 10 −5 M, respectively. Solubility data have also been used to calculate the c.m.c. of Manoxol OT in aqueous solution. Small amounts of methanol in benzene enhance the solubility of cadmium soap in the latter solvent tremendously.

Thermodynamic properties of methanol–benzene mixtures at elevated temperatures

AbstractThe total pressure and the compositions of the vapour and liquid phases of the methanol–benzene system have been determined under equilibrium conditions at 100°, 120°, 140°, 160°, 180°, 200° and 220° for ten levels of concentration. The corresponding activity coefficients of methanol and benzene are reported; their values indicate that the equilibrium data are thermodynamically consistent.An azeotrope is found at all temperatures, its methanol content increasing as the temperature is increased. The relationship log Paz = 6·5098—(1,766/T) expresses the interdependence of the azeotrope vapour pressure Paz(lb/in2 abs.) and temperature T(°K).Estimates of integral heat of mixing (HE) and entropy change due to mixing (SE) as functions of liquid composition (xmeth) have been made from the excess free energy of mixing GE,(T) xmeth functions. Both HE and SE at a given x are positive increasing functions of temperature. These phenomena are discussed in terms of the dissociation of methanol ‘polymer’ and the formation of benzene–methanol ‘complexes’.

Radical Scavenging in the Radiolysis of Liquid Methanol-Benzene Mixtures

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRadical Scavenging in the Radiolysis of Liquid Methanol-Benzene MixturesA. Ekstrom and J. L. GarnettCite this: J. Am. Chem. Soc. 1964, 86, 22, 5028–5030Publication Date (Print):November 1, 1964Publication History Published online1 May 2002Published inissue 1 November 1964https://doi.org/10.1021/ja01076a075RIGHTS & PERMISSIONSArticle Views24Altmetric-Citations8LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (357 KB) Get e-Alerts Get e-Alerts

Electrolyte—Solvent Interaction. II. Quaternary Salts in Methanol—Nitromethane and Methanol—Benzene Mixtures

Electrolyte—Solvent Interaction. II. Quaternary Salts in Methanol—Nitromethane and Methanol—Benzene Mixtures