Water Organic Liquid Research Articles

POLYELECTROLYTE COMPLEX NANOPARTICLES OF SOLUBLE LIGNIN AND CHITOSAN AS INTERFACIAL MODIFIER

A water-soluble non-stoichiometric polyelectrolyte complex (LCP) was obtained as a result of the interaction of oppositely charged kraft lignin and high molecular chitosan by mixing their dilute water solutions. The sizes of the LCP nanoparticles were characterized by a bimodal distribution at pH 6, and their values were essentially smaller than the sizes of the chitosan particles. It was found that the LCP nanoparticles were characterized by remarkably lower values of surface tension at the air-water and the water-organic liquid interface in comparison with the initial biopolymers. With decreasing pH and increasing concentration of the LCP nanoparticles in the water solution, their adsorption ability at the interfaces was enhanced. The interface tension at the water-heptane interface changed non-linearly with increasing the polyelectrolyte complex concentration that was associated with the “saturation” effect. The dependence of the ability of the LPC nanoparticles to stabilize oil-in-water emulsion on pH values of the water phase was found.

A new molecular thermodynamic model of liquid-liquid interfacial tension

• A new molecular thermodynamic model of interfacial tension is derived. • This model yields satisfactory prediction results for interfacial tension. • It doesn't require mutual solubility data for interfacial tension predictions. • This model is simple in implementation and reliable in application. Interfacial tension between water and organic liquids plays an important role in the design and optimization of various processes, such as enhanced oil recovery, the entrapment and migration of non-aqueous phase liquid (NAPL), chemical separation technology (liquid-liquid extraction) relevant to ex-situ hazardous waste remediation and chemical processing. A new molecular thermodynamic approach of monolayer interface model was developed in this work, in which the total interfacial energy includes contributions from the excess interface cohesive energy and excess interface entropy (entropy from partially mixing and entropy from free volume change). The accuracy of this model in the prediction of interfacial tension for water-organic liquid and mercury-nonmetallic liquid systems has been examined with satisfactory results. The investigation results indicates that for water-organic liquid systems, the excess interface entropy term makes considerable contribution (9.5%∼46.6%) to the total interfacial energy, which may result in the interaction parameter of Girifalco and Good model being greater than unity (1.04≤ Φ ≤1.15) for water-alcohols; while for mercury-nonmetallic liquid systems, the contribution to the total interfacial energy from interfacial entropy is negligible (1.2%∼2.7%), the difference in cohesive energy of molecules between the bulk phase and interfacial phase dominates the wetting process. This method doesn't require measured mutual solubility data for interfacial tension predictions, which is simple in implementation and reliable in application.

Nucleation of gas hydrates in multiphase systems with several types of interfaces

Isothermal nucleation of gas hydrates in two-layer water–organic liquid systems was studied with the use of Sapphire Rocking Cell RCS6 with six transparent sapphire cells by thermal analysis under gas pressure. The experiments were conducted at constant supercooling (about 20.2 °C). Decane (both with and without surfactants Surfynol 420 and Span 80) and crude oils were used as organic liquids. It was observed that gas hydrate nucleation occurred at water–stainless steel–gas and water–sapphire–organic liquid three-phase contact lines rather than at water–gas or water–organic liquid interfaces. The empirical survival curves were constructed for the entire set of data. Two series of experiments for the system of water–decane–Surfynol 420–methane with the same sample were also conducted. The series of experiments differed with cell angle relative to the horizontal (45° and 14°). Comparison of the observed thermal effects with data of visual examination for this system allowed nucleation rates of methane hydrate on the different nucleation sites to be determined.

Effect of pluronic P123 on the distribution of nanodiamond particles in water–organic liquid systems

The effect adsorption layers of nonionic surfactant (pluronic P123) have on the distribution of nanodiamonds (NDs) between aqueous and organic phases is studied with radioactive tracers using compounds labeled with tritium. The values of reversible and irreversible adsorptions of P123 on NDs are determined. It is shown that the distribution coefficients of NDs modified by irreversibly adsorbed layers of P123 are several times higher than those of raw nanodiamonds. This result is explained by the hydrophobization of an ND’s surface, as is shown by data obtained via interfacial tensiometry and wetting.

Characterizing Pore-Scale Dissolution of Organic Immiscible Liquid in Natural Porous Media Using Synchrotron X-ray Microtomography

The objective of this study was to characterize the pore-scale dissolution of organic immiscible-liquid blobs residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of the aqueous, organic-liquid, and solid phases residing in columns packed with one of two porous media. Images of the packed columns were obtained after a stable, discontinuous distribution (e.g., residual saturation) of the organic liquid (trichloroethene) had been established, and three subsequent times during column flushing. These data were used to characterize the morphology of the organic-liquid blobs as a function of dissolution, and to quantify changes in total organic-liquid volume, surface area, and water-organic liquid interfacial area. The dissolution dynamics of individual blobs appeared to be influenced by the local pore configuration. In addition to dissolution-induced shrinkage, some blobs were observed to separate into multiple distinct subunits. The median blob size decreased by approximately a factor of 2 at the point where approximately 90% of the initial organic-liquid volume had been removed. The ratio of capillary associated interfacial area to total water-organic liquid interfacial area increased by 50% at the point where approximately 95% of the initial mass had been removed. A nearly linear relationship was observed between both total and capillary associated interfacial area and organic liquid volumetric fraction. Changes in the measured aqueous-phase trichloroethene effluent concentrations were well correlated with changes in the volume, surface area, and number of blobs. The effluent concentration data were adequately described by a first-order mass transfer expression employing a constant value of the mass-transfer coefficient, with values for the water-organic liquid interfacial area obtained independently from the microtomography data.

Characterizing Pore‐Scale Configuration of Organic Immiscible Liquid in Multiphase Systems With Synchrotron X‐Ray Microtomography

The objective of this study was to examine the pore‐scale distribution and morphology of organic immiscible liquid in natural porous media containing three immiscible fluids. High‐resolution, three‐dimensional images of an organic liquid (tetrachloroethene) in both three‐phase (water–air–organic liquid) and two‐phase (water–organic liquid) systems were obtained using synchrotron X‐ray microtomography. These data were used to quantitatively characterize the morphology of the organic liquid residing within columns packed with one of three natural, sandy porous media. Organic‐liquid blobs varied greatly in both size and shape, ranging from small, single spheres (≥0.03 mm in diameter) to large, amorphous ganglia with mean lengths of 4 to 5 mm. Singlets comprised the greatest number of blobs, whereas the large ganglia, while much fewer in number, comprised the majority of the organic‐liquid surface area and volume. A significant portion of the organic liquid in the three‐phase systems was observed to exist as lenses and films in contact with air. These features were not observed in the two‐phase water–organic liquid systems. The median of the blob‐frequency distributions was smaller and the variance larger for the three‐phase systems. In addition, the global specific surface areas of the organic liquid were greater for the three‐phase systems. These differences are attributed to the presence of the organic‐liquid lenses and films for the three‐phase systems.

Thermal Resistance of Nanoscopic Liquid−Liquid Interfaces: Dependence on Chemistry and Molecular Architecture

Systems with nanoscopic features contain a high density of interfaces. Thermal transport in such systems can be governed by the resistance to heat transfer, the Kapitza resistance (RK), at the interface. Although soft interfaces, such as those between immiscible liquids or between a biomolecule and solvent, are ubiquitous, few studies of thermal transport at such interfaces have been reported. Here we characterize the interfacial conductance, 1/RK, of soft interfaces as a function of molecular architecture, chemistry, and the strength of cross-interfacial intermolecular interactions through detailed molecular dynamics simulations. The conductance of various interfaces studied here, for example, water-organic liquid, water-surfactant, surfactant-organic liquid, is relatively high (in the range of 65-370 MW/m2 K) compared to that for solid-liquid interfaces ( approximately 10 MW/m2 K). Interestingly, the dependence of interfacial conductance on the chemistry and molecular architecture cannot be explained solely in terms of either bulk property mismatch or the strength of intermolecular attraction between the two phases. The observed trends can be attributed to a combination of strong cross-interface intermolecular interactions and good thermal coupling via soft vibration modes present at liquid-liquid interfaces.

Determining the Gibbs Energy of Ion Transfer Across Water–Organic Liquid Interfaces with Three‐Phase Electrodes

Ions can be transferred between immiscible liquid phases across a common interface, with the help of a three-electrode potentiostat, when one phase is an organic droplet attached to a solid electrode and containing a redox probe. This novel approach has been used in studies to determine the Gibbs energy of anion and cation transfer, ranging from simple inorganic and organic ions to the ionic forms of drugs and small peptides. This method of studying ion transfer has the following advantages: (1) no base electrolytes are necessary in the organic phase; (2) the aqueous phase contains only the salt to be studied; (3) a three-electrode potentiostat is used; (4) organic solvents such as n-octanol and chiral liquids such as D- and L-2-octanol can be used; (5) the range of accessible Gibbs energies of transfer is wider than in the classic 4-electrode experiments; (6) the volume of the organic phase can be very small, for example, 1 microL or less; (7) the experiments can be performed routinely and fast. Herein, the basic 5 principle is outlined, as well as a summary of the results obtained to date, and a discussion on the theoretical treatments concerning the kinetic regime of the three-phase electrodes with immobilized droplets.

An improved estimation of water–organic liquid interfacial tension based on linear solvation energy relationship approach

An equation based on the linear solvation energy relationship (LSER) was proposed to predict the interfacial tension between organic liquid and water. The equation takes into account five parameters characterizing properties of the organic liquid molecule: excess molar refraction, solute dipolarity/polarizability, effective hydrogen bond acidity, effective hydrogen bond basicity, and the McGowan molar intrinsic volume. The proposed equation provides a better approximation of the interfacial tension than a similar one derived earlier by Freitas et al. (J. Phys. Chem. B 101 (1997, 7488-7493), which is based on seven terms.

DISTRIBUTION OF METHYL RED ON THE WATER–ORGANIC LIQUID INTERFACE IN A MICROCHANNEL

Molecular transport across a water–organic liquid interface formed parallel to the side wall of a microchannel on microchips has been studied using methyl red as model compound and cyclohexane and n-octanol as organic solvents. The molecular transport was monitored by thermal lens microscopy and the kinetics of the process was studied for different concentrations and flow velocities. The influence of physico–chemical interactions between the model compound and organicso lvents on liquid–liquid interface was demonstrated in the microspace and corresponding partition coefficients were calculated which confirmed the experimental results.

Structure formation and interaction of silanized glass beads at water-fluid interfaces: a redispersability study

Abstract The aggregation and spreading of silanized glass microspheres (diameter: 62–74 μm) were investigated at water (electrolyte)-fluid interfaces by evaporating hexane or chloroform from the water surface. Redispersion of aggregates was attributed to non-equilibrium interfacial tension at the water-fluid interface in the final stage of evaporation. The effect of particle wettability on this phenomenon was studied. Two different hydrophobic samples (Sample A: Θwater/air=77 ± 1°; Sample B: Θwater/air=44 ±1°) were prepared for experiments. Two-liquid wettability of particles was also characterized by contact angles (Sample A: Θ water hexane = 100 ± 4 °; Sample B: Θ water hexane = 57 ± 3 °) by means of which the colloid and capillary pair-potential energies have been calculated. In every case the aggregation yielded well-packed aggregates at the water-organic liquid interface, but spreading experiments showed that while the aggregate of the lower hydrophobic sample could disperse into little clusters or single particles, the higher hydrophobic particles remained together in the final stage of organic liquid evaporation. The speed and extent of redispersion of the lower hydrophobic sample were found to be dependent on the spreading liquids (hexane or chloroform), but the electrolyte (KCl) content of the subphase could not influence the process. The aggregates of higher hydrophobic particles could be redispersed in neither case investigated. It was proposed, on the basis of the calculated interparticle energies, that the higher hydrophobic particles could come into direct contact during the organic liquid evaporation due to the strong “immersion-type” capillary and hydrophobic attractive interactions. We characterized the dispersing ability of the spreading liquids used by a parameter (“dispersing energy”: 25.1 mN m−1 for hexane; 46.8 mN m−1 for chloroform) which could be calculated from a supposed interfacial tension difference at the water-air interface arising during the final stage of organic liquid evaporation. These values were compared with the “pull-off energy” (≈90 mN m−1) obtained earlier for silanized glass surfaces [J.L. Parker and P.M. Claesson, Langmuir, 10 (1994) 635]. The results confirmed the above suggestion that hydrophobic spheres (Sample A) can reach a situation in which the strong adhesion between them can hinder their redispersion and, furthermore, made it reasonable to assume that the aggregates of lower hydrophobic particles (Sample B) could be redispersed better if chloroform was used as spreading liquid.

Study on condensation heat transfer of binary of immiscible liquids. Experimental study.

In order to clarify the condensation heat transfer mechanism of binary vapors of immiscible liquids, detailed experiments have been conducted with regard to the condensation of an azeotropic mixture of carbon tetrachloride and water on a vertical flat plate. The experimental results indicate that the condensation heat transfer coefficient of the mixture is larger than that of the pure organic vapor, and its mechanism can be explained to be in relation with the dynamic behavior of mixed condensate consisting of water droplets and organic liquid film flow.

Thin oriented films of molybdenum disulphide

Single molecular layers of molybdenum disulphide in suspension in water can be collected at a water-organic liquid interface if mixed well with an immiscible organic liquid. Techniques are described for depositing thin (30–350A˚), highly oriented optical quality films of restacked MoS2 on a variety of substrates. Characterization of the MoS2 films with X-ray diffraction and optical absorption are described. The same techniques are successfully applied in depositing oriented films of unexfoliated MoS2 and WS2 powder.

Surface free-energy components of liquids and low energy solids and contact angles

Employing the values of organic liquid surface tension and interfacial surface tension of water-organic liquid, values of dispersion and nondispersion components of these liquids were calculated and compared with those obtained in another way. For these organic liquids and water, the values of the contact angle on paraffin wax, polytetrafluoroethylene, polyethylene, polyethylene terephthalate, and polymethyl methacrylate were measured. The values of dispersion and nondispersion components of surface free energy of these polymers and paraffin wax were calculated using the measured values of the contact angle for diiodomethane and water and the calculated values of the components of their surface tension. These calculated data were in agreement with the literature data. Taking our values of free energy components of liquids and solids, the values of the contact angle for these solids were calculated and compared with those measured, obtaining good agreement. On the basis of the measurements and calculations it was found that dispersion and nondispersion components of surface free energy of liquids and solids “work well” in the systems studied.

Correlation of liquid-liquid equilibria for some water-organic liquid systems in the region 20-250.degree.C

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCorrelation of liquid-liquid equilibria for some water-organic liquid systems in the region 20-250.degree.CHerbert H. Hooper, Stefan Michel, and John M. PrausnitzCite this: Ind. Eng. Chem. Res. 1988, 27, 11, 2182–2187Publication Date (Print):November 1, 1988Publication History Published online1 May 2002Published inissue 1 November 1988https://doi.org/10.1021/ie00083a039RIGHTS & PERMISSIONSArticle Views547Altmetric-Citations36LEARN 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 (625 KB) Get e-Alerts Get e-Alerts

Interaction at interfaces and induction of surface free energy components

A set of published data on surface free energy (γ1, γ2) and interfacial energy (γ12) for interfaces mercury-organic liquid, mercury-water, and water-organic liquid (125 pairs altogether) has been critically evaluated. It has been found that the Antonow rule does not hold, that the Neumann equation is suitable for determining the work of adhesion, if γ1 and γ2 are not too different, and that the Fowkes equation can be used to assess the type of interaction at the interface. A hypothesis has been suggested which states that, besides the interaction between dispersion components of the surface free energies of the adjoining phases and the interaction between the non-dispersion components of the same type in bulk, a non-dispersion component of one phase may interact by inducing a component of the same type in the other phase near the interface. Relations concerning the mechanism of interaction at the interface have been derived. Also, the relation between the Girifalco-Good, Neumann and complemented Fowkes equation has been evaluated. For the particular liquids the dispersion portion of their surface free energies and the interaction mechanism at their interface with water and mercury have been estimated. For water, e.g. the polar component of the surface free energy (14.7 mJ m-2) and the hydrogen-bond component (36.3 mJ m-2) have been determined. The introduction of the induced component of the surface free energy is shown, as an example, for water-aromatic hydrocarbons and water-alcohols systems.

Wetting, swelling and sediment volumes of organophilic clays

Sediment volumes and basal spacings of hydrophilic and organophilic montmorillonites were measured in parallel with adsorption isotherms and immersion enthalpies of these clays. The sediment volumes of hydrophilic montmorillonites in apolar media grow parallel with the amount of adsorbed water and with the water—organic liquid interfacial tension. From excess isotherms of benzene—alcohol mixtures on organophilic clays, the adsorption capacities for the apolar and polar components are given separately. By measuring the basal spacings, the distribution of the interlamellar liquid between the adsorption and the swelling phases is calculated. The total heat of immersion measured by microcalorimetric method is composed of exothermic wetting and endothermic swelling heats. For swelling, work should be directed against the forces acting between the layers, and entropy changes play a decisive role. Sediment volumes of organophilic montmorillonites change with adsorption and swelling in a complex manner.

Surface activity of some merocyanines and spiropyrans at liquid-liquid interfaces

Abstract Interfacial tension lowerings at water-organic liquid interfaces have been measured for some merocyanines and spiropyrans by the pendant drop method. Merocyanine dyes are found to be surface active at the water-organic liquid interface. Colored species of the photochromic spiropyrans are also surface active at the water-organic liquid interface, whereas the colorless forms are not. The surface activity of the colored species of spiropyrans is similar to that of analogous merocyanine dyes. The interfacial tensions of water and organic liquid systems which contain photochromic spiropyrans can be decreased by irradiation with ultraviolet radiation and can subsequently be increased by removal of the ultraviolet radiation. The extent of the interfacial tension lowerings by the spiropyrans is largely dependent upon the degree of solubility and concentration of the dye in the organic liquid.

The Boundary Tension at Water-Organic Liquid Interfaces

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Boundary Tension at Water-Organic Liquid InterfacesD. Joseph Donahue and F. E. BartellCite this: J. Phys. Chem. 1952, 56, 4, 480–484Publication Date (Print):April 1, 1952Publication History Published online1 May 2002Published inissue 1 April 1952https://doi.org/10.1021/j150496a016RIGHTS & PERMISSIONSArticle Views1582Altmetric-Citations250LEARN 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 (623 KB) Get e-Alerts

Adsorption at Water–Air and Water–Organic Liquid Interfaces.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdsorption at Water–Air and Water–Organic Liquid Interfaces.F. E. Bartell and James K. DavisCite this: J. Phys. Chem. 1941, 45, 8, 1321–1336Publication Date (Print):August 1, 1941Publication History Published online1 May 2002Published inissue 1 August 1941https://doi.org/10.1021/j150413a019RIGHTS & PERMISSIONSArticle Views98Altmetric-Citations30LEARN 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 (734 KB) Get e-Alerts