Showing papers on "Activity coefficient published in 2018"
24 Apr 2018
TL;DR: In this paper, the Gibbs Phase Rule is used to describe the Gibbs phase of the Debye-Huckel law for the activity coefficients of Aqueous Ions.
Abstract: PART 1: INTRODUCTION. Overview. Thermodynamic Principles. PART 2: ACID/BASE CHEMISTRY. [H+] as an Important and Meaningful Thermodynamic Variable in Aquatic Chemistry. The Proton Balance, Electroneutrality, and Mass Balance Equations. Introduction to Quantitative Equilibrium Calculations. pH as a Master Variable. Titrations of Acids and Bases. Buffer Intensity b, and the Effects of Changes in b With pH on Titration Curves. Chemistry of Dissolved CO2. Gran Titrations. PART 3: MINERAL/SOLUTION CHEMISTRY. Solubility Behaviors of Simple Mineral Salts, and Metal Oxides, Hydroxides, and Oxyhydroxides. Solubility Behavior of Metal Carbonates in Closed Systems. Solubility of Metal Carbonates in Open Systems With a Gas Phase of Constant pCO2. Solubility Control, Solubility Limitation, the Coexistence of Multiple Solid Phases, and Multiple-Solid Predominance Diagrams. Solubility as a Function of Particle Size. Solid/Solid and Liquid/Liquid Solution Mixtures. The Gibbs Phase Rule. PART 4: METAL/LIGAND CHEMISTRY. Complexation of Metal Ions by Ligands. PART 5: REDOX CHEMISTRY. Redox Reactions pe, and EH. Introduction to pe-pH Diagrams: The Cases of Aqueous Chlorine, Hydrogen, and Oxygen. pe-pH Diagrams for Aqueous Lead in the Absence of CO2. pe-pH Diagram for Aqueous Lead in the Presence of CO2 With Fixed CT. pe and Natural Systems. The pe Changes in a Stratified Lake During a Period of Summer Stagnation: An Example of a Redox Titration. PART 6: EFFECTS OF ELECTRICAL CHARGES ON SOLUTION CHEMISTRY. The Debye-Huckel Law and Related Equations for the Activity Coefficients of Aqueous Ions. Electrical Double Layers in the Aqueous System. Stability and Coagulation of Colloidal Suspensions. INDEX.
226 citations
207 citations
TL;DR: In this article, the interaction of anionic bile salt sodium taurocholate (NaTaC) and anionic anti-inflammatory drug sodium salt of ibuprofen (NaIBU) in aqueous solutions together with in occurrence of 100mmol kg−1 NaCl and 250mmolkg−1 urea (NH2CONH2) using tensiometric and fluorometric techniques at 298.15
149 citations
TL;DR: In this article, the adjustable parameters in the popular conductor-like screening model for real solvents (COSMO-RS) within the Amsterdam density functional (ADF) framework have been re-optimized to fit for the systems containing ionic liquids (ILs).
90 citations
TL;DR: In this article, sixty imidazolium-based ionic liquids were screened by using the COSMO-SAC model based on the evaluation of the selectivity, capacity and performance index, which were derived from the activity coefficient at infinite dilution.
82 citations
TL;DR: In this paper, the aqueous solubility of acetaminophen (ACP) in some choline chloride (ChCl) based deep eutectic solvents (DESs) with urea, oxalic acid and malonic acid as neoteric green solVents were measured up to 0.90
76 citations
70 citations
TL;DR: In this article, the importance of the dielectric constant is critically reviewed, with a focus on the use of a salt-concentration dependent function using an equation of state (EoS).
70 citations
TL;DR: In this paper, an accurate, consistent and reliable hydrogen solubility model is established, which allows to calculate the hydrogen insolubility in the formation fluid and the corresponding variation of fluid density.
62 citations
TL;DR: In this paper, the SAFT-VR Mie equation of state (EoS) is extended to solutions of salts which are assumed to be strongly dissociating in water, through the addition of a Born term for accurate representation of the Gibbs energy of solvation, and a Debye-Huckel term for long-range, electrostatic interactions.
TL;DR: In this article, the effect of the addition of nonionic surfactants with a longer or shorter hydrophilic chain, e.g., OP-10 or OP-4, on the micellization of the binary mixture of C12AS/OP-7 with a maximum synergism was investigated using both the tensiometry and the 1H NMR technique.
TL;DR: In this paper, the authors reported new data on the vapour pressure of ammonia with ionic liquid mixtures with 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate [EtOHmim][BF4].
TL;DR: The experimental results showed that the mole fraction solubility of cyromazine in sixteen pure solvents decreased according to the following order: acrylic acid, polypropanoic acid, acrylic acid and acrylic acid as discussed by the authors.
TL;DR: In this paper, the authors investigated the aggregation behavior of binary IL surfactant micelles composed of the ILs choline oleate ([Cho][Ol]) and choline laurate (Cho][Lau]) in aqueous media using tensiometry and dynamic light scattering measurements.
TL;DR: In this article, a type III DES based on ammonium salt was investigated as an alternative solvent to currently employed conventional organic solvents in separation processes, and the effect of the structure of the solutes on γ 13 ∞ was also investigated.
TL;DR: In this paper, a thermodynamic model to predict three phase equilibria of gas hydrates is presented, where the hydrate phase is modeled using van der Waals-Platteeuw solid solution theory and the liquid phase activity coefficients are determined from the modified UNIFAC method.
TL;DR: In this paper, the authors developed a multi-temperature thermodynamically consistent model for salt lake brine systems using the Pitzer-Simonson-Clegg (PSC) model.
Abstract: This paper is part of a series of studies on the development of a multi-temperature thermodynamically consistent model for salt lake brine systems. Under the comprehensive thermodynamic framework proposed in our previous study, the thermodynamic and phase equilibria properties of the sulfate binary systems (i.e., Li2SO4 + H2O, Na2SO4 + H2O, K2SO4 + H2O, MgSO4 + H2O and CaSO4 + H2O) were simulated using the Pitzer-Simonson-Clegg (PSC) model. Various type of thermodynamic properties (i.e., water activity, osmotic coefficient, mean ionic activity coefficient, enthalpy of dilution and solution, relative apparent molar enthalpy, heat capacity of aqueous phase and solid phases) were collected and fitted to the model equations. The thermodynamic properties of these systems can be well reproduced or predicted using the obtained model parameters. Comparisons with the experimental or model values in literature indicate that the model parameters determined in this study can describe all of the thermodynamic and phase equilibria properties of these binary sulfate systems from infinite dilution to saturation and freezing point temperature to approx. 500 K.
TL;DR: The liquid-liquid equilibrium (LLE) data for the three ternary systems, methyl butyl ketone (MBK), m-, m-, p-cresol, and water, were measured at 3332 k and 3532 k under 101 kPa in this paper.
TL;DR: In this article, the authors used stochastic retention data acquired by gas-liquid chromatography to determine the activity coefficients at infinite dilution for 24 organic solutes in the deep eutectic solvent (DES) consisting of tetramethylammonium chloride and glycerol in a molar ratio of 1.001:2.
TL;DR: In this paper, the authors measured the solubility of indomethacin (IMC) in water, and the results indicated that the IMC is increased by increasing the concentration of [EMIM][ES] and temperature.
TL;DR: In this paper, the ternary system ethanol+hexane+2,5 -dimethylfuran was measured in a vapor-liquid equilibrium still with circulation of both phases and the dependence of interfacial tensions on concentration was also determined at atmospheric pressure and 298.15
TL;DR: The formation of MEF‐ionic liquid compounds greatly increases the solubility in water in comparison with pure MEF or complexes with 2‐hydroxypropyl‐&bgr;‐cyclodextrin, which will assist in medication taking into account oral solid or gel medicines.
TL;DR: In this paper, a comprehensive treatment of the binary system ZnSO4-H2O including solution properties and phase equilibria involving various hydrates of zinc sulfate is presented.
TL;DR: In this article, liquid-liquid equilibrium data (LLE) were obtained for aqueous two-phase systems (ATPS) composed of polyethylene glycol (average molar mass of 1500g/mol−1), sodium citrate/citric acid and water, at different pH (4.0, 5.0 and 6.0) and temperatures T = (303.15 and 313.15) K. The experimental results of the LLE were correlated using the UNIversal Functional Activity Coefficient (UNIFAC) model.
TL;DR: In this article, the COSMO-RS approach was used to qualitatively and quantitatively screen five choline chloride-based deep eutectic solvents (DESs) to separate the azeotropic binary formed between benzene and either methanol or ethanol.
Abstract: In this study, the COSMO-RS approach was used to qualitatively and quantitatively screen five choline chloride-based deep eutectic solvents (DESs) to separate the azeotropic binary formed between benzene and either methanol or ethanol The activity coefficient at infinite dilution was calculated to evaluate the capacity, selectivity, and performance index of each DES The interactions between the different species were also analyzed by interpreting the σ-profile and σ-potential of each component Then, three DESs were selected for experimental validation They were prepared by combining choline chloride with ethylene glycol, levulinic acid, and 1,2-propanediol The best performance in terms of distribution ratio and selectivity was achieved with choline chloride/ethylene glycol DES with 1:4 molar ratio The experimental tie-lines were successfully correlated using the NRTL model Regardless of the system investigated, no DES was found in the raffinate phase, implying minimal cross-contamination Finally,
TL;DR: In this article, the effect of interactions between organic solvents and water on the interfacial and bulk properties of N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA] were discussed on the base of the limiting activity coefficients γ 13 ∞ values.
TL;DR: In this paper, the activity coefficients at infinite dilution, γ 13 ∞ and gas-liquid partition coefficients, KL for 62 solutes: alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, butanal, nitrogen compounds and water in the ionic liquid trihexyl-tetradecyl-phosphonium tricyanamide were determined by gas liquid chromatography.
TL;DR: In this article, the activity coefficients at infinite dilution for 46 solutes, including alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, ethers, ketones, esters, aldehyde, acetonitrile, pyridine and 1-nitropropane in the ionic liquid (IL) 1-butyl-1-methylpyrrolidynium dicyanamide, [BMPYR][DCA] were determined by gas-liquid chromatography at
TL;DR: In this article, the authors present a Poisson-Fermi model and numerical methods for calculating the individual or mean activity coefficient of electrolyte solutions with any arbitrary number of ionic species in a large range of salt concentrations and temperatures.
Abstract: The combinatorial explosion of empirical parameters in tens of thousands presents a tremendous challenge for extended Debye-Huckel models to calculate activity coefficients of aqueous mixtures of the most important salts in chemistry. The explosion of parameters originates from the phenomenological extension of the Debye-Huckel theory that does not take steric and correlation effects of ions and water into account. By contrast, the Poisson-Fermi theory developed in recent years treats ions and water molecules as nonuniform hard spheres of any size with interstitial voids and includes ion-water and ion-ion correlations. We present a Poisson-Fermi model and numerical methods for calculating the individual or mean activity coefficient of electrolyte solutions with any arbitrary number of ionic species in a large range of salt concentrations and temperatures. For each activity-concentration curve, we show that the Poisson-Fermi model requires only three unchanging parameters at most to well fit the corresponding experimental data. The three parameters are associated with the Born radius of the solvation energy of an ion in electrolyte solution that changes with salt concentrations in a highly nonlinear manner.