Search

The binary system of [Bmim][OAc] (1-butyl-3-methylimidazolium acetate) with NMP (N-methylpyrrolidone) is a potential effective cellulose solvent, and its physicochemical properties and solute–solvent interaction are important to design and understand its application. The physicochemical properties can infer the solute–solvent interaction of a system, especially for an infinite dilution; so, in this work, over the molality range 0.0–2.1 mol·kg−1 and temperature range 288.15–318.15 K, the density and absolute viscosity for the dilute solution of [Bmim][OAc] in NMP were measured and correlated. The apparent molar volume and the relative viscosity were calculated and correlated by Redlich–Rosenfeld–Meyer equation (including parameters V Φ 0 , Av, Bv) and Jones–Dole equation (including parameters D, F), respectively. Then, the structure behavior of [Bmim][OAc] on solution and the [Bmim][OAc]–NMP interaction were discussed based on the parameters V Φ 0 , Av, Bv, D, F, and the volume ratio r, limiting apparent molar expansibility E Φ 0 and the solvation number ns. The results show that [Bmim][OAc] acts as a structure-maker for the solution, the [Bmim][OAc]–NMP interaction is weaker than the interactions of cation–anion and NMP–NMP, and such effect becomes more and more obvious with increasing temperature. Finally, based on the interactions and the widely accepted solvation hypothesis, the possible better temperature to dissolve cellulose was discussed for the potential cellulose solvent. [ABSTRACT FROM AUTHOR]

The fluids near the solid substrate display different properties compared to the bulk fluids owing to the asymmetric interaction between the fluid and substrate; however, to the best of our knowledge, no work has been conducted to determine the interfacial properties of fluids experimentally. In this work, we combined a pycnometer with experimental measurements and data processing to determine the standard thermodynamic properties of interfacial fluids for the first time. In the study, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([Hmim][NTf2]) and titanium dioxide (P25) were chosen as the probes to prove the concept. It was found that, with the combination of the Gay-Lussac pycnometer and the colligative law, together with selecting a suitable solvent, it is possible and reliable to determine the standard molar volume of the immobilized [Hmim][NTf2]. Compared to the bulk phase, the molar volumes of [Hmim][NTf2] on the P25 surface reduce by 20.8%-23.7% at temperatures from 293.15 to 323.15 K, and the reduction degrees decrease with increasing temperatures. The newly determined standard thermodynamic data was used to obtain the model parameters of hybrid electrolyte perturbed-chain statistical associating fluid theory density functional theory (ePC-SAFT-DFT), and further predictions of the density of interfacial ionic liquids with different film thicknesses were proved to be reliable in comparison with the experiment results. [ABSTRACT FROM AUTHOR]

The hygrometric method is used to determine new thermodynamic data on water activity and saturated aqueous solution of the water/d-sucrose/ammonium dihydrogen phosphate (ADP) system in a wide range of NH4H2PO4 molality, ranging from 0.1 to 3 mol⋅kg−1, and for various d-sucrose contents from 0 to 4 mol⋅kg−1. Powder X-ray diffraction (XRD) and attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy were used to characterize the solid state. The Pitzer–Simonson–Clegg model (PSC) is used to fit the experimental data of osmotic coefficient obtained from water activities data. The predicted saturated aqueous solutions, with the PSC model, are in good agreement with experimental data. For the concentration inferior to 1 mol⋅kg−1, the negative deviation from ideality was shown with increasing the ADP concentrations. The estimated values of the activity coefficient of d-sucrose, activity coefficient of ADP, and the Gibbs energy of transfer of ADP from water to mixture (water/d-sucrose) show that both ADP and d-sucrose exert significant salting-out effects on the aqueous solution. [ABSTRACT FROM AUTHOR]

Aqueous solutions are crucial to most domains in biology and chemistry, including in energy fields such as catalysis and batteries. Water‐in‐salt electrolytes (WISEs), which extend the stability of aqueous electrolytes in rechargeable batteries, are one example. While the hype for WISEs is huge, commercial WISE‐based rechargeable batteries are still far from reality, and there remain several fundamental knowledge gaps such as those related to their long‐term reactivity and stability. Here, we propose a comprehensive approach to accelerating the study of WISE reactivity by using radiolysis to exacerbate the degradation mechanisms of concentrated LiTFSI‐based aqueous solutions. We find that the nature of the degradation species depends strongly on the molality of the electrolye, with degradation routes driven by the water or the anion at low or high molalities, respectively. The main aging products are consistent with those observed by electrochemical cycling, yet radiolysis also reveals minor degradation species, providing a unique glimpse of the long‐term (un)stability of these electrolytes. [ABSTRACT FROM AUTHOR]

The effect of the lithium salt LiTFSI molality into the PEO-based electrolyte on the ionic conductivity was investigated in this work. To begin, the experimental evolution of LiTFSI-PEO electrolyte's ionic conductivity as a function of molality was analyzed, and hypotheses were put out to explain how ionic transport occurs in a heterogeneous microstructure of polymer electrolytes. To forecast the ionic conductivity in the electrolyte LiTFSI-PEO as a function of molality, an empirical mathematical model was then proposed, taking the phenomena predicted to occur into account. The proposed theoretical model presupposes that lithium salt's solvation state (total or partial solvation) and the steric effect brought on by heterogeneous areas are related to the conduction of ions (at the microscopic scale). The model is adjusted to accurately depict the entire experimental curve, which is thought to have three distinct domains. In the first domain, where the molality m is less than 1 mol/kg, the oxygen atoms completely solvate the lithium salt. The conduction is believed to be favorable in this situation since the released solvated lithium ions linearly fluctuate against the molality. The partial solvation of lithium corresponds to the second domain (1 mol/kg ≾ m ≾ 2 mol/kg), where the conductivity of the polymer electrolyte slightly increases with increasing molality. In the third domain, where m is greater than 2 mol/kg, the loss in ionic conductivity is caused by steric effects, as some of the lithium salt (LiTFSI) does not ionize and becomes immobilized, obstructing the transport pathway. Finally, the model was expanded to include how temperature affects ionic conductivity. The prediction model was effectively validated when it was put up against the findings of experiments conducted by various authors. [ABSTRACT FROM AUTHOR]

Fluid-mediated calcium metasomatism is often associated with strong silica mobility and the presence of chlorides in solution. To help quantify mass transfer at lower crustal and upper mantle conditions, we measured quartz solubility in H2O-CaCl2 solutions at 0.6–1.4 GPa, 600–900 °C, and salt concentrations to 50 mol%. Solubility was determined by weight loss of single-crystals using hydrothermal piston-cylinder methods. All experiments were conducted at salinity lower than salt saturation. Quartz solubility declines exponentially with added CaCl2 at all conditions investigated, with no evidence for complexing between silica and Ca. The decline in solubility is similar to that in H2O-CO2 but substantially greater than that in H2O-NaCl at the same pressure and temperature. At each temperature, quartz solubility at low salinity (XCaCl2 < 0.1) depends strongly on pressure, whereas at higher XCaCl2 it is nearly pressure independent. This behavior is consistent with a transition from an aqueous solvent to a molten salt near XCaCl2 ~0.1. The solubility data were used to develop a thermodynamic model of H2O-CaCl2 fluids. Assuming ideal molten-salt behavior and utilizing previous models for polymerization of hydrous silica, we derived values for the activity of H2O (aH2O), and for the CaCl2 dissociation factor (α), which may vary from 0 (fully associated) to 2 (fully dissociated). The model accurately reproduces our data along with those of previous work and implies that, at conditions of this study, CaCl2 is largely associated (<0.2) at H2O density <0.85 g/cm3. Dissociation rises isothermally with increasing density, reaching ~1.4 at 600 °C, 1.4 GPa. The variation in silica molality with aH2O in H2O-CaCl2 is nearly identical to that in H2O-CO2 solutions at 800 °C and 1.0 GPa, consistent with the absence of Ca-silicate complexing. The results suggest that the ionization state of the salt solution is an important determinant of aH2O, and that H2O-CaCl2 fluids exhibit nearly ideal molecular mixing over a wider range of conditions than implied by previous modeling. The new data help interpret natural examples of large-scale Ca-metasomatism in a wide range of lower crustal and upper mantle settings. [ABSTRACT FROM AUTHOR]

This work aims to explore the use of stable graphene oxide (GO) dispersions for enhanced carbon capture and oil recovery. The objective of the study was to explore novel GO dispersions for effective carbon utilization. Initially, the GO particles were synthesized via the modified Hummers method and dispersed in a 1000 ppm PAM solution. These solutions (0.1 and 0.3 wt% GO) were observed visually and using a particle size analyzer in which they did not show any instability of agglomeration for 28 days. Given their superior stability, the GO dispersions were then used for CO2 solvation in which the amount of CO2 solvated in the solution (molality) was ascertained using the well-established pressure depletion method. Increasing temperature was found to reduce the CO2 uptake while increasing pressure and GO concentration increased CO2 uptake. The GO dispersions were also able to resist CO2 escape from the system for over 200 h. Finally, the carbonated GO dispersions were used for EOR and were able to mobilize up to 61% of original oil in place (OOIP) from a sand-pack. The presented approach has potential for the development of a highly efficient CO2-based enhanced oil recovery method for sandstone reservoirs. [ABSTRACT FROM AUTHOR]

The anionic dimer H 5 P 2 O 8 - in potassium pentahydrogendiphosphate aqueous solutions was identified at ambient temperature. The solid phase of KH 5 P 2 O 8 (s) was synthesized and characterized using various analysis techniques. Raman spectroscopy was used to analyze qualitatively and quantitatively the pentahydrogendiphosphate ion in dilute and concentrated aqueous solutions. The formation and deformation bands of dimeric species in aqueous solutions were studied, therefore the obtained bands in the range of 300–1300 cm - 1 were examined as a function of molality of KH 5 P 2 O 8 aqueous solutions. Afterward, the obtained bands were compared to those of alkali orthophosphates that exhibit many differences. The attribution of the Raman lines is deduced from the known spectra of several orthophosphate solutions. The specific bands in the studied frequency range indicate the presence of dimeric anionic species of H 5 P 2 O 8 - in aqueous solutions. These observations denote the existence of intermolecular interactions between the phosphate anions in which P - OH and P - O bonds participate. These bands allow to exhibit the existence of the pentahydrogendiphosphate dimeric anion in aqueous solutions. [ABSTRACT FROM AUTHOR]

In this work, two strategies have been attempted to achieve decent fast-charging performances of Li-ion batteries. The first is to combine lithium bis(fluorosulfonyl)imide (LiFSI) and dimethoxyethane (DME) into an electrolyte for high ionic conductivity of the bulk electrolyte and the electrolyte-electrode interphases, and the second is to limit charging capacity within 80% state-of-charge (SOC) for stable capacity retention by lowering charging rate without increasing total charging time in the standard constant current-constant voltage (CC-CV) charging protocol. It is found that using 5 wt% fluoroethylene carbonate (FEC) as an additive enables the hybridization of 20 wt% DME into the electrolyte without adverse effects on the initial formation cycles and ongoing cycling in terms of coulombic efficiency and reversible capacity, and adding 2 wt% LiPF6 is beneficial to reducing charge-transfer resistance and stabilizing capacity retention. As a result, decent fast-charging performances are obtained from the 200 mAh graphite/LiNi0.80Co0.15Al0.05O2 pouch cells by using a 1.2 m (molality) LiFSI 3:5:2 ethylene carbonate (EC)/ethylmethyl carbonate (EMC)/DME + 5% FEC + 2% LiPF6 electrolyte (all by wt) and a modified CC-CV charging protocol consisting of CC charging at 4 C for a total of 12 min, which is the charging time equivalent to a 5 C charging protocol. [ABSTRACT FROM AUTHOR]

This study investigates the dissolution of calcite's (1 0 4) and (1 0 0) surfaces under alkaline conditions (pH 8.8–13.1) using vertical scanning interferometry under flow-through conditions. The dissolution rate of (1 0 0) surfaces decreases with increasing pH. For example, the dissolution rate at pH 8.8 is more than 20 times higher than that at pH 13.1. In contrast, the dissolution rate of (1 0 4) surfaces is far less sensitive to pH. We explain these observations as being on account of the preferential adsorption of [OH−] on (1 0 0) surfaces, inhibiting their dissolution. Particularly, this is because Ca-surface sites on (1 0 0) surfaces are less coordinated and have a stronger tendency for [OH−] adsorption. As a result, (1 0 0) surfaces dissolve nearly twice as fast as (1 0 4) surfaces at pH 8.8, whereas (1 0 4) surfaces dissolved ∼4.5 times faster than (1 0 0) surfaces at pH 13.1; indicating an inversion in dissolution behavior. The dissolution rate of (1 0 4) surfaces at pH 13.1 is 60 % of the rate at pH 10–12 because of the formation of slow dissolving microfacets of other orientations. The rhombohedral dissolution etch-pits formed on (1 0 4) surfaces, at lower pH's, disappeared upon exposure to solutions with pH > 12 and were replaced by protrusions. The addition of up to 4 m (molality) NaCl enhances the dissolution of (1 0 4) surfaces at pH 8.8–13.1 and (1 0 0) surfaces at pH 8.8–11.0, and inhibited the dissolution of (1 0 0) surfaces at pH = 12.0–13.1. In addition, the competing adsorption between OH− and CO 3 2− species mitigates the inhibition effects of CO 3 2− on both surfaces at pH 13.1 compared to pH 11, and the dissolution of (1 0 0) surfaces is far less affected by CO 3 2− than (1 0 4) surfaces. These results provide new insights into the rates and mechanisms of how crystallographic orientations affect calcite's dissolution at alkaline pH conditions. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Volumetric properties for ten binary mixtures, containing N3-substituted 1-methylimidazolium chloride ionic liquids, [Cnmim][Cl] (n = 0, 1, 2, 4, 6) and butan-2-ol or butan-2-one investigated in the molality range of ionic liquids (m = 0.005–0.1 mol·kg−1), and in temperature range T = (278.15–313.15 K) at 5 K intervals. From measured density data, the thermal expansion coefficient, α p , apparent molar volume, V ϕ , partial molar volumes for solvent, V ¯ 1 and solute, V ¯ 2 , apparent molar volume at infinite dilution, V ϕ o , Masson's interaction coefficient, Sv, Heppler's coefficient, ∂ 2 V ϕ o ∂ T 2 p , and limiting apparent molar expansibility, E ϕ o , were calculated. Masson's equation satisfactorily correlated with the calculated data. Based on the Sv coefficient, the interactions between cation and anion of the ionic liquids with butan-2-ol or butan-2-one are discussed. Ionic liquids [C0mim][Cl], [C4mim][Cl], and [C6mim][Cl] have structure-making properties, while [C1mim][Cl] and [C2mim][Cl] are structure-breakers in butan-2-ol. In butan-2-one solvent, the ionic liquid [C0mim][Cl] is a structure-breaker, while the other ionic liquids are structure-makers. [ABSTRACT FROM AUTHOR]

A thermodynamic and kinetic study of the dissolution properties of urea phosphate (UP) in water is performed using a Calvet type microcalorimeter. Calorimetric measurements reveal the dissolution is endothermic and the heat is perfectly proportional to the amount of UP dissolved, yielding an enthalpy of (33.755 ± 0.65) kJ/mol. By combining the enthalpy data of our measurements and literature, we derive the enthalpies of urea‐phosphoric acid adduct reaction, formation of solid UP and UP dissociation. Dissolution kinetics parameters are estimated using the collected dynamic calorimetric data that are well represented with quasi‐second‐order kinetic model, giving an activation energy of (16.7 ± 2.7) kJ/mol. Thermodynamic modeling of the pH difference between UP and phosphoric acid solutions shows the degree of UP dissociation decreases from 74% to 42% when UP molality increases from 0.02 to 1 mol/kg. Furthermore, the species molality distributions in UP solutions are calculated based on mass balance and the dissociation equilibrium relations considered. [ABSTRACT FROM AUTHOR]

This research demonstrates the synthesis of GGBS-based ready-mix (one-part) geopolymer (RMG) utilizing MBS as partial replacement to GGBS (10, 20 and 30 % by-mass) in addition to solid-alkaline reagents (NaOH-flakes and Na 2 SiO 3 powder) using thermal and mechanical treatments, resulting in the formation of "ready-to-use" geopolymer product, "just-add-water" alike cement. The RMG was characterized by analyzing mineral phases, functional-groups identification followed by surface-morphology and elemental analysis at multiple stages, and engineering properties such as setting-time, flowability, compressive strength and ultrasonic-pulse-velocity were evaluated under ambient curing condition. The results show that GGBS-MBS-based RMG has dense morphology, affirming the development of C-S-H and C(N)-A-S-H gels due to its amorphous nature with some crystalline-phases (SiO 2) which are in-linked to Si-O-Si and Al-O-Si bonds. The dry-mix of GGBS with powdered-Na 2 SiO 3 and 4 m molality NaOH (Na 2 SiO 3 /NaOH=1), pre-heated at 105±5°C for 6 h, followed by 6 h ball-milling with 20 % MBS replacement, achieved the highest 28-day compressive strength of 72.8 MPa, 10 % higher than the referenced mix and had satisfactory UPV results. The RMG not only solves handling problems caused due to concentrated aqueous-alkaline reagents used in two-part geopolymer synthesis but also provides sustainability by utilizing industrial and agricultural waste/by-products, hence reducing Portland cement demand, carbon footprint and waste-disposal issues. • GGBS-based 'RMG' utilizing MBS as partial replacement with solid-alkaline reagents using thermal and mechanical treatments. • Synthesis involves pre-heating of dry mix followed by mechanical treatment to get RMG cementing powder – 'just-add-water'. • Engineering and multi-stage microstructural properties of ready-mix geopolymer were evaluated. • Replacement of micronized biomass silica up to 20 % with GGBS improves the performance of the RMG. • RMG can reduce issues related to concentrated aqueous alkaline reagents often encountered in two-part geopolymer synthesis. [ABSTRACT FROM AUTHOR]

• Thermodynamic properties of ferric or magnesium chlorides in aqueous solution were investigated at different temperatures. • Water activities were measured for salts chlorides using the hygrometric method over a molality range to m max (FeC l 3) = 2.500 mol · k g − 1 and to saturated solutions m s (MgC l 2). • Four thermodynamic models were developed to evaluate the relevant properties. • Based on literature emf data for MgC l 2 (aq) at T = 298.15 K, the recommended activity coefficients were given at various temperatures. • Ln K s p ∘ of MgC l 2 (aq) were determined at different temperatures and compared with those of literature. The investigation of the thermodynamic properties of binary systems of ferric and magnesium chlorides in aqueous solutions was reported at various temperatures using both the hygrometric method and thermodynamic modeling. Water activities were measured over a molality range of 0.100 up to m max (FeC l 3) = 2.500 mol · k g − 1 and to m max (MgC l 2) = (5.798, 6.090, 6.394, and 6.839) mol · k g − 1 at temperatures from 298.15 K to 353.15 K, respectively. From the new measurements, the osmotic coefficients of water were evaluated and compared with the existing literature data at ambient temperature. These coefficients were treated at various temperatures using established thermodynamic models of the Pitzer, Filippov–Charykov–Rumyantsev, extended ion interaction, and Clegg–Pitzer–Brimblecombe. The relevant properties of ferric and magnesium electrolyte solutions were determined in the temperature range. Indeed, the parameterizations of FeC l 3 (aq) and MgC l 2 (aq) were evaluated and employed for the computation of solute activity and osmotic coefficients. Based on literature emf data for MgC l 2 (aq) at a temperature of 298.15 K, the consistency of the activity coefficients was evaluated using an adequate model, and an excellent description of the prediction activity coefficients is obtained by the extended ion interaction model. Then, the recommended activity coefficients were given at various temperatures by extending this procedure. An experimental investigation was also carried out to evaluate the solubility equilibrium of MgC l 2 in aqueous solutions at different temperatures. The solubility product and standard Gibbs energies of dissolution and formation were also calculated at different temperatures and compared with those existing in the literature. [Display omitted] [ABSTRACT FROM AUTHOR]

• A surrogate model based on conditional deep convolutional generative adversarial network (cDC-GAN) is developed. • Trained cDC-GAN can accurately determine the distribution of CH 4 in shallow unconfined aquifers, both qualitatively and quantitatively. • cDC-GAN can facilitate predicting the multiphase flow behavior in energy and environmental applications. Numerical modeling is an essential tool for geoscience applications involving multiphase flow behavior. Performing numerical simulation is, however, computationally intensive due to multi-scale, non-linear, and multi-physics nature of mechanisms controlling multiphase flow dynamics. Additionally, the computational challenges associated with traditional numerical simulations limit their applicability for repetitive simulations required in inverse modeling, uncertainty analysis, and optimization tasks. To overcome these limitations, surrogate modeling has recently emerged as a viable solution. A surrogate model, which functions as a regression model, is trained using numerical simulation data. It approximates the input–output relationships within a dynamic fluid environment. We design surrogate models, based on conditional deep convolutional generative adversarial network (cDC-GAN), to map the cross-domain between input and output pairs in a multiphase multicomponent system, focusing on methane (CH 4) migration in shallow unconfined aquifers. The cDC-GAN technique is selected due to its ability to generate high-fidelity surrogate models that effectively capture complex spatial distributions and heterogeneities. This technique excels in handling high-dimensional data, learning the intricate relationships between inputs and outputs, and producing realistic representations of subsurface phenomena. The trained cDC-GANs consider capillary entry pressure heterogeneity as input because this geologic attribute places first-order control on CH 4 migration in subsurface. The outputs include CH 4 saturation, water saturation, residual saturation of CH 4 , CH 4 mole fraction, and CH 4 molality. For each output, a separate cDC-GAN model is trained. Once trained, cDC-GANs can at any given time determine CH 4 distribution in a shallow unconfined aquifer, both qualitatively and quantitatively. The cDC-GAN approach can be considered as a valuable complement to numerical simulations for predicting multiphase flow behavior in other geoscience-, energy-, and environmental applications such as contaminant transport, hydrocarbon production, and geological carbon dioxide and hydrogen storage. [ABSTRACT FROM AUTHOR]

In this work, a theoretical thermodynamic model based on dissolution enthalpy was established to predict the osmotic and mean ion activity coefficients of metal chloride aqueous solutions. The dissolution enthalpies of CuCl2, CoCl2 and MnCl2 hydrates were measured from 298.15 to 323.15 K with the molality range from 0.1 to 3.0 mol·kg−1. Then the dilution enthalpies can be further calculated at corresponding temperature and molality. Therefore, with arbitrary temperature and molality, the osmotic and mean ion activity coefficients of the three solutions within the experimental condition can be calculated through the established model. The calculated results were consistent with the published data which indicates the thermodynamic model was reliable and acceptable. [ABSTRACT FROM AUTHOR]

Densities for aqueous lithium pentaborate solutions at the molalities of (0.011–0.976) mol kg−1 were measured with an Anton Paar Digital vibrating-tube densimeter at temperature intervals of 5 K from 288.15 to 323.15 K. The coefficient of thermal expansion (α), apparent molar volume (), apparent molar expansibility () and limiting apparent molar expansibility () were obtained based on the experimental density data. On the basis of the Vogel–Tamman–Fulcher equation, the coefficients of the correlation equation for densities of LiB5O8(aq) against temperature and molality were parameterized. The results suggest a strong solute-solvent interaction in the solution, and lithium pentaborate is classified as a "structure breaking" solute. As temperatures rise, the hydrophilic character becomes unapparent. [ABSTRACT FROM AUTHOR]

The specific ion theory (SIT) is a convenient ion activity coefficient model that is often used in solubility and solution equilibrium studies. However, its accuracy is limited. The SIT model can be improved by adding higher-order terms, and by allowing cation–cation, and anion–anion interactions. However, extensions of the SIT model tend to lead to a rapidly increasing number of higher-order interaction parameters that need to be known for reliable predictions. Using the analogy of multicomponent extensions of the Redlich–Kister/Margules model, this paper determines how far a virial-type activity coefficient model can be extended before it becomes unmanageable. It was found that a second-order extension of the SIT model is manageable. A first-order model is sufficient to describe Harned's Rule satisfactorily. It is found that the addition of like-ion interaction parameters (i.e., cation–cation interactions and anion–anion interactions) to the SIT model substantially improves Harned's Rule calculations, with an error reduction of over 50%. The ion interaction parameters are presented. Like-ion interactions should be interpreted as competitive effects between ion-water interactions rather than direct ion-ion interactions. Using concentration or mole per kg solution (modified molality) as a measure of abundance does not improve the accuracy of a first-order ESIT model but the modified molality scale does improve the accuracy of a 2nd-order ESIT model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Measured results of CO solubility in water & brine at high pressures were reported. • The first data for CO solubility in brine with high molalities of salt. • The results were well modelled by Krichevsky-Kasarnovsky model. • The Søreide and Whitson equation of state represented the results even better. • Both modelling approaches with the determined parameters can predict CO solubility. Experimental measurements of CO solubility in water and in NaCl(aq) solutions are reported at temperatures, pressures and salt molalities of relevance to geological carbon storage: (323.15 to 423.15) K, (2 to 28) MPa and (2 and 4) mol·kg−1, respectively. The expanded relative uncertainty of the CO solubility is estimated to be 4.4% at 95% confidence intervals. This study provides the first data for CO solubility in brine with high molality of salt. The results from this study were used to develop simple models for the solubility of CO in aqueous NaCl solutions as a function of temperature, pressure and salt molality dependent, up to 4 mol·kg−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Binary aqueous solutions of five organic salts were prepared. • Liquid densities were measured and correlated with salt molality. • Vapour pressures and osmotic coefficients were determined. • The Extended Pitzer Model of Archer was applied in the modelling of electrolytes. • Mean molal activity coefficients and excess Gibbs free energies were calculated. Due to the eco-friendliness of organic salts, they have been gradually replacing other electrolytes in different fields of chemistry. For example, they provide biocompatible salting-out agents for liquid–liquid extractions and earth-abundant materials for flow batteries. Nevertheless, reliable liquid density and vapour pressure data, which are paramount for a proper parameterisation of thermodynamic models, are often hard to find for aqueous solutions of organic salts, delaying the development of these technologies. In this work, the liquid density (ρ) of five binary aqueous solutions of organic salts (disodium tartrate, sodium potassium tartrate, dipotassium tartrate, trisodium citrate and tripotassium citrate) were measured and correlated at 298.15 and 313.15 K and 0.1 MPa. In these assays, second-degree polynomials provided determination coefficients (R 2) larger than 0.9982 in the correlation of liquid density with salt molality, for which a very accurate description of this property was accomplished. Moreover, vapour pressure osmometry (VPO) studies were carried out for these solutions at 313.15 K and 0.1 MPa. Then, the obtained osmotic coefficients (ϕ) were successfully modelled using the Extended Pitzer Model of Archer, yielding standard deviations (σ ϕ) lower than 8.61·10-3. Finally, the mean molal activity coefficients (γ ±) and excess Gibbs free energies (G E / R T) of the binary aqueous solutions of organic salts were effectively calculated, with potassium- and tartrate-based salts attaining significantly higher values than the ones composed of sodium and citrate, hinting at a more ideal solution behaviour of the former. [ABSTRACT FROM AUTHOR]

The utilization (absorption and areal sweep) of injected carbon dioxide (CO 2) can be enhanced if a viscous and agglomeration free nanofluid is used as most of the nanoparticles (NPs) prefer to stay in bulk phase rather than adsorbing on CO 2 surface. NP adsorption can be improved if non-participating NPs are surface modified with a suitable surface modifying agent e.g. , triethoxy (vinyl)silane (TVS). Thus, in this study, single-step approach was used to synthesize agglomeration free TiO 2 nanofluid whose surface modification was carried out in varying proportion of TVS (1–5% v/v) followed by the discussion on comparative CO 2 absorption and storage performance by different tools such as DLS, IFT, Rheology, Contact-angle, and Micromodel flow. The basic nanofluid (T o) showed greater CO 2 absorption after surface modification as demonstrated by molality results. However, surface modification also decreased dispersion stability of surface modified nanofluids (T 1 , T 2 , and T 3) and T 2 was regarded as the most stable nanofluid with −64.4 mV (ζ-potential) and 153 nm (NP size). After surface modification, increase in NP size and settlement was higher for surface modified nanofluids than T o , which exhibited dispersion stability of 84 d with −53.4 mV and 15 nm. Contact angle results also showed that surface modified nanofluids possess greater affinity for CO 2 absorption than basic nanofluid (T o). Rheological analysis was also consistent with other tests where viscosity was found dependent on both storage period and temperature, and NP settlement was found to be the most influential parameter on flow properties of nanofluid. Finally, pore scale analysis was performed to understand areal sweep of injected CO 2 in micromodel with and without nanofluid, where nanofluid imparted greater CO 2 storage by diverting it in un-swept pore networks of micromodel which were untapped by CO 2 without nanofluid. • Surface modified single-step TiO 2 nanofluid was used for CO 2 absorption and storage. • The size and dispersion stability of nanofluid was dependent on surface modifying agent. • Rheological property of nanofluids was investigated as a function of time and temperature. • Nanofluids showed least wetting on rock surface after surface modification. • Micromodels were used to envisage CO 2 storage with/without nanofluid at pore scale. [ABSTRACT FROM AUTHOR]

[Display omitted] • Establishing the Raman quantification curves of alkali sulfates at 25 °C to 250 °C. • Obtaining the correlation of quantitative calibration coefficient k and the temperature T. • Evaluating the potential application in determining sulfate content of FIs. The quantitative study of the sulfate content in natural fluid inclusions (FIs) will help our understanding of the processes of metal transport and related mineralization. The sulfate-rich FIs typically contain several types of sulfates with diverse cations such as Na+, K+, and so on. In order to get the sulfates contents in natural FIs, in situ Raman spectral quantitative calibration method is used to calibrate the Li 2 SO 4 , Na 2 SO 4 , K 2 SO 4 and Cs 2 SO 4 solutions at temperatures ranging from 25 °C to 250 °C in our study. The results show that the A (SO 4 2−)/ A (H 2 O) ratio increases linearly with increasing m SO 4 2− in sulfate solutions containing single cation of Li, Na, K or Cs at the set temperatures, where A is Raman peak area and m is molality (mol/kg H 2 O), and a negative linear relationship exists between k (quantitative calibration coefficient) and temperature for sulfate solutions with specific cations up to 250 °C. Meanwhile, the slopes and the intercepts of the k-T correlation curves are obviously different among sulfate solutions with different cations, and the coefficients k of these sulfate solutions at certain temperature decrease with the increase of atomic number of the cation, in accordance with the following order: Li+ > Na+ > K+ > Cs+. As Na+ and K+ are the main cations in the natural sulfate-bearing FIs, the quantification of the multi-cation (Na ± K ± Li) sulfate solutions was evaluated by using the Raman quantitative calibration curves of Li 2 SO 4 , Na 2 SO 4 , K 2 SO 4 and Cs 2 SO 4 separately, the errors exist due to the use of calibration curves with different cations; the average concentration errors derived from the use of Na 2 SO 4 or K 2 SO 4 Raman quantitative calibration curves are within about 5 %, while those from the use of Li 2 SO 4 or Cs 2 SO 4 Raman quantitative calibration curves are within about 15 %. Therefore, the acceptable errors suggest that the calibration curves of individual sulfates can be applied to the determination of sulfate content of natural sulfate-bearing FIs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Temperature-dependent standard molar volumes and expansibilities of water in tert -butylamine were determined densimetrically. • Density measurements were performed with an error being about 0.03 kg·m−3 at T = (278.15 to 303.15) K and ambient pressure. • A temperature-induced effect of "partial molar isobaric compaction" of the solute (PMICS) in the amine studied was found. • PMICS is due to an increasingly marked difference in rates of volume expansion of structures in solvation shell and in bulk. Densities of water solutions in tert -butylamine (t -BuNH 2) with the solute molality from ca. (0.015 to 0.35) mol∙(kg solvent)−1 were measured at six temperatures, from T = (278.15 to 303.15) K, and p ∼ 0.1 MPa. The uncertainty in density measurements did not exceed 0.03 kg m−3. The standard (apparent at infinite dilution) molar volumes and expansibilities of water as a solute in t -BuNH 2 were calculated. The origins for the phenomenon of the temperature-induced relative partial molar isobaric compaction of a solute (PMICS) in the system under study were discussed based on Ben-Naim's concept of the "relative affinity parameter". [ABSTRACT FROM AUTHOR]

[Display omitted] • Diphenylsulfoxide is an amphiphilic homolog of DMSO featuring enhanced hydrophobicity. • Diphenylsulfoxide surprisingly exhibits outstanding solubility in methanol and high solubility in acetonitrile. • The strong diphenylsulfoxide-methanol hydrogen bonding is a prerequisite for high solubility. • The partial molar volume of diphenylsulfoxide in acetonitrile is larger than that in methanol. Diphenylsulfoxide (Ph 2 SO) represents a noteworthy organic substance composed of bulky amphiphilic molecules. The chemical interest in Ph 2 SO arises from a peculiar combination of the strongly polar and strongly nonpolar moieties which are uniquely packed. The solubility of Ph 2 SO in conventional organic solvents is a cornerstone of its prospective applications. In the present work, the full concentration ranges of the possible homogeneous solutions of diphenylsulfoxide (Ph 2 SO) in acetonitrile (ACN) and methanol (MEOH) have been investigated by densitometry, UV–vis, FTIR spectroscopy, and quantum-chemical calculations. For the first time, we unraveled an outstanding solubility of Ph 2 SO in MEOH. The homogeneous solutions form up to the molality of 0.9 mol kg−1. This observation is unexpected from the conventional chemical wisdom because Ph 2 SO contains twenty-two non-polar interaction sites vs. two polar interaction sites. Based on the volumetric measurements, we revealed that the partial molar volumes of Ph 2 SO depend somewhat on solvent (MEOH, ACN) peculiarities. The effects of solvent on the spectral characteristics of diphenylsulfoxide have been considered. The numerical simulations based on the systematic potential landscape exploration corroborate the existence of several types of supramolecular species involving Ph 2 SO and solvent molecules simultaneously. The peculiar anisotropic Ph 2 SO-MEOH coupling, which is a strong hydrogen bonding, along with the small size of the solvent molecules is responsible for the recorded outstanding solubility in the methanol media. In turn, the performance of ACN is somewhat less encouraging notwithstanding the way higher dipole moment of its molecules. As an amphiphilic solute, Ph 2 SO may boost the solubilities of hydrophobic solutes by interfacing its coupling with polar media. The reported results inspire further explorations of Ph 2 SO to design task-specific liquid systems. [ABSTRACT FROM AUTHOR]

• Water activity of AlC l 3 (aq) was measured in the molality and temperature ranges • Osmotic and activity coefficients were evaluated using the Pitzer, EII, and CPB models • Solubility of anhydrous AlC l 3 was determined experimentally from 298.15 to 353.15 K • Solubility products of AlC l 3 (aq) were calculated at various temperatures The vapor-liquid-solid equilibria and thermodynamics data relevant to aluminum chloride in aqueous solutions were investigated at various temperatures. The water activity measurements of AlC l 3 (aq) were carried out from dilution to saturated solutions at temperatures ranging from 298.15 to 353.15 K using the hygrometric method. From new experimental results, the ion interaction of Pitzer, extended ion interaction (EII) and Clegg–Pitzer–Brimblecombe (CPB) models were developed to allow the parametrization of the binary system. The interaction parameters were evaluated for the Al − Cl − H 2 O system and used to calculate the solute activity and osmotic coefficients form the three models. The standard approach for a 3–1 electrolyte with the ion parameters in the temperature range shows a very good agreement with osmotic coefficient data for unsaturated solutions. The solubility equilibrium of anhydrous AlC l 3 in aqueous solutions was determined experimentally up to m m a x = (3.383 to 3.606) mol · k g − 1 from (298.15 to 353.15) K respectively; then, the solubility products as Ln K s p ∘ of AlC l 3 (aq) were also given using the obtained activity coefficients at various temperatures. [Display omitted] [ABSTRACT FROM AUTHOR]