Simple Mixing Rule Research Articles

Thermophysical properties of the liquid organic hydrogen carrier system based on benzyltoluene considering influences of isomerism and dissolved hydrogen

The benzyltoluene (BT)-based liquid organic hydrogen carrier (LOHC) system currently considered for large-scale applications represents a mixture of regioisomers. To characterize this complex system, a comprehensive experimental database for various thermophysical properties of synthesized BT isomers and their mixtures without and with the presence of hydrogen (H2) close to vapor-liquid equilibrium is established using optical and conventional techniques at process-relevant temperatures and pressures up to 573 K and 6 MPa. The surface tension varies by less than 4% among the dehydrogenated (H0-BT) or hydrogenated (H12-BT) isomers. The density and viscosity of mixtures of H0-BT or H12-BT isomers can be described by simple mixing rules with average absolute relative deviations of 0.022% and 0.38%. With increasing H2 pressure, the viscosity remains nearly constant, while the interfacial tension decreases by up to 5%. The thermal and mutual diffusivity of H12-ortho-BT containing dissolved H2 at 6 MPa decrease and increase with increasing temperature.

PHAHST Potential: Modeling Sorption in a Dispersion-Dominated Environment.

PHAHST (potentials with high accuracy, high speed, and transferability) is a recently developed force field that utilizes exponential repulsion, multiple dispersion terms, explicit many-body polarization, and many-body van der Waals interactions. The result is a systematic approach to force field development that is computationally practical. Here, PHAHST is employed in the simulation for rare gas uptake of krypton and xenon in the metal-organic material, HKUST-1. This material has shown promise in use as an adsorptive separating agent and presents a challenge to model due to the presence of heterogeneous interaction sorption surfaces, which include pores with readily accessible, open-metal sites that compete with dispersion-dominated pores. Such environments are difficult to simulate with commonly used empirical force fields, such as the Lennard-Jones (LJ) potential, which perform better when electrostatics are dominant in determining the nature of sorption and alone are incapable of modeling interactions with open-metal sites. The effectiveness of PHAHST is compared to the LJ potential in a series of mixed Kr-Xe gas simulations. It has been demonstrated that PHAHST compares favorably with experimental results, and the LJ potential is inadequate. Overall, we establish that force fields with physically grounded repulsion/dispersion terms are required in order to accurately model sorption, as these interactions are an important component of the energy. Furthermore, it is shown that the simple mixing rules work nearly quantitatively for the true pair potentials, while they are not transferable for effective potentials like LJ.

Testing mixing rules for structural and dynamical quantities in multi-component crowded protein solutions.

Crowding effects significantly influence the phase behavior and the structural and dynamic properties of the concentrated protein mixtures present in the cytoplasm of cells or in the blood serum. This poses enormous difficulties for our theoretical understanding and our ability to predict the behavior of these systems. While the use of course grained colloid-inspired models allows us to reproduce the key physical solution properties of concentrated monodisperse solutions of individual proteins, we lack corresponding theories for complex polydisperse mixtures. Here, we test the applicability of simple mixing rules in order to predict solution properties of protein mixtures. We use binary mixtures of the well-characterized bovine eye lens proteins α and γB crystallin as model systems. Combining microrheology with static and dynamic scattering techniques and observations of the phase diagram for liquid-liquid phase separation, we show that reasonably accurate descriptions are possible for macroscopic and mesoscopic signatures, while information on the length scale of the individual protein size requires more information on cross-component interaction.

Performance of predictive approaches for the viscosity of binary liquid mixtures of 1-alcohols

The objective of this study is to evaluate the predictive performance of three semi-theoretical approaches for modeling viscosity of binary liquid mixtures composed of 1-alcohols. For the mixtures that contain 1-alcohols with a similar number of carbon atoms, three schemes including the Rough Hard-Sphere model, the McAllister model, and UNIFAC-VISCO were demonstrated to be able to reproduce the mixture viscosity with an average deviation of 5%. For highly asymmetrical mixtures without the presence of small molecules, only McAllister-type model successfully reproduced the experimental values. The prediction done by the Rough Hard-Sphere model on the basis of using simple mixing rules for characteristic parameters indicated that this model should be further modified to improve its predictive capability.

A brief juxtaposition of the effects of combining rules on acid gas geosequestration at a constant temperature

Acid gases are hazardous to humanity, industries, the environment, and climate at large and their effects must be blunted as a matter of some urgency in mass-producing fields such as oil and gas for operations to be safely conducted. Diverse means of removal and safe storage exist, for which injecting these acid gases into geological formations (geosequestration) is an attractive one due to its economic viability and environmental friendliness. Some of these geological storage choices include depleted hydrocarbon reservoirs and deep saline aquifers. However, many interactions are in play during geosequestration and the one of interest in this work is the fluid-fluid interaction between the formation fluid (water) and injected fluid (acid gas). Various parameters are key to determining the safety, security, and containment of the injected plume to forestall leakage. Some of these parameters are interfacial tension, absorption, and dissolution of the injected fluid into the bulk water and adsorption of the injected fluid onto the interface of the formation water. Due to the extreme pressure and temperature circumstances, parameters may be hard to secure directly from the reservoir. Therefore, an indirect but reliable method of procuring these important parameters is required. Molecular dynamics offers a mechanism to model reservoir conditions and gain invaluable insight into the nature of interactions between the fluids involved. The modelling of molecular fluids can vary considerably depending upon several factors. Pairwise combining rules is one such factor, and in acid gas geosequestration, however, the influence of the effect of combining rules in the modelling of these fluids has garnered little attention thus far. In this work, we investigated the impact of three of the most common combining rules – Lorentz-Berthelot (arithmetic), geometric and the sixth power – and compared to available experimental data. We found that while some of the parameters compared showed only marginal statistical dissimilarities such as interfacial tension and radial distribution function, on an important front such as density both arithmetic and geometric mixing rules provided results closer to the experimental data. For simple molecules, we conclude, arithmetic and geometric mixing rules should suffice, insofar as the modelling is not for rare gases.

Higher alcohols as cosolvents of mixtures of ethanol and soybean oil: Solubility and physical properties of ternary systems

Mixtures of soybean oil (SO) and ethanol (EtOH) are of interest for several applications, such as the addition of the mixtures to diesel, the production of ethyl esters (ethyl biodiesel) from SO and the extraction of vegetable oils with a renewable solvent. However, the solubility between the components of this mixture is limited, which may hinder the possible applications. Thus, the present study aimed to determine the solubility of mixtures composed of SO and EtOH with the addition of cosolvents, n-butanol (nBut) and isoamyl alcohol (IAA), which are higher alcohols present in fusel oil, a coproduct of the production of EtOH. The physical properties of the ternary mixtures were also determined, which are necessary data for proposing the use of these renewable inputs. The regions of phase separation for the systems were determined using the cloud point method at constant temperature (25, 40 and 55 °C). The physical properties, density (ρ, kg·m−3) and dynamic viscosity (η, mPa·s) were experimentally determined for the binary (EtOH + nBut and EtOH + IAA, temperatures from 20.0 to 70.0 ± 0.1 °C) and ternary (SO + EtOH + nBut and SO + EtOH + IAA, 25.0, 40.0 and 55.0 ± 0.1 °C) mixtures. The experimental ρ data were described mathematically by the simple mixing rule (SMR) and the Jouyban-Acree (JA) model. For the description of η, the modified Kay rule (MKR), the Kendall and Monroe (KM) model, the Grunberg-Nissan (GN) model and the JA model were considered. Regarding the binary mixtures, the SMR and the GN model showed the lowest average relative deviation (ARD) values, 0 to 0.31% for ρ and 0.21 to 5% for η. For the ternary systems, the JA model best described the behavior of both physical properties (ARD from 0.02 to 4.51% for ρ and from 0.85 to 7.14% for η). Both cosolvents enabled the reduction of the immiscibility region, with similar performance in the evaluated temperature range.

Mixing rule for calculating the effective refractive index beyond the limit of small particles.

Considering light transport in disordered media, the medium is often treated as an effective medium requiring accurate evaluation of an effective refractive index. Because of its simplicity, the Maxwell-Garnett (MG) mixing rule is widely used, although its restriction to particles much smaller than the wavelength is rarely satisfied. Using 3D finite-difference time-domain simulations, we show that the MG theory indeed fails for large particles. Systematic investigation of size effects reveals that the effective refractive index can be instead approximated by a quadratic polynomial whose coefficients are given by an empirical formula. Hence, a simple mixing rule is derived which clearly outperforms established mixing rules for composite media containing large particles, a common condition in natural disordered media.

Some experimental and theoretical studies of diethylene glycol diethyl ether and 2-alkanol mixtures

Experimental density and dynamic viscosity data for the diethylene glycol diethyl ether +2-alkanol (C3 to C6) mixtures have been published at 293.15 K, 303.15 K, 313.15 K, and 323.15 K and at pressure of 0.1 MPa. Excess molar volume and deviation in dynamic viscosity were obtained from experimental data and correlated with Redlich–Kister equation, from the values obtained, the interaction forces were studied. Perturbed chain-statistical associating fluid theory equation of state was used for modeling the density for pure fluids and mixtures. Free volume theory coupled to Perturbed chain-statistical associating fluid theory equation of state was used to modeling the viscosity of pure fluids and mixtures; in the case of binary mixtures, we proposed a simple mixing rule and used the Pourabadeh et al. mixing rule. Good results in the prediction and correlation of experimental liquid density and dynamic viscosity for binary mixtures were obtained, 0.12% and 2.28%, respectively.

A mass transfer cavitation model for the numerical flow simulation of binary alkane mixture segregation

Based on the Rayleigh bubble dynamics equation a mass transfer model for cavitation of binary alkane mixtures is presented. Raoult's and Dalton's law, simple mixing rules, and an accurate Equation of State are utilized. The model is implemented into an in-house CFD code. For solver validation pure species literature cases are taken. The method is applied to a lighter n-octane/n-heptane and a heavier n-dodecane/n-heptane mixture in a rarefaction tube and a hydrofoil test case. Segregation of the species is observed during cavitation due to their different mass transfer rates. While for the lighter mixture, mass transfer of both species only moderately deviates, a significantly higher mass transfer of n-heptane compared to n-dodecane is observed for the heavier mixture, where the saturation pressure differs two orders of magnitude between the mixture ingredients. The strong segregation of the heavier mixture is associated with a predominant amount of n-heptane in the vapor phase. As a consequence, vapor composition is strongly affected by the volatilities of mixture ingredients.

Dissolution dynamics of woven all-silk composites fabricated in the ionic liquid 1-ethyl-3-methylimidazolium acetate

Single layer woven all-silk composites (ASCs) have been prepared using the ionic liquid 1-ethyl-3- methylimidazolium acetate ([C2mim][OAc]), with the dissolution carried out under various times and temperatures. Cross sectional images revealed the dissolved and coagulated silk matrix were formed along both fibre directions with thicker matrix layer observed along warp direction. Radial integration utilising the second Legendre polynomial function (P2) were conducted on the collected intensity distribution curves attained from WAXD azimuthal scans, enabling the quantitative measurement of the average orientation of crystals. A simple linear mixing rule was employed to correlate the coagulated matrix (Vm) with respective P2 values, leading to the calculation of Vm. Time–temperature superposition (TTS) was verified through the construction of master curves, from which the dissolution was found to have Arrhenius-like behaviour allowing the determination of dissolution activation energy (Ea). The three measured tensile properties were all found to follow TTS principle, thus yielding another two methods to determine Ea. Five different methods point to an average Ea value of 93±2 kJ/mol. Additionally, the dissolution rates and activation energies of single and woven silk were compared. The master curves constructed in this study may provide a guidance for future design of silk fibre reinforced composites with desired properties.

Cubic Plus GE (CPGE): Cubic equation of state with simple mixing rule plus excess Gibbs energy that satisfies low-density condition

The excess Gibbs energy calculated by activity coefficient model GE,M is added to a cubic equation of state. The additional term containing GE,M is obtained by a dimensional analysis. A simple mixing rule such as a/b = Σ(ai/bi)xi and b = Σbixi is adopted. The equation of state satisfies the low-density boundary condition that the second virial coefficient be quadratic in composition. The activity coefficient derived from the equation of state is expressed as the sum of Flory-Huggins term and interaction term, which has the same form as UNIQUAC, UNIFAC, and ASOG models at low pressure in liquid phase. Peng-Robinson equation of state was used for an example of cubic equation of state, and NRTL, CDSAP, and r-CDSAP models were adopted for GE,M for examples of activity coefficient models. The vapor-liquid equilibria for 2-propanol (1) + water (2), acetone (1) + water (2), benzene (1) + 2,2,4-trimethylpentane (2), methane (1) + pentane (2), and ethane (1) + heavy alkanes (2) systems were calculated to test the temperature dependency. The parameter values in the activity coefficient models were fitted to the experimental data of each binary system at the lowest temperature. Then, the vapor-liquid equilibria were calculated at higher temperatures with the parameter values. The calculated results at higher temperatures by the proposed model are better than those by Peng-Robinson + Wong-Sandler + NRTL mixing rule or Peng-Robinson + Huron-Vidal + NRTL mixing rule. The vapor-liquid equilibria for acetone (1) + acetonitrile (2) + benzene (3) + ethanol (4) system and its sub-binary and sub-ternary systems were calculated to test the estimation performance. The parameter values in the activity coefficient models were fitted to the experimental data of sub-binary systems. Then, the vapor-liquid equilibria for ternary and quaternary systems were estimated. The average deviations between the experimental data and the calculated results by the proposed model are 0.7% for pressure and 0.005 to 0.006 for mole fraction in vapor phase.

Prediction of phase equilibria, density, speed of sound and viscosity of 2-alkoxyethanols mixtures: A comparison study between SAFT type EoSs and a modified PR EoS

In this work, a modified Peng-Robinson equation of state with the Huron-Vidal-NRTL mixing rule was used to describe complex polar phase equilibria, density, speed of sound and viscosity at low pressure of alkoxyethanols/alkane, alkoxyethanols/isoalkanes and 2-butoxyethanol/water mixtures. The experimental data is gathered from the literature of a selected alkoxyethanols/alkanes series with the aim of developed generalized expressions for the binary interaction parameters required in the mixing rule model as a function of the RTc/Pc ratio of alkanes. In total 19 mixtures were analyzed (6 used in correlation and 13 mixtures used in prediction processes). For each type of mixture, the generalized expressions were obtained by fitting experimental liquid-liquid equilibria (LLE) data of 3 different mixtures at 100 kPa and to validate them, LLE and vapor-liquid equilibria (VLE) predictions were performed. Adequate results were obtained in all cases. Also, the predictive capabilities of the generalized EoS model have been tested using density, and speed of sound estimations. The overall deviation is below 1.10% for density and 6.84% for speed of sound. Also, the viscosity is correlated and predicted using a simple mixing rule coupled with the generalized EoS model and the absolute deviation is below 3.86%. Finally, two cases of study have been implemented to analyze the possibility of the generalized model to predict other branched-chain alkanes and water systems. The overall results indicated a good agreement with experimental data and proved that the EoS coupled with the Huron-Vidal mixing rule can describe high polar systems and their properties with acceptable and low deviations in comparison to other EoS such as SAFT types or CPA approaches.

Modeling of compressed liquid viscosity of hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, hydrochlorofluorocarbons and their mixtures

In this work, a semi-empirical viscosity model for hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), hydrochlorofluoroolefins (HCFOs), hydrochlorofluorocarbons (HCFCs) and their mixtures in the compressed liquid phase is presented based on the Modified Enskog Theory. The proposed viscosity model has 3 fitting coefficients per fluid and their values can be determined by the experimental compressed liquid viscosity data of the liquids of interest (The MATLAB code of the present viscosity model is attached in this paper). The results show that the present model can accurately reproduce the viscosities of the 18 liquids with the average absolute deviation of 1.93%. In addition, viscosities of 2 mixtures were calculated by the newly proposed model combining with a simple mixing rule, with the average absolute deviation of 2.01%. Additionally, the performance of the newly proposed scheme was compared with those of several conventional models.

Exploring tuning phenomena of THF-H2 hydrates via molecular dynamics simulations

The tuning phenomenon is one of the effective strategies to enhance the gas storage density of clathrate hydrates at moderate pressure: small gaseous guest molecules can occupy some of the large cages of binary hydrates that are not occupied by thermodynamic promoters. This work explored tuning phenomena in THF-H2 hydrates at the molecular level by all-atomic molecular dynamics simulations for the first time. Before conducting molecular dynamics simulations, off-diagonal Lennard-Jones (LJ) parameters between the center of mass of H2 and oxygen of H2O were optimized from ab-initio calculations with various configurations of H2 and H2O molecules. These optimized off-diagonal parameters provided reasonable phase equilibrium of THF-H2 hydrates compared to the simple mixing rule case, which is derived from weakened H2-H2O interaction and active drifting of H2 in molecules’ 512 cages. With the ab-initio modified LJ parameters, the growth of THF-H2 hydrates was investigated by molecular dynamics simulations under various compositions and pressures of the system. Cage occupancy of H2 in 512 cages of the binary hydrates increased when the THF concentration was lower than 5.56 mol%, but double occupation of H2 in 512 cages was not observed. Cage occupancy of H2 in 51264 cages significantly increased by lowering the THF concentration, and the total storage capacity of H2 increased by multiple occupations of H2 in the 51264 cages. The growth rate of the THF-H2 hydrates depended on the THF concentration, and that dependency of the growth rate was due to the wrong adsorption of THF molecules at open small cage sites of the solution-hydrate interface. These results demonstrated that uptake of H2 could be enhanced by the tuning phenomena when mobile THF molecules in the liquid phase formed binary hydrates with H2.

Meta-analysis of critical points to determine second virial coefficients for binary biopolymer mixtures

A method is introduced to extract virial coefficients from phase diagrams. Previous work demonstrated that the critical point of a phase diagram (two parameters) of a binary polymer mixture provides too little information to allow a full description of the phase diagram when using the Edmond-Ogston model (which requires three parameters). In this paper, it is shown that simultaneous analysis of multiple phase diagrams of binary polymer mixtures with shared components does allow the extraction of virial coefficients. The method is illustrated by analyzing phase diagrams for various polymer mixtures directly available in literature. The obtained virial coefficients for the polyethylene oxide/polyethylene glycol (PEO) and dextran polymers are compared to values as obtained by membrane osmometry and shown to be in satisfactory agreement. These virial coefficients are shown to follow a power-law dependence on the molecular weight. In addition, it is observed that the cross-virial coefficient can be approximately described by a simple mixing rule. This rule makes it possible to estimate the phase diagrams for polymer mixtures, where the virial coefficients of the pure components are known, but the cross-virial coefficient is unknown. The method to extract virial coefficients is also applied to a number of mixtures containing agarose, bovine serum albumin or gelatin, mixed with either PEO or dextran. The virial coefficients obtained in a simultaneous fit involving fitting the critical points of multiple phase diagrams are used to calculate the full original individual phase diagrams. Generally, there is good agreement between such a calculated phase diagram and the original experimental phase diagrams.

Comparison of volatility characteristics and temperature-dependent density, surface tension, and kinematic viscosity of n-butanol-diesel and ABE-diesel fuel blends

Climate strategies and targets are impossible to meet with the continuously expanding energy and transportation sectors without renewable liquid fuels. Butanol is a potential alternative fuel, however, its production cost is currently high. Therefore, acetone-butanol-ethanol (ABE), an intermediate fermentation product, can also be used as fuel, which is economically more competitive. This paper provides temperature-dependent measurement data of material properties of various n-butanol and ABE blends with EN 590 diesel fuel. The key findings are the following. Distillation curves and initial boiling points match up to 25% volume fraction of biofuel for n-butanol and ABE blends. Initial boiling point decreases exponentially with biofuel content and has no considerable change above 25% and 50% biofuel volume fraction for n-butanol and ABE blends, respectively. Curve fitting was performed for initial boiling point, density, surface tension, and kinematic viscosity data to provide an empirical model for simulations. The simple mixing rule was applicable to density and surface tension. Nissan-Grunberg equation for viscosity is only recommended with the binary interaction parameter that is negative for n-butanol and positive for ABE blends. Ohnesorge number has a minimum at 25% n-butanol volume fraction, showing a minimum in average droplet size, which is optimal for clean operation.

Will mixing rule or chemical reactions dominate the ash behavior of biomass mixtures in combustion processes on laboratory and pilot scales?

Mixing biomasses has a good potential to solve operational problems in thermochemical valorization processes related to ash behavior. Chemical reactions within the ash of the blend, and not only a mixing effect without reaction, need to take place to form new solid phases in the mixture at the expense of getting rid of the problematic liquid one to decrease the slagging tendency. The present work focuses on assessing the presence of a chemical reaction in comparison with a simple mixing effect within the ash of mixtures of wheat straw - oak bark biomass and ash in two laboratory setups and in a fixed and in a moving bed pilot combustion reactors. The operating conditions were varied to study their effects on the reactivity of the ash within the mixtures. This aimed to optimize the ash reactivity and to assess the capabilities of the laboratory test to predict the ash behavior in pilot-scale reactors.Mixing without reaction effect was more evident when mixtures of biomass were used on both laboratory and pilot scales. In this case, the simple mixing rule was able to simulate the general ash behavior of biomass mixture to a certain extent that exact prediction was always limited by the presence of certain chemical reactions. However, chemical reactions effect was dominant when mixtures of ash of biomass were applied as feedstock. Solid crystalline phases K2Ca2Si2O7 and K2Ca6Si4O15 were the direct end products of these chemical reactions. Their relative proportion was inversely proportional to the problematic amorphous phase in the final ash. Hence, optimizing the blend proportion to increase their concentrations has the potential to solve slagging problematic. These two compounds were mostly stable at 1000 ℃, at which equilibrium was reached after 6 h. However, they existed at a lower proportion at 850℃ and disappeared at 1200℃. The developed laboratory pellet test was also able to predict very efficiently the pilot ash behavior of both individual biomasses and their mixture in terms of crystalline and amorphous composition and proportion along with agglomeration distribution.

Simultaneous measurement of the density and viscosity for n-Decane + CO2 binary mixtures at temperature between (303.15 to 373.15) K and pressures up to 80 MPa

This work reports new experimental data for the density and viscosity of n-decane + CO2 binary mixtures. A simultaneous density and viscosity measurement apparatus was redesigned using a vibrating–wire viscometer coupled with a vibrating–tube densimeter. The measurements for the pure component (n-decane) and three different binary mixtures (n-decane + CO2), with mole fractions of n-decane of (0.4026, 0.2225, 0.1262), were carried out at temperatures ranging from (303.15 to 373.15) K and pressures up to 80 MPa. The expanded relative uncertainties (k = 2, level of confidence = 0.95) were estimated to be 0.2% for density and 3.0% for viscosity over the entire measurement range, respectively. Densities were correlated as a function of temperature and pressure through a modified Tait–type equation with an average absolute percentage deviation less than 0.05%. To model the viscosity of the binary mixtures as a function of temperature, density, and composition, the extended hard–sphere method combined with simple quadratic mixing rules were used to describe our experimental data. Good agreement is found between experiments and correlations, which attests to the predictive capabilities of semi–empirical equations. In addition, Monte Carlo simulations in the isobaric-isothermal ensemble with the Transferable Potential for Phase Equilibria–United Atom (TraPPE–UA) force field were carried out to characterize the microscopic structure of the studied systems.

An Investigation on the Viscosity Reduction of Iranian Heavy Crude Oil through Dilution Method

An increase in the global energy demand and also the shortage of conventional crude oil resources have led to an increase in the attention to unconventional crude oil resources. However, unconventional crude oils need additional processes which make their production and refining costly. Therefore, some techniques including heating, dilution, or creating oil in water emulsions have been proposed to solve this problem. In the present study, the dilution method has been investigated to reduce the viscosity of heavy Iranian crude oil produced in the Nowrouz field which has a viscosity of 608 mPa.s and API of 19.5 at 25°C. After a preliminary diluent selection, the examined diluents were kerosene, diesel, and toluene in the range of 5-30% v/v in 25°C. It was found that using toluene at 30% v/v reduces the viscosity of crude oil/diluent blend up to 97% in comparison with initial crude oil. To predict the viscosity of crude oil/diluent blend, simple mixing rules and mixing rules based on the viscosity blending index have been examined. It was found that the prediction accuracy for the crude oil/toluene blends was not satisfactory. Koval, Maxwell, and Almaamari mixing rules showed the best results for predicting the viscosity of blends using kerosene and diesel diluents.

Density, refractive index, and derived properties of binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate

The density and refractive index were experimentally determined for binary mixtures of water + ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate throughout the ionic liquid mass fraction range, at atmospheric pressure and various temperatures between 293.15 K and 323.15 K. The refractive index was measured at five wavelengths between 589.2 nm and 935 nm. From the experimental data on density, volumetric properties such as the excess molar volume and thermal expansion coefficient were calculated. The excess molar volume was negative throughout the ionic liquid mass fraction range and its magnitude decreased with temperature. From the experimental data on the refractive index, the deviation in the refractive index and its coefficients of concentration, temperature and chromatic dispersion were obtained. The values of the deviation in the refractive index were positive and decreased with temperature. In order to simultaneously investigate the dependence of the refractive index on concentration, temperature and wavelength, we correlated the experimental data with a two-term Cauchy equation. Furthermore, a comparative study of 11 refractive index mixing rules was performed to assess their prediction ability. More advanced mixing rules do not lead to any improvement in comparison with the simple linear mixing rule (Arago-Biot) for estimating refractive index and the concentration contrast factor of the mixture studied. The results are expected to be useful for tuning the properties of an ionic liquid by adding water or selecting the temperature or optical region.