Refractive Index Deviations Research Articles

Sensitivity of backscattering to spherical particle physical properties: Size, refractive index, and shape deviations

The purpose of this paper is to study the dependency of light backscattering on particle physical properties: size, refractive index, and shape; and to demonstrate the extreme sensitivity of backscattering on these properties. We demonstrate how the nondescript backscattering pattern evolves seemingly chaotic, in contrast to the orderly forward scattering, with the particle's physical properties. The demonstration was carried out by light scattering from water droplets and with spherical particle Mie theory. Our results show systematic, descriptive evolution of the forward scattering pattern, which is clearly shown in logarithmic Q–space, whereas non-descriptive, chaotic evolution within the backscattering regime is displayed in linear θ–space. Additionally, our study shows that within the last 1°, the backscattering intensity remains constant and featureless for the ∼ 2.5 μm diameter water droplets investigated here.

Experimental and computational insight in molecular interactions of imidazolium based deep eutectic solvent with selected alcohols (C1 and C2)

The experimental thermophysical properties (densities (ρ), speed of sound (u) and refractive (nD) indices) of binary mixtures containing 1:3 mol ratio of [1-butyl-3-dimethylimidazolium chloride to ethylene glycol] [BMIM]Cl: EG], deep eutectic solvent (DES), with selected alcohols (methanol and ethanol) were measured. The measurements of the binary mixtures and the pure solvents were conducted at temperatures ranging from (293.15 to 313.15) K in the interval of 5 K and at ambient pressure using an Anton Paar densitometer. Thermodynamic properties such as excess molar volumes (VmE), intermolecular free length (Lf), isentropic compressibilities (ks), deviation in isentropic compressibilities (Δks) and deviation in refractive indices (ΔnD) were computed from the measured data of physical properties. These excess thermodynamic properties are utilized to investigate the intermolecular interactions occurring between imidazolium DES and methanol or ethanol. Geometry optimization calculations were undertaken using Density Functional Theory (DFT) to model the structure of DES with a 1:1 mol ratio employing the B3LYP-D3 functional and a basis set of 6–31G++**. The DFT results revealed that the interaction energies within the DES in the presence of solvent favoured the formation of the complex. Furthermore, interrogation of the optimized structures at molecular level showed that the interactions were mediated by the electrostatic ionic bonding with the co-solvent playing a significant role in solubility. The excess molar volumes of binary mixtures were correlated using the Lorentz-Lorenz equation, and the densities and refractive indices were predicted using the Lorentz-Lorenz equation. The interaction energies and electrostatic interactions between the different solvents were predicted using quantum mechanics. The experimental data was found to be in good agreement with the theoretical data for the measured properties as well as the computational predictions of the stability of the systems.

The study of thermodynamic properties of diethylene glycol monoethyl ether with 2-alkanols (C3 − C7) with use of PFP and ERAS modeling

Thermodynamic properties like excess volume VmE, excess partial volume V¯m,iE, in isentropic compressibility deviations Δ Ks, and refractive index deviations ΔnD, have been calculated based on experimental density ρ, speed of sound u, and refractive index nD, by an Anton Paar / DSA 5000/ densimeter and Anton Paar Abbemat / 500/ refractometer. The systems of diethylene glycol monoethyl ether (DEGEE) + 2-propanol, or + 2-butanol, or + 2-pentanol, or + 2-hexanol, or + 2-heptanol, were given at T = (298.15–318.15) in 10 K intervals at ambient pressure (81.5 kPa) have been investigated. Data was fitted by Redlich-Kister relation.TheVmE is negative for + 2-propanol and positive sign for other systems observed. The Δ Ks is negative for all systems, except for + 2-heptanol system is positive. The ΔnD is negative for + 2-hexanol or + 2-heptanol systems and is positive for all the rest. The The intermolecular interactions and structure factors were discussed for the binary mixtures. In addition the Prigogine–Flory–Patterson theory (PFP) and Extended Real Associated Solutions (ERAS) models were used to correlate VmE data of binary mixtures. The fitting data for all systems reasonable consistency with experimental data for all the systems.

Measurement Error Analysis of Seawater Refractive Index: A Measurement Sensor Based on a Position-Sensitive Detector.

The seawater refractive index is an essential parameter in ocean observation, making its high-precision measurement necessary. This can be effectively achieved using a position-sensitive detector-based measurement system. However, in the actual measurement process, the impact of the jitter signal measurement error on the results cannot be ignored. In this study, we theoretically analysed the causes of long jitter signals during seawater refractive index measurements and quantified the influencing factors. Through this analysis, it can be seen that the angle between the two windows in the seawater refractive index measurement area caused a large error in the results, which could be effectively reduced by controlling the angle to within 2.06°. At the same time, the factors affecting the position-sensitive detector's measurement accuracy were analysed, with changes to the background light, the photosensitive surface's size, and the working environment's temperature leading to its reduction. To address the above factors, we first added a 0.9 nm bandwidth, narrow-band filter in front of the detector's photosensitive surface during system construction to filter out any light other than that from the signal light source. To ensure the seawater refractive index's measuring range, a position-sensitive detector with a photosensitive surface size of 4 mm × 4 mm was selected; whereas, to reduce the working environment's temperature variation, we partitioned the measurement system. To validate the testing error range of the optimised test system, standard seawater samples were measured under the same conditions, showing a reduction in the measurement system's jitter signal from 0.0022 mm to 0.0011 mm, before and after optimisation, respectively, as well as a reduction in the refractive index's deviation. The experimental results show that the refractive index of seawater was effectively reduced by adjusting the measurement system's optical path and structure.

The thermodynamic behavior of binary systems isoamyl acetate and alcohol through experimental measurements and modeling

The thermodynamic and transport properties are experimentally determined for three binary liquid mixtures consisting of isoamyl acetate and different alcohols at ambient pressure and in temperature range. From measured density, viscosity and refractive index are calculated excess molar volume, viscosity and refractive index deviations. Isentropic compressibility and excess molar Gibbs free energies of viscous flow are determined combining density with speed of sound and viscosity data. All mentioned derived properties are used to analyze the changes taking place in investigated binary systems causing deviations from the ideal mixture. Additionally, partial molar volumes and excess partial molar volumes, as well as thermal expansion coefficient, were calculated. The results are discussed in terms of chemical structure of used compounds and the influence of the alcohol present in the mixture on the mixture behavior. The study showed that higher influence has branching of the alcohol molecule and position of the –OH group rather than the length of the primary alcohol chain. Beside the experimental part, the modeling of the excess molar volume and viscosity was also performed, and the percentage deviations are used as the indicator of model performance in terms of model approach, predictive or correlative, and number of model parameters, one to three parameters optimized.

Experimental and theoretical studies to investigate molecular interactions between ethylene glycol oligomers and 1-butyl-3-methylimidazolium bromide

The thermophysical characteristics of pure liquids and their mixes are substantial in applied as well as theoretical research. This paper presents the measured data on: density (ρ), viscosity (η), refractive index (nD) and consequent calculated parameters: {excess molar volume (VmE), partial molar volume (V¯m), excess partial molar volume (V¯mE), deviation in viscosity (Δη), excess Gibbs energy of activation of viscous flow (ΔG∗E), deviation in refractive index (ΔϕnD) and deviation in molar refraction (ΔxRM)} of binaries containing 1-butyl-3-methylimidazolium bromide ([BMIM]Br) with glycol oligomers (mono/di/tri/tetra-ethylene glycol) at T/K = 298.15–313.15 and pressure p/MPa = 0.1. The Redlich-Kister equation efficiently estimates the standard deviation between the experimental and calculated excess properties. The interactions between constituents were considered while interpreting the obtained results. The values of VmE, V¯mE, Δη, ΔϕnD and ΔxRM exhibited negative trends throughout the range, whereas ΔG∗E values displayed a sigmoidal shift (negative to positive) with increasing [BMIM]Br concentration. The VmE data has been explored in terms of Prigogine-Flory-Patterson (PFP) and Graph theories to elucidate the deviations in thermophysical properties of the mixtures caused by variations in strength and magnitude of interactions. Additionally, the η values were correlated using ten models and their correlation ability has been perceived via the average standard deviation percentage. The pure and binary mixtures were also spectroscopically examined using Fourier Transform InfraRed (FT-IR) and Raman spectroscopy to elucidate the structural variations.

High-Sensitivity Seawater Refraction Index Optical Measurement Sensor Based on a Position-Sensitive Detector.

The refractive index of seawater is one of the essential parameters in ocean observation, so it is necessary to achieve high-precision seawater refractive index measurements. In this paper, we propose a method for measuring the refractive index of seawater, based on a position-sensitive detector (PSD). A theoretical model was established to depict the correlation between laser spot displacement and refractive index change, utilizing a combination of a position-sensitive detector and laser beam deflection principles. Based on this optical measurement method, a seawater refractive index measurement system was established. To effectively enhance the sensitivity of refractive index detection, a focusing lens was incorporated into the optical path of the measuring system, and simulations were conducted to investigate the impact of focal length on refractive index sensitivity. The calibration experiment of the measuring system was performed based on the relationship between the refractive index of seawater and underwater pressure (depth). By measuring laser spot displacement at different depths, changes in displacement, with respect to both refractive index and depth, were determined. The experimental results demonstrate that the system exhibits a sensitivity of 9.93×10-9 RIU (refractive index unit), and the refractive index deviation due to stability is calculated as ±7.54×10-9 RIU. Therefore, the feasibility of this highly sensitive measurement of seawater refractive index is verified. Since the sensitivity of the refractive index measurement of this measurement system is higher than the refractive index change caused by the wake of underwater vehicles, it can also be used in various applications for underwater vehicle wake measurement, as well as seawater refractive index measurement, such as the motion state monitoring of underwater navigation targets such as AUVs and ROVs.

Studies on thermodynamics properties of binary mixtures of amyl acetate with propanol at T = 298.15 K to 318.15 K

The thermophysical properties of amyl acetate and isomers of propanol are critical for a variety of industrial, scientific, and safety–related applications. The density (ρ), viscosity (η), speed of sound (u), and refractive index (nD) of binary amyl acetate (1) + propanol (2) mixtures were measured at T = 298.15 K–318.15 K and pressure of 0.1 MPa. The excess molar volume (VmE), deviation in viscosity (Δη), deviation in speed of sound (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were derived from measured data. The deviation parameters in binary mixtures are affected by H–bonding, interstitial accommodation, and dipole–dipole interactions. The VmE, Δη and κsE values were described with Graph theory, Prigogine-Flory-Patterson (PFP) theory, Singh model, and ab–initio approach. While the VmE and Δη rise with increment in temperature whereas Δu and ΔnD decrease with increase in temperature.

Modeling the Impact of Dye Concentration on Polymer Optical Properties via the Complex Refractive Index: A Pathway to Optical Engineering.

This work investigates the potential to rely on the complex refractive index to correlate the chemical composition of polymers with their optical properties, including transmittance, reflectance and absorbance. The optical properties of polycarbonate slabs with various controlled concentrations of two dyes were initially measured and analyzed. The reflection and transmission measurements obtained were used to determine the corresponding complex refractive index over a wide range of wavelengths. Comparing it with that of a clear material provided the spectral deviation of the complex refractive index induced by the dye concentrations and resulted in assigning a spectral efficiency to both of them. A modification function of the complex refractive index was established based on this spectral efficiency, which acts as a spectral fingerprint related to each dye. Finally, two samples doped with the two dyes mixed were studied to assess the model's capabilities. On the one hand, based on the measured transmittance, the dye concentrations were determined within a deviation below 8% in comparison with the values provided by the manufacturer. On the other hand, when the dye concentrations were known, the model reproduced the optical properties with good accuracy beyond the limitations of the experimental setup. The model's effectiveness in correlating the chemical composition of polymer with its optical properties through the complex refractive index makes it a valuable asset in analyzing and formulating plastics with intended optical properties.

Physicochemical properties, theoretical modelling and molecular interaction analysis in ternary liquid mixtures containing 1-propanol, 1,3-diaminopropane and ethyl acetate at temperature 298.15–318.15 K

In the present report, density (ρ), viscosity (η), speed of sound (u) and refractive index (nD) of ternary liquid mixture containing 1-propanol (1P) (1) + 1,3-diaminopropane (1,3-DAP) (2) + ethyl acetate (EAc) (3) were measured at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. Data of ρ, η, u and nD were used to compute the excess molar volume, VmE, deviation in viscosity, Δη, deviation in ultrasonic speed, Δu, excess isentropic compressibility, ksE, excess free volume, VfE, excess intermolecular free length, LfE, excess available volume, VaE, and deviation in refractive index, ΔnD, and these computed physicochemical properties were fitted to Singh equation. The VmE data were fitted to the Nagata and Cibulka equations. Further, Kohler model, Tsao-Smith model, Radojkovic model, Jacob-Fitzner model and Rastogi model were used to calculate the VmE values. The speed of sound data was analyzed by various correlations such as Van Dael, Nomato, Impedance dependence, Schaaff’s collision factor theory (CFT) and Jacobson’s free length theory (JFLT). Various correlations like Heller, Arago-Biot, Lorentz-Lorenz, Erying, Newton, Gladstone-Dale, and Weiner were used to correlate nD data.

Densities, viscosities, and refractive indices of binary mixtures of tri-n-butyl phosphate with propan-2-ol and butan-2-ol at 303.15, 308.15, 313.15, 318.15, and 323.15 K

Densities, viscosities, and refractive indices of binary liquid mixtures of tri-n-butyl phosphate (TBP) with propan-2-ol and butan-2-ol at different temperatures between 303.15 and 323.15 K at an interval of 5 K and across the entire range of composition were measured. The data were used to calculate derived properties, such as excess molar volumes, excess thermal expansivities, deviations in viscosities, excess free energies of activation for viscous flow, and deviations in refractive index. The variation patterns of these properties concerning composition and temperature for the propan-2-ol + and butan-2-ol + TBP systems were discussed and attributed to probable intermolecular hydrogen bonding and geometric effects. Notably, the influence of hydrogen bonding was substantial, as evidenced by trends in excess molar volumes and deviations in viscosities. Concentration-dependent polynomial equations were used to fit the measured data of density, viscosity, and refractive index, while Redlich-Kister-type equations were applied for the excess properties. The densities and viscosities were correlated using the Jouyban-Acree model. The correlating abilities of various models, such as Grunberg-Nissan, Tamura-Kurata, Heric, Ausländer, McAllister-3, and McAllister-4 body models, were also evaluated using the viscosity data. Additionally, six new pairs of UNIFAC-VISCO group interaction parameters were computed to predict viscosities of TBP in systems involving alkanes, aromatics, and alcohols, extending the application range of the group contribution model.

Volumetric, acoustic, and optical properties of binary mixtures of diethyl ether with alkanol at T = 293.15 K to 303.15 K

Density (ρ), ultrasonic speed (u), and refractive index (nD) of binary liquid mixtures such as diethyl ether (DEE) (1) + alkanol (isomers of propanol and 1-butanol) (2) were experimentally measured at T = 293.15 K to 303.15 K and at 0.1 MPa pressure. By using these measurements excess molar volume (VmE), deviation in ultrasonic speed (Δu), excess isentropic compressibility (κsE), and deviation in refractive index (ΔnD) were computed and associated with the Redlich-Kister polynomial equation. It was found that deviation parameters are influenced by H–bonding, interstitial accommodation, and dipole–dipole molecular interactions between binary mixtures. The VmE values have been interpreted by the Prigogine–Flory–Patterson (PFP) theory and the Flory–Treszczanowicz–Benson (FTB) model. The FTB model and PFP theory anticipated the VmE curves and were able to depict the perfect shape and magnitude of VmE values. The numeric values of u and nD were computed by using several empirical correlations and mixing rules. This study discusses the comparative significance of these relationships with the measured values of u and nD.

Experimental analysis of volumetric, acoustic, viscometric and optical properties of water with 1-amino-2-propanol, 1,2-diaminopropane and 1,3-diaminopropane at T=298.15 -318.15 K: Molecular Modelling by Graph, PFP and IR spectroscopy investigations

BackgroundLiquid mixtures are used as a solvent in most of the natural systems and chemical processes. Therefore, the physicochemical properties of liquid mixtures at different compositions and at different temperatures have a significant role in the optimization of chemical processes. The present report involves the analysis of the thermophysical properties of water (1) and amines (2). MethodsDensity, ρ, dynamic viscosity, η, refractive index, nD, and speed of sound, u, data were measured for binary mixtures of water (1) and amines (1A2P (1-amino-2-propanol), 1,2-DAP (1,2-diaminopropane) and 1,3-DAP (1,3-diaminopropane) (2) at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. Based on experimental data, the excess molar volume, VmE, deviation in dynamic viscosity, Δη, excess Gibbs free energy of activation, G*E, deviation in refractive index, ΔnD, excess ultrasonic speed, uE, excess isentropic compressibility, KsE, deviation in free volume, ΔVf, excess available volume, VaE, and excess intermolecular free length, LfE, were calculated and these evaluated properties were fitted to Redlich-Kister polynomial (R.K.). The VmE data was analyzed by Prigogine-Flory-Patterson (PFP) theory. The dynamic viscosity, η, values were studied by different correlations. The VmE and Δη data were also analyzed by Graph theoretical approach (GTA). Raman and FT-IR spectroscopic studies give important information about the intermolecular interactions present between unlike molecules water (1) and amines (2) which is also recognized by GTA. Significant findingsThe value of VmE and KsE values were found negative over the whole composition range, and it follow the sequence as: 1,2-DAP > 1,3-DAP > 1A2P with water at equimolar composition. GTA and PFP well supported the VmE data. GTA studies help in investigating the specific intermolecular interactions between unlike components. Further, Graph theory studies predicted OH—–NH interaction is dominant interaction among all interactions which were also supported by Raman and FTIR spectroscopic studies.

Focusing performances of high numerical aperture Fresnel zone plates under different immersion media

The focusing performances of high-numerical-aperture (NA) Fresnel zone plates (FZP) under different immersion media are investigated by combining the vectorial angular spectrum (VAS) theory and the finite-difference time-domain method. It has been found that as the refractive index deviation increases, the focus approximately linearly shifts along the positive z-axis. Simultaneously, the transverse size of the focusing spot gradually decreases, and super-resolution focusing is realized. However, the peak intensity declines with an increase in the refractive index. In addition, when the deviation of the refractive index of the actual immersion medium from the design value is less than about 30%, VAS theory can correctly estimate the focusing light field distribution, except when the FZP has only one or two transparent annuli. On the contrary, VAS theory cannot achieve an accurate prediction when the deviation is larger. These findings will benefit the practical application of high-NA FZPs.

Thermophysical properties of binary mixtures of diethyl ether as oxygenate with cyclohexane and aromatic hydrocarbons

Density (ρ), speed of sound (u), and refractive index (nD) were measured for the binary mixture of diethyl ether (1) + cyclohexane, benzene, and toluene (2) systems at T= (288.15 K to 298.15 K) and 0.1 MPa. The measured data were utilized to calculate excess molar volume (VmE), deviation in ultrasonic speed (Δu), and deviation in refractive index (ΔnD). Our results illustrate that the positive value of VmE and negative value of Δu for diethyl ether + cyclohexane indicate the absence of specific interaction owing to the inert nature of cyclohexane and disruption of the dipole–dipole interactions in diethyl ether during mixing. Conversely, in diethyl ether + benzene or toluene system, the negative values of VmE and positive values of Δu suggest the presence of electron donor–acceptor interactions between the oxygen atom of diethyl ether and the π- electrons of benzene and toluene. These findings were further corroborated by the behavior of the molecular association parameter (MA), which showed that toluene exhibited the greatest value of MA and lower value of VmE compared to benzene, indicating a stronger degree of molecular association due increase in π-electron density because of the presence of electron-donating methyl group in toluene. On the other hand, cyclohexane showed the lowest value of MA, suggesting the disruption of dipole–dipole interaction in diethyl ether. Schaff’s collision factor theory demonstrated high predictive power for ultrasonic speed compared to other models. These experimental data significantly impact advancing theoretical models, process design, material development in chemical industries, and our understanding of the basic behavior of mixtures across various scientific and technical domains.

Thermodynamics of ternary mixtures of oxygenated fuel: Diisopropyl ether + ethanol + n-octane

Depleting conventional fossil fuels and growing greenhouse gases have fascinated the researcher’s heed for the use of green and clean fuels. Thereby, such fuels can be obtained by blending gasoline with the oxygenated fuel additives to reduce the toxic gaseous emissions and enhance the fuel efficiency in the motor engine. In this regard, various thermodynamic properties like densities (ρ), speeds of sound (u) and refractive indices (nD) of the ternary mixture of diisopropyl ether (1) + ethanol (2) + n-octane (3) were experimentally measured at different temperatures (298.15 K to 318.15 K) and at 0.1 MPa. The excess molar volume (VmE), deviation in sound speed (Δu), excess isentropic compressibility (κsE), excess available volume (VaE), excess free length (LfE) and refractive index deviation were evaluated using their corresponding experimental data. Different correlations and analytical rules have been used for conceptual assessment of speed of sound and refractive index of mixtures. The effect of temperature on the above stated thermodynamics properties has also been investigated.

Transport and optical properties of the binary liquid mixture containing 1,3-diaminopropane and alkyl acetates (C1-C4) at T= (303.15-318.15) K: experimental investigations and theoretical modelling

ABSTRACT Physicochemical properties of pure liquids and their liquid mixtures at different compositions and at different temperatures have a significant role in the optimisation of chemical processes. Present report involves the analysis of the physicochemical properties of 1,3-diaminopropane and alkyl acetate. The viscosity () and refractive index () of 1,3-Diaminopropane, 1,3-DAP (1), with alkyl acetates, AAc, (C1-C4) (2) were measured at different temperatures (T = 303.15 to 318.15 K) under the atmospheric pressure 0.1 MPa. Deviation in viscosity, , deviation in refractive index, , and excess Gibbs free energy of activation, for these binary mixtures were calculated from measured viscosity and refractive index data and fitted to Redlich-Kister polynomial equation (R.K.). The data were analysed in terms of the Graph theoretical approach (GTA) to study the interactions in binary mixtures. The values were also correlated by using Bloomfield and Dewan (BFD) model and various correlations. data were correlated by various relevant correlations.

Viscometric and refractive index study of intermolecular interaction between binary mixtures of terpinolene with o-, m- and p-cresol at 303.15, 308.15 and 313.15 K

Viscosities and refractive indexes  were experimentally measured for binary mixtures of terpinolene with o-, m- and p-cresol for entire composition range at 303.15, 308.15 and 313.15 K and at atmospheric pressure. Deviation in viscosity , excess Gibbs energy of activation for viscous flow , enthalpy  and entropy  of viscous flow, deviation in refractive index , molar refraction  and deviation in molar refraction  were also calculated. Various theoretical viscosity relations such as Dolezalek-Schulze ( , Grunberg-Nissan , Tamura-Kurata  Katti-Chaudhri ( , McAllister relation (  and ), Kendall-Munroe relation, Bingham relation and Arrhenius-Eyring relation were calculated. Similarly, nine theoretical refractive index relations such as Arago-Biot (A-B), Dale-Glastone (D-G), Lorentz-Lorentz (L-L), Eykman (Eyk), Weiner (WR), Heller (Hr), Newton (Nw), Oster (Os) and Eyring-John (E-J) were also calculated with their standard deviation  values. Results were discussed in terms of the presence of intermolecular interactions between the components of binary mixtures.

Volumetric, Acoustic, and Refractive Behavior of Acid Gas Absorbers: N-Vinyl-2-pyrrolidinone and Glycol Ethers (2-(2-Ethoxyethoxy)ethanol, 2-(2-Butoxyethoxy)ethanol, and 2-(2-(2-Methoxyethoxy)ethoxy)ethanol)

Thermophysical properties such as density (ρ), speed of sound (u), and refractive index (nD) for pure N-vinyl-2-pyrrolidinone (NVP) and binary mixtures of NVP with 2-(2-ethoxyethoxy)ethanol (DEGMEE), 2-(2-butoxyethoxy)ethanol (DEGMBE), and 2-(2-(2-ethoxyethoxy)ethoxy)ethanol (TEGMME) have been measured over the whole range of mole fraction from temperature T = (298.15 to 323.15) K and at 0.1 MPa pressure employing an Anton Paar vibrating U-tube density and sound velocity meter (DSA 5000 M) and an Abbemat refractometer, respectively. To quantify the nonideality in these systems, the experimental data has been used to evaluate various acoustical and thermodynamic parameters, such as excess molar volume (VmE), deviation in the speed of sound (Δu), isentropic compressibility (κs), excess isentropic compressibility (κsE), deviation in refractive index (ΔnD), molar refraction (Rm), and polarizability (α). Molecular interactions prevailing in these systems have been explained in terms of variation in the measured and calculated values of physicochemical parameters. The collected thermophysical data can be employed in the optimization and design of a desulfurization/CO2-capture process utilizing the studied solutions. Furthermore, this data can also be utilized for the theoretical model extension as well as in solving many difficult engineering problems such as fluid flow, heat and mass transfer, and energy transformations.

Dielectric, refractometric, and volumetric studies on mixing behavior of two structurally related ketones and glycols systems

The dielectric, refractometric, and volumetric properties were systematically investigated for eight binary systems containing two structurally related ketones (methyl isobutyl ketone and mesityl oxide) and four glycols over the entire composition range at 298.15 and 101 kPa. The selected glycols were (1,3-butylene glycol, pentamethylene glycol, diethylene glycol, and triethylene glycol). The experimental data were analyzed using different approaches in terms of intermolecular interactions between the constituent molecules through excess parameters of different physical quantities. The excess parameters confirm the formation of multimer structure during the mixing process. In addition, the refractive index deviations were calculated in terms of volume fraction. Based on the Iglesias-Reis approach, the influence of the interactions in excess Helmholtz energy and excess permittivity from total interactions follow the same order 1,3BG > DE > PG > TEG for their mixtures with the ketones. All the excess Kirkwood correlation factors (giE) are negative but very small for the mixtures. Thus, the Kirkwood correlation factors for binary mixtures (g12) are not very far from the ideal behavior, and therefore, the dipoles preferentially oriented parallel interrupted for some extent by the mixing process. The Redlich–Kister type polynomial equation was used to fit the experimental excess parameters.