Refractive Index Deviations Research Articles

Density, Viscosity, Refractive Index and Excess Properties of Binary and Ternary Solutions of Poly (Ethylene Glycol), Sulfate Salts and Water at 298.15 K

The refractive index (n_D ), viscosity(η) and density (ρ) values of the poly (ethylene glycol) (PEG) 300,400 and 600 + water , zinc sulfate, magnesium sulfate and aluminum sulfate + water binary and their ternary solutions have been measured at 298.15 K and atmospheric pressure. In this work, the effect of concentration (0.05-0.3 %w/w), PEG molecular weight and type of cation on the n_D,η and ρ of the mention binary and ternary mixtures have been explored. Furthermore, the experimental measurements were applied to compute the refractive index deviation (Δn_D), viscosity deviation (Δƞ), the apparent specific volume (V_φ), excess molar volume (V^E) and excess Gibbs energy of activation for viscous flow〖ΔG〗^(≠E)) for the analysis of the behavior of the solutions. Δn_D and V^E were fitted to the Cibulka and a third-order Redlich–Kister polynomial models to estimate the interaction parameters. The intermolecular interactions between the mixing components were demonstrated by the obtained data from the calculated functions.

Volumetric, ultrasonic, viscometric and refractive index studies of molecular interactions in binary mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate with methyl acrylate at temperatures from 293.15 to 318.15 K

In this work the intermolecular interaction of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] and methyl acrylate [MA] were examined from the measurement of physicochemical properties (density, ultrasonic speed, viscosity and refractive index) at temperatures, T/K = 293.15 to 318.15 and atmospheric pressure. The experimental data were used to calculate the excess properties such as excess molar volume, VmE, excess speed of sound, uE, excess molar isentropic compressibility, Ks, mE, deviation in viscosities Δη, and deviation in refractive index, ΔϕnD. In addition, the partial molar volume, (V¯m,1 and V¯m,2) and compressibility (K¯s,m,1 and K¯s,m,2); and excess partial molar volume, (V¯m,1E and V¯m,2E); and compressibility, (K¯s,m,1E and K¯s,m,2E) over the entire composition range; and partial molar volume (V¯m,1° and V¯m,2°); and compressibility (K¯s,m,1° and K¯s,m,2°) and excess partial molar volume (V¯m,1°E and V¯m,2°E) and compressibility (K¯s,m,1°E and K¯s,m,2°E) at infinite dilution have also been calculated. The correlations of these excess properties were made with the Redlich–Kister polynomial equations. From the variations of these parameters with composition and temperature, the results were discussed from the point of intermolecular interactions prevailing in this system. Also, some theoretical mixing rules (Lorentz-Lorenz, Gladstone-Dale, Arago-Biot, Weiner and Eykman) usually used in correlating the refractive indexes were assessed and results were compared with experimental data.

Parallel plications may enhance surface function: physical properties of transparent tunics in colonial ascidians Clavelina cyclus and C. obesa

AbstractAn array of nano-scale protrusions, called the nipple array, is found on the body surface of various invertebrates, and this structure is believed to decrease light reflectance and water wettability on the surface in the terrestrial environment. However, its potential functions have not been well studied in aquatic environments. Clavelina spp. are colonial ascidians that have the nipple array on their integumentary matrix (i.e. tunic). We examined the physical properties on the surface of the tunic of C. cyclus and C. obesa, such as hardness, wettability and refractive indices, to evaluate the functional importance of this structure. The tunic cuticle of both species was covered with the nipple array, and the cuticle of C. cyclus was bent into folds forming parallel plications. The Clavelina tunic was very soft and had high bubble- and oil-repellency. The refractive-index deviation between the tunic and seawater was 0.07–0.095 for 589-nm light (D-line). Rigorous coupled wave analysis (RCWA) showed that the nipple array slightly reduced reflectance on the surface and the parallel plications reduced the reflectance still more. The nanoimprinted plates imitating the parallel plications have higher bubble repellency and lower reflectance than the flat plates. These findings support the functional importance of the plications as well as the nipple array.

Volumetric properties of binary mixtures of 1-ethyl-3-methylimidazolium ethyl phosphonate + methanol or 2-propanol

The present study aimed to determine the refractive indices at 293.15 K and density data at T= (283.15, 293.15, 303.15 and 313.15) K of the binary mixtures of 1-ethyl-3-methylimidazolium ethylphosphonate + methanol or 2-propanol under the atmospheric pressure. The excess molar volume, the apparent molar volume, the partial molar and excess partial molar volumes of the components at infinite dilution were calculated from the experimental values. The results of excess molar volumes were fitted to a Redlich– Kister equation, leading thus to obtain the coefficients and to estimate the standard deviations between the experimental and the calculated quantities. Also, the results of excess molar volumes of the two investigated binary mixtures showed negative deviations from ideal behavior of the investigated binary systems which can be then discussed in terms of ion-dipole interactions, formation of hydrogen bonds and structural factors. Additionally, the refractive indices measurements and the deviations of refractive index were determined.

Effective-Medium Characteristics of Reflective Metasurface: A Quasi-One-Port Network Theory

Reflective metasurfaces are utilized as a bridge linking propagating waves and surface waves. However, the effective constitutive parameters (permittivity and permeability) cannot be retrieved by conventional theory without transmission coefficients. In this paper, an innovative method based on a quasi-one-port network model is proposed to robustly retrieve the effective electromagnetic parameters ( $\varepsilon _{\mathrm {eff}}$ , $\mu _{\mathrm {eff}}$ , $n_{\mathrm {eff}}$ , and $z_{\mathrm {eff}}$ ) for reflective metasurfaces with isotropic unit cells. The validity of the method is demonstrated by imping TE-polarized terahertz waves normally and obliquely (10°) on the multiple-layer unit cells. The effective boundary of the multiple-layer cells is determined by minimizing the deviation of the effective refractive indices from 0.1018 to 0.0260 using a genetic algorithm, which increases the consistency of the retrieval results. The sensitivity of the effective constitutive parameters to the accuracy of reflection coefficients and nonzero incident angle $\theta _{i}$ is also discussed. This method is beneficial for the design of reflective metasurfaces or multichannel reflectors, the coupling of spoof space plasmon polaritons, and other applications of anomalous reflection.

Volumetric, acoustic and viscometric studies of intermolecular interactions in polyethylene glycol 400 + alkyl acrylate binary mixtures at temperatures from 293.15 to 318.15 K

ABSTRACT Densities, ρ, speeds of sound, u and refractive index, n D of binary solutions of polyethylene glycol 400 with methyl acrylate (MA), ethyl acrylate (EA), n-butyl acrylate (n-BA), including those of pure components, have been measured over the whole composition range at temperatures (293.15–318.15) K and atmospheric pressure. From experimental data, excess molar volume, , excess isentropic compressibility, , excess speed of sound, , excess molar isentropic compressibility, , deviations in refractive indices, and deviations in molar refraction, . The partial and excess molar volumes and compressibilities covering the entire mole fraction range, and at infinite dilution were also calculated. These parameters variation with composition and temperature of mixtures suggest the difference in shape and size of molecules of components and formation of hydrogen bonding between unlike molecules. Moreover, the refractive indices of binary solutions are predicted by various empirical mixing rules and compared with experimental findings.

Multiferroic BFO/BTO multilayer structures based magnetic field sensor

Optical properties of polar multifunctional oxides under the influence of magnetic field are of great importance for the materialization of magnetic field sensors and ultrafast optoelectronic devices. Surface plasmon resonance (SPR) technique is an eminently precise means suitable for interface inspection. In this report, an effort has been made to develop an optical magnetic field sensor based on BFO/BTO multilayered thin films prepared using pulsed laser deposition (PLD) technique. The sensing principle relies on SPR phenomenon where the variation in magnetic field has been sensed by examining the variation in optical parameters i.e. reflectance and refractive index. The deviation in refractive index of BFO/BTO multilayered thin films for varying magnetic field has been estimated in order to calibrate the sensor for efficient sensing.

Study of Excess Properties of Binary and Ternary Mixtures of Trichloroethene, Ethanoic Acid, and N,N-Dimethylformamide at Different Temperatures

Density, viscosity and refractive index measurements were performed for ternary mixture of trichloroethene + ethanoic acid + N,N-dimethylformamide and their binary mixtures in the whole composition range. Density data were obtained within the temperature range (293.15 to 303.15) K and viscosity and refractive index data were measured at 298.15 K. Excess molar volumes, viscosity deviations and refractive index deviations were calculated from the experimental data. The values for the ternary mixture and also for the two binary mixtures of trichloroethene (1) + N,N-dimethylformamide (3) and ethanoic acid (2) + N,N-dimethylformamide (3) were negative and became more negative by increasing temperature. For the trichloroethene (1) + ethanoic acid (2) mixture, the values were positive and become more positive with rising temperature. An inverse trend was observed for viscosity deviations of the mixtures. The refractive index deviations were positive for all the mixtures. The experimental data for the binary and ternary mixtures were correlated with Redlich–Kister, and Cibulka equations respectively.

Volumetric and Optical Properties of Dimethylvinylethoxysilane with n-Alkanes (C7 to C10) at Temperatures in the Range (298.15 to 318.15) K

Densities and refractive indices are investigated for four binary mixture systems of dimethylvinylethoxysilane with n-heptane, n-octane, n-nonane and n-decane at different temperatures (298.15, 303.15, 308.15, 313.15 and 318.15 K) and atmospheric pressure. From these experimental data, the excess molar volume, isobaric coefficient of thermal expansion, deviation in refractive index, molar refraction, and deviation in the molar refraction have been calculated. The computed quantities have been fitted with the Redlich–Kister equation to derive the coefficients and estimate the standard deviations. The values of the partial excess volume at infinite dilution were calculated using the coefficients of the Redlich–Kister smoothing equation. The effects of composition and temperature on these properties are discussed.

Molecular interactions in the binary mixtures of some monoalkanolamines with acetonitrile between 303.15 and 323.15

Densities, ρ, and refractive indices, nD for the binary systems of acetonitrile (ACN) + monoethanolamine (MEA), + monomethylethanolamine (MMEA), and + monoethylethanolamine (MEEA) have been measured in the whole range of composition and at different temperatures from T = (303.15 to 323.15) K for ρ, and at T = 303.15 for nD. Excess molar volumes, VmE, partial molar volumes, V¯i, thermal expansivities, α, and excess thermal expansivities, αE, were calculated from the experimental ρ. From measured nD at 303.15 K deviations in refractive index, ΔnD, and excess molar refractions, RmE, for these mixtures have also been evaluated. Values of VmE, αE, and RmE were found to be almost negative within the studied range of temperature. For each system the values of ρ, α, and nD were correlated to appropriate polynomials, whereas those of VmE, αE, ΔnD, and RmE were fitted to the Redlich-Kister type equations. Moreover, temperature dependent Jouyban-Acree model also showed satisfactory correlation with experimental ρ values for all the systems. Though intermolecular interactions of various types are to influence the variation patterns of VmE, V¯i, αE, and RmEvs. composition for these systems, it has been suggested that those due to cross H-bonding and interstitial accommodation effect have to play the significant roles.

Physicochemical and excess properties of binary mixtures of(1-alkyl-3-methylimidazolium bromide+1,2-propanediol/1-propanol) at <italic>T</italic>=(288.15 to 333.15) K

In the present work, the density, ρ , refractive index, n D, and dynamic viscosity, η , for four binary solutions containing ionic liquids [C n mim]Br (C n mim=1-alkyl-3-methylimidazolium, n =6, 8) and 1,2-propanediol (PG)/1-propanol (NPA), at temperatures 288.15– 333.15 K and ambient pressure were investigated. Additionally, the excess molar volume, V mE, and the refractive index deviations, Δ n D, were calculated and correlated using the Redlich-Kister polynomial equation. The density, refractive index, and natural logarithm of dynamic viscosity of the binary mixtures were correlated using empirical equation. The influence of alcohol, ionic liquids, and temperature on the physicochemical properties was discussed.

Physicochemical properties, 1H NMR, ab initio calculations and molecular interactions in a binary mixture of N-methylimidazole with ethyl acetate

For a binary mixture of x N-methylimidazole (hereafter abbreviated as N-mim) + (1 − x) ethyl acetate (hereafter abbreviated as EAC), the density, sound velocity, viscosity and refractive index at (288.15, 298.15, 308.15, 318.15, and 328.15) K, mixing enthalpy at 298.15 K, and 1H NMR measurements combined with the ab initio calculations were carried out over a full molar fraction range.The density, sound velocity, isentropic compressibility, refractive index, viscosity, Gibbs energy of activation of viscous flow and the isobaric thermal expansivity were correlated with a polynomial well. The excess molar volume, excess isobaric thermal expansivity, isobaric thermal expansivity deviation, excess sound velocity, sound velocity deviation, excess isentropic compressibility, isentropic compressibility deviation, excess refractive index, refractive index deviation, excess logarithm viscosity, viscosity deviation, excess Gibbs energy of activation of viscous flow and the molar mixing enthalpy, were calculated and fitted to a Redlich-Kister polynomial. The activation parameters of viscous flow of the mixture, chemical shift changes of N-mim and EAC protons, interaction energy and second-order perturbation stabilization energy of 2-CH···OC, 2-CH···N and CH···O H-bonds were calculated.The mixing process of N-mim with EAC is an endothermic process with volume contraction. The energy to break the like molecular interactions is bigger than that to form dislike molecular interactions, and the volume contraction is mainly attributed to both the free volume difference and the more effective steric accommodation of molecules in the mixture.The 2-CH···OC and 2-CH···N H-bonds are approximately equivalent in dimers, 2-CH···OC H-bond in dimer (N-mim + EAC) is stronger and more stable than the CH···O H-bonds in EAC dimer. The amount of 2-CH···OC H-bond reaches a zenith at x ≈ 0.5. The formation of 2-CH···OC H-bond leads to the electron density rearrangement of the N-mim and EAC molecules, where the electron densities of the N-mim and EAC protons decrease and increase, respectively.

Densities, viscosities, and refractive indices of binary and ternary mixtures of methanol, acetone, and chloroform at temperatures from (298.15–318.15) K and ambient pressure

Densities, viscosities, and refractive indices of binary and ternary liquid systems of methanol, acetone, and chloroform at temperatures from)298.15–318.15(K and ambient pressure were measured. In this regard, it should be stressed that the measurements covered the whole composition range of the components in the binary and the ternary systems. In addition, the experimental data have been utilized in order to extract some derived properties like excess molar volume (VE), viscosity deviation (Δη), and refractive index deviation (ΔnD). To correlate the aforementioned derived properties, the well-known Redlich-Kister and Cibulka equations were applied on the binary and ternary mixtures, respectively. Consequently, the control parameters, as well as the corresponding standard deviations, were completely reported. Moreover, for further validation, the McAllister three-body interaction model for kinematic viscosity and Grunberg-Nissan model for dynamic viscosity were examined and the results were thoroughly compatible with the Redlich-Kister polynomial equation. By using the derived properties, the nature of the intermolecular interactions and the hydrogen bond between solvents in the binary and ternary mixtures were discussed and the results are satisfying in terms of matching to the theoretical models.

Physicochemical Properties, 1H-NMR, Ab Initio Calculations and Molecular Interaction in Binary Mixtures of N-methylimidazole with Methanol

Over the full molar fraction range, the density, viscosity, refractive index, conductivity and pH at the temperatures (298.15, 308.15, and 318.15) K, mixing enthalpy at T = 298.15 K, and 1H-NMR were measured for the binary mixtures of x N-methylimidazole (hereafter abbreviated to N-mim) + (1 − x) methanol, together with ab initio calculations. The thermodynamic parameters of activation for viscous flow were calculated and analyzed. The excess molar volume, viscosity deviation, deviation for the logarithm of viscosity, refractive index deviation and the excess refractive index, excess Gibbs energy of activation of viscous flow and the molar mixing enthalpy were calculated and fitted with a Redlich–Kister equation. The partial molar mixing enthalpies and the protons’ chemical shift changes of N-mim and methanol were calculated and explained. An increase in temperature leads to the excess molar volume becoming more negative, whereas the deviations for the logarithm of viscosity, viscosity deviation and the excess Gibbs energy of activation of viscous flow become less positive; in contrast the refractive index deviation and the excess refractive index become less positive at first and then become more positive. The activation of the viscous fluid is a more ordered process. The physicochemical properties, ab initio calculations, combined with the 1H-NMR results reveal that the molecular interactions among unlike molecules is stronger than that between like ones. There is an ionization process and hydrogen bond interaction between N-mim and methanol, the predominant interaction is N-mim:methanol = 1:1 hydrogen-bonded network, where the methyl groups of methanol and N-mim, respectively, are electron-withdrawing and electron-donating groups.

Thermo physical, optical and spectroscopic perspectives of molecular interactions in binary mixtures of Ethyl Lactate and Dimethyl Adipate at T = 303.15–318.15 K and atmospheric pressure

ABSTRACTMolecular interactions are evaluated in the binaries of Ethyl Lactate and Dimethyl Adipate using experimental values of density, ultrasonic velocity and refractive index over entire composition range as a function of temperature from 303.15 to 318.15 K at atmospheric pressure. Excess thermodynamic properties: excess molar volume, excess isentropic compressibility, excess isothermal compressibility, excess free length, excess isobaric thermal expansion coefficient, excess ultrasonic velocity and refractive index deviations are computed and fitted with Redlich-Kister polynomial equation to obtain the binary coefficients and the standard deviations. The existence of specific interactions in the mixture is revealed by excess properties, and further supported by partial molar properties. FTIR analysis ascertains the dominance of packing effect in the studied mixtures. Prediction of refractive index for the mixtures and pure components is done by several mixing rules with the estimation of relative errors. In addition, data are analysed by the Prigogine–Flory–Patterson theoretical model.

Molecular interaction studies of binary mixture formed by 2-methoxyethanol and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide-based ionic liquid

ABSTRACTPhysicochemical properties such as density (ρ), speed of sound (u) and refractive index (nD) for binary mixture of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide with 2-methoxyethanol (2-ME), have been investigated over the whole composition range at different temperatures (298.15–318.15) K and ambient pressure. Additionally the excess properties such as excess molar volume (), excess molar isentropic compressibility (), excess isobaric thermal expansion coefficient (), deviation in refractive index () and partial molar quantities, have been also evaluated, simultaneously these are fitted with Redlich-Kister type equation for acquiring the binary coefficients and standard deviations. The calculated data has been interpreted in terms of various interactions and structural property between organic and ionic liquid molecules upon mixing. ATR-FTIR studies also carried out to know the microscopic interactions. The experimentally obtained excess molar volumes are further analysed with the help of Prigogine-Flory-Patterson (PFP) theory.

Volumetric and refractive properties of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane with methoxybenzene, chlorobenzene, tert-butylbenzene and nitrobenzene at T = (298.15–318.15) K

In this work, the densities and refractive indices of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane with methoxybenzene, chlorobenzene, tert-butylbenzene and nitrobenzene at different temperatures T = (298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure using a DMA4500/RXA170 combined system were measured. Excess molar volumes, isobaric thermal expansion, molar refractions, and the deviations in refractive indices have been estimated. These parameters have been used to understand the interactions in the mixtures qualitatively. The values of excess molar volume were fitted to Redlich–Kister equation to check the accuracy of experimental data.

Densities, speeds of sound, refractive indices, excess and partial molar properties of polyethylene glycol 200 + methyl acrylate or ethyl acrylate or n-butyl acrylate binary mixtures at temperatures from 293.15 to 318.15 K

The densities, ρ, speeds of sound, u and refractive indices, nD of binary mixtures of polyethylene glycol 200 with methyl acrylate, ethyl acrylate, n-butyl acrylate, including those of pure liquids, over the entire composition range were measured at temperatures (293.15, 298.15, 303.15, 308.15, 313.15 and 318.15) K and atmospheric pressure. Using the experimental data, the excess molar volume, VmE, excess molar isentropic compressibility, Ks, mE, excess speed of sound, uE, deviations in refractive index, ΔϕnD, deviations in molar refraction, ΔRM have been calculated. The partial molar volumes and compressibilities, excess partial molar volumes and compressibilities over the whole composition range, and at infinite dilution have also been calculated. The excess properties were correlated by the Redlich–Kister polynomial equation. The variations of these parameters with composition and temperature are discussed in terms of intermolecular interactions in these mixtures. Moreover, the values of ultrasonic speeds for these mixtures were also calculated by using scaled particle theory and the results are compared with the experimentally measured values.

Densities, speeds of sound, refractive indices, viscosities and their related thermodynamic properties for n-hexadecane + two aromatic hydrocarbons binary mixtures at temperatures from 298.15 K to 318.15 K

Abstract The thermophysical properties (density, speed of sound, viscosity and refractive index) for the binary mixtures of n-hexadecane with n-propylbenzene and sec-butylbenzene, were measured at temperatures in the range of (298.15–318.15) K and pressure of 0.1 MPa. The obtained experimental results were used to calculate the excess and deviation quantities, namely the excess molar volumes, the excess speed of sound, the excess isentropic compressibilities, excess molar isentropic compressibility, the deviation in viscosities, the deviation in refractive indices, and the excess molar refractions. The correlation of these excess properties was made by help of the Redlich-Kister type polynomial expression. The experimental viscosity values were compared with those calculated by using several different equations: Grunberg–Nissan, Katti Chaudry, Hind, Dolezalek, and three-body McAllister interaction model. Some theoretical (n,ρ) mixing rules (Lorentz-Lorenz, Gladstone-Dale, Arago-Biot, Edwards and Eykman) usually used in predicting the refractive indexes were assessed. The experimental and calculated results are discussed from the point of view of the molecular interactions between components of mixtures and their structural effects.

Viscosity, Gibbs Free Energy, and Refractive Indices for Binary Mixtures of o-Cresol + Poly(ethylene glycols) at T = 288.15–308.15 K and 96.5 kPa

The viscosities (η) and refractive indices (nD) were measured for the binary mixtures of o-cresol + PEG 200/PEG 300/PEG 400 over the whole composition range at five different temperatures (288.15, 293.15, 298.15, 303.15, and 308.15 K). From the experimental results, the viscosity deviation (Δη), the excess Gibbs free energy of activation of viscous flow (ΔG*E), the deviation in refractive index (ΔϕnD), and the molar refraction (Rm) have been calculated. The excess or deviation properties were fitted with Redlich–Kister polynomial equation and their coefficients and standard deviations were calculated. The positive and negative excess or deviation properties were discussed in terms of specific molecular interactions between mixture components. The excess or deviation property values (Δη, ΔG*E, and ΔϕnD) follow the order PEG400 > PEG300 > PEG200. On the basis of the viscosity data, Gibbs energies of viscous flow (ΔG*), enthalpy of activation of viscous flow (ΔH*), and entropy of activation of viscous flow (ΔS*) were also calculated.