Molar Refractive Index Research Articles

Mössbauer spectroscopy and other structural properties of some V2O5.SrO.FeO glasses

ABSTRACT A series of (80-x)%V2O5·(x)%SrO·20%FeO glasses with 0 ≤ x ≤ 40 mole are prepared. The XRD proved the amorphous network of the glasses. Some isolated V = O vanadyl groups and some V–O–V bonds are broken by the Sr ions to form V–O–Sr bridges. A continuous increase in the Tg, Tc, Tm with increasing the mol%SrO is observed . High QS, IS and LW values are detected by Mössbauer spectroscopy. Most iron ions in the samples 0 and 5 mol% SrO appeared in paramagnetic glassy phase. All the iron ions in the glasses containing from 10 to 40 mole% SrO are dissolved in glass network. An increase in the density from 3.2 to 4.2 g.cm3 with a continuous decrease in the molar volume are found with increasing the SrO%. Molar polarisability, molar refractive index in addition to some structural and optical properties are calculated and discussed.

QSPR Models for the Molar Refraction, Polarizability and Refractive Index of Aliphatic Carboxylic Acids Using the ZEP Topological Index

The molar refraction, polarizability, and refractive index for a series of monocarboxylic, dicarboxylic, and unsaturated monocarboxylic acids, having a symmetric or asymmetric structure, were investigated by the application of quantitative structure property relationship (QSPR) technique. We used a linear regression method and a single molecular descriptor, the ZEP topological index, calculated in a simple manner, with the help of weighted electronic distances, and also calculated on the basis of the chemical structure of the molecules. The high-quality performance and predictive ability of the QSPR models obtained were validated by means of specific validation techniques: y-randomization test, the leave-one-out cross validation procedure, and external validation. The investigated properties are well modeled (with r2 > 0.99) by the ZEP index, using the regression analysis as a statistical tool for developing reliable QSPR models. Our approach provides an alternative technique to the existing additive methods for predicting the molar refraction and polarizability of carboxylic acids, which is essentially based on the summation of atom and/or functional group contributions or bond contributions, and of some correction increments.

Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

Molar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

Excess molar enthalpies, excess molar volumes and refractive index of binary liquids mixtures of 2,2′-aminodiethanol with propan-2-ol, butan-1-ol and butan-2-ol at various temperatures and ambient pressure (81.5 kPa)

Excess molar enthalpies, HmE , excess molar volumes, VmE , and refractive index deviations, ΔnD , over the whole composition range have been determined for binary liquid mixtures of 2,2′-aminodiethanol (DEA) + propan-2-ol, or + butan-1-ol, or + butan-2-ol at, T = (303.15) K for excess molar enthalpy, T = (303.15 to 343.15) K for excess molar volume, T = (298.15) K for refractive index and at ambient pressure (81.5 kPa).All the HmE values were positive, indicating that interactions between like molecules are stronger than unlike molecules. All the VmE values were negative, show that the total volume of the mixture before mixing is higher than the total volume of mixture after mixing. Refractive index deviations values were positive; represent mixture after mixing is denser than pure components. Excess or derived properties have been correlated using the Redlich–Kister polynomial equation. The obtained results were qualitatively interpreted in terms of steric hindrance and molecular interactions between the mixing components.

Effect of Pb/B ion replacement in B2O3.PbO.Fe2O3.Na2O glasses: Optical, magnetic, and fluorescence properties

Abstract Glasses of the formula (70-x) %B2O3. x%PbO.10%Fe2O3.20%Na2O are prepared by the melt quenching technique. Complete amorphous structure is confirmed for the XRD checked glasses. Molar polarizability, optical basicity and refractive index are found to decrease with increasing the mol% of PbO in the glasses. Single bond strength and interaction parameters suggest the transfer from covalent to ionic nature with the increase of the mol% of PbO in the glasses. The increase of the polarizability values of the studied glasses leads to a high optical nonlinear properties of the glasses. Metallization criterion is found to increase from 0.37 to 0.53 with increasing the mol% of PbO. Continuous addition of PbO is found to control the paramagnetic character of the glasses. The absorption and emission characteristics are studied. The system band gap and absorption intensity are found to be tunable. Also, it is found that the glass system under investigation experiences fluorescence characteristics with green color.

Synthesis and Biological Evaluation of Amino Acid Based Mutual Amide Prodrugs of Phenytoin as Anticonvulsant Agents.

Phenytoin (5,5-diphenyl hydantoin) has poor water solubility, which results in incomplete oral availability. Other problems associated with the oral and intramuscular administration of phenytoin are gastric irritation and inflammation at the site of injection. The purpose of this study was to synthesize mutual amide prodrugs of phenytoin by using amino acids like glycine, L-tryptophan, L-lysine and taurine. These prodrugs were synthesized and characterized by Fourier Transform Infrared (FTIR), Proton nuclear magnetic resonance (1H NMR) and Mass Spectra. Physical and spectral characterization was performed by determination of solubility, maximum wavelength, partition coefficient (log P), ionization constant (pKa), specific (α) and molar rotation (μ), refractive index (n), specific refraction (RS) and molar refraction (RM). The results obtained from solubility and log P values determination indicated that phenytoin prodrugs can be administered by oral as well as a parenteral route by minimizing the limitations associated with phenytoin. Anticonvulsant activity of prodrugs (4a-4d) was evaluated by using maximal electroshock (MES) and strychnine induced seizure test on albino mice of either sex weighing 25-30 g in which 4b and 4d were found to have significant anticonvulsant activity for MES and strychnine induced seizure test. In vitro enzymatic hydrolysis study of 4b and 4d was performed on liver, intestinal mucosa and plasma sample of male Sprague Dawley rats weighing 280-300 g in which phenytoin was eluted at 10.13 to 10.68 minutes at 220 nm. The results obtained from the present work showed that amino acid-based mutual prodrug strategy can be a promising method to increase the solubility and anticonvulsant activity of phenytoin for the development of anticonvulsant agents.

Experimental Measurement of Physical, Transport, and Optical Properties of Binary Mixtures of N-Hexyl Pyridinium Nitrate [HPy][NO3] Ionic Liquid with Water, Ethanol, and Acetonitrile at 298.15 K and 101 kPa

We have conducted the first investigation of the thermophysical and transport properties of N-hexyl pyridinium nitrate [HPy][NO3], a room-temperature ionic liquid, in combination with water and the organic solvents, ethanol, and acetonitrile in the form of binary mixtures, at 298.15 K and 101 kPa. The densities, viscosities, and refractive indices of the binary mixtures were measured, and the experimental values were used to calculate the derived properties. To examine the volumetric properties of the binary mixtures, the apparent molar volumes were calculated from experimental densities and correlated using both the Redlich–Mayer and Pitzer models. It was found that the dielectric constant and polarity of the solvents had significant effects on the ion–solvent interactions. The viscosities and refractive indices of the mixtures are reported; the B-coefficient of the Jones–Dole equation, and the molar refractive indices determined using the Lorentz–Lorenz equation were calculated. Values of the standard deviations between the calculated and experimental data were determined using the linear least-squares method. Finally, the results were used to shed light on the structure making/breaking effect of ions in the binary mixtures.

Modeling of the Refractive Index for the Systems MX+H2O, M2X+H2O, H3BO3+MX+H2O, and H3BO3+M2X+H2O. M = K+, Na+, or Li+ and X = Cl− or SO42−

The modeling of the refractive index for binary aqueous solutions of boric acid, sodium chloride, potassium chloride, sodium sulfate, lithium sulfate, and potassium sulfate, as well as ternary aqueous solutions of boric acid in the presence of sodium sulfate, lithium sulfate, or potassium chloride, is reported. The refraction index was represented by molar refraction. It was described as the sum of solutes’ partial molar refraction and solvent molar refraction. The solutes’ partial molar refraction was estimated from the molar refraction of the binary solutions. The excess molar refraction for these systems was described with the equation of Wang et al. The polarizability of the solutes present in the studied systems was estimated using the Lorenz–Lorenz relation. The results showed the model is appropriate for describing the systems studied; the interactions of boric acid, sodium, potassium, lithium, chloride, and sulfate ions with water molecules are relevant to explain the molar refraction and refractive index, and those for the binary systems of lithium chloride and sodium chloride are also relevant the ion–ion interactions. The model is robust and presents estimation capabilities within and beyond the concentrations and temperature range studied. Therefore, the outcomes represent valuable information to understand and follow the industrial processing of natural brines.

Prediction of organic compounds adsorbed by polyethylene and chlorinated polyethylene microplastics in freshwater using QSAR

Microplastics (MPs), a growing class of emerging pollutants in the environment, have attracted widespread attention due to their adsorption properties. Recent research on MPs has mainly concentrated on seawater, and little work has been conducted on freshwater. Investigating and predicting the adsorption behavior of organic pollutants by MPs are necessary in freshwater. In this study, the adsorption behavior of 13 organic chemicals by polyethylene (PE) and chlorinated polyethylene (CPE) MPs was determined under freshwater conditions. Results shows the majority of the organic chemicals exhibit no distinctive differences in their adsorption on two MPs. However, the adsorption of polycyclic aromatic hydrocarbons and chlorobenzene on CPE is obviously stronger than that on PE, and the result is a counter for two pesticides. Quantitative structure activity relationship (QSAR) analysis was performed for the prediction of adsorption capacity. A QSAR model with acceptable performance (R2 = 0.8586) was built to predict the adsorptive affinity (expressed as logKd) of organic compounds on the PE MPs via multivariable linear regression (MLR) on forty-nine determined and collected data. The octanol/water partition coefficient (logKow) and excess molar refractive index (E) play dominant roles in the model. A QSAR model with satisfactory performance (R2 = 0.9302) was also established for logKd values from CPE MPs in freshwater by using 13 adsorption data determined. The logKow and most negative charge on Cl atom (Q-max,cl) play decisive roles in the adsorption. The findings can provide a scientific basis for the risk assessment of waters contaminated by MPs and organic pollutants.

Study of the physical properties of 90 P2O5 + xV2O5 (10-x) BaO (0≤x≤3%) glasses

(90 P2O5 + x V2O5 + (10-x) BaO) (x = 0, 0.75, 1.50, 2.25 and 3.00 % in moles)) prepared by a melt quenching process. The physical properties, such as density (ρ) molar volume (VM), refractive index (n), metallicity (M), electron polarizability (α) and optical basicity (Λ), and were determined.XRD, DSC, Raman spectra, optical transmission, and photoluminescence spectroscopy were investigated at room temperature. The electrical properties were studied using an AC impedance spectroscopy. The observed increase in Tg with V2O5 reflects an increase in bond strength by the presence of the VOP bonds.At the 523−773 K temperature range following the Arrhenius law, the activation energy (≈0.276 eV) decreased with the Vanaduim rate. At the 423–523 K temperature range by Mott’s VRH model the highest density of Fermi states, N(Ef) values 3.45 1025 eV−1 cm-3 were obtained with PVB2.25 sample.Finally, the study exhibited a low relaxation time τrel≈1 μs and Vanadium substutition reduces the gap to 4.12 eV and the Urbach energy to 0.26 eV.

Study on the Optical Properties of High Refractive Index TeO2‐PbO‐ZnO‐BaF2 Glass System

The tellurite 60TeO2‐20PbO‐(20‐x)ZnO‐xBaF2 (x = 1, 3, 5, 6, 7, 9, and 11) series glass samples were prepared. The samples’ SEM, XRD, DSC, density, refractive index, and absorption spectra were tested. A self‐made optical platform was used to measure and calibrate the refractive index. The relationship between glass composition and crystallinity was discussed. The effects of density, molar refractive index, and metal standard value on the refractive index of glass samples were studied. The results showed that TPZBF glass has a high refractive index, and the refractive index increases with the increase in BaF2 content.

Dielectric properties, polarizability and molar refractive index of some VSrFeZnO glasses

Dielectric properties of a set of glasses having the composition (70-x)%V2O5 - x%ZnO − 10%SrO − 20%FeO is studied in terms of their permittivity and electric modulus. The dielectric data are collected at the frequencies 120, 103, 104 and 105 Hz and in the temperature range 300 − 523 K. The electric moduli are treated with different theoretical models. Good fitting to the experimental data are obtained with Cole–Cole and Davidson–Cole equations. The static relaxation time τ0 values are found to vary between 7.6x10−9 sec and 22.7x10−9 sec, and the parameters α and γ are found to be (α = 0.056 − 0.065) and (γ = 0.94 − 0.95). The calculated optical basicity values are found to decrease with increasing the %ZnO. The molar refractive index is found to be between 2.6 and 3.2. The calculated single bond strength values suggest the transfer of bond nature from the covalent to the ionic form. The obtained third-order nonlinear optical susceptibility χ(3) results and electronic polarizability calculations suggests these glasses to be good nominees for nonlinear optical applications.

Thermodynamic and transport properties of ternary mixture (ethyl oleate + n-hexadecane +1-butanol) and its binary constituents (ethyl oleate +1-butanol and ethyl oleate + n-hexadecane) at different temperatures and atmospheric pressure

Densities, viscosities, speeds of sound and refractive indices have been measured for the ternary system ethyl oleate + n-hexadecane +1-butanol, and for the corresponding binaries ethyl oleate +1-butanol and ethyl oleate + n-hexadecane, in the temperature range from T = (293.15 to 343.15) K and at atmospheric pressure. Experimental data were employed to calculate some derived thermodynamic parameters, i.e. excess molar volumes (VE), viscosity deviations (Δη) and deviations in refractive index (ΔnD). Additionally, molar excess Gibbs free energies of activation of viscous flow (ΔG⁎E) and deviations in isentropic compressibility (Δκs) were calculated. A graphical representation of excess molar volumes and refractive indices show positive deviation from ideal behavior for both binary systems whereas deviation in viscosity shows negative nature for the ethyl oleate + n-hexadecane system and an inversion sign for ethyl oleate +1-butanol binary system. A negative deviation in isentropic compressibility was confirmed for the systems ethyl oleate +1-butanol while positive deviation was observed in ethyl oleate + n-hexadecane system. It can be concluded that dispersive forces predominate between the components in binary systems and the observed behavior seems to suggest that the properties obtained for the ternary mixture are dominated by the binary effects. The viscosities of the binary systems were modeled by UNIFAC-VISCO, ASOG-VISCO, Teja-Rice and McAllister models. The results showed that McAllister's multibody model is suitable to describe viscosities for binary systems with maximum percentage deviations less than 0.5%.

Effect of Nd3+ ions on the structural, physical and emission properties of some As2O3.V2O5.CuO glasses

A set of Nd3+ doped vanadium arsenate glasses having formula 25%As2O3.70%V2O5. (5-x) %CuO.x%Nd2O3 (where x = 0, 0.5, 1, 1.5, 2 mol%) are manufactured by the ordinary melt quenching technique. These glasses are investigated by several tools. Complete amorphous phase is confirmed for all samples. The calculated optical basicity decreases with the increase of Nd2O3 mole% in the glasses, while the molar refractive index follows an opposite trend. The metallization criterion calculation confirms the insulating nature of the samples, and such nature increases with increasing the Nd2O3 content. Tg, Tc and thermal stability of the glasses are found to increase with increasing the Nd2O3 content in the glasses. Continuous addition of the Nd3+ ions increases the thermal conductivity of the glasses from 0.11 to 0.178 W/m.oC. Emission spectra due to 365 nm excitation light demonstrates emission peaks around 506, 542, 580 and 635 nm from the samples.

Assorted Interactions Prevalent in Uracil and Aqueous Gallic Acid Solution Explored by Physicochemical Contrivance

The solute-cosolute interaction of uracil by gallic acid has been studied through physicochemical investigation in aqueous environment. Here, we have carried out the density (ρ) and viscosity (η) measurements of uracil in w1= 0.001, 0.002 and 0.003 mass fraction of aqueous gallic acid binary mixtures at T= 298.15 K, 303.15 K and 308.15 K at pressure 1.013 bar. Some important parameters have been derived from the above physicochemical method, namely, limiting apparent molar volume (<i>φ_V</i>⁰) and viscosity <i>B</i>-coefficients using extended Masson equation and Jones-Dole equation respectively. The refractive index (<i>n_D</i>) has been done on the same system at T=298.15 K. Lorentz-Lorenz equation has used to evaluate molar refractive index (R_M) and limiting molar index (R_M⁰). The NMR study used to measure the plausible selective site of solute-cosolute interaction.<div><br></div>

Photoluminescence properties and energy transfer investigations of Gd3+ and Sm3+ co-doped ZnO–BaO–TeO2 glasses for solid state laser application

The physical, optical, photoluminescence properties of (54-x) TeO2 − 10ZnO − 35BaO − 1Sm2O3 − xGd2O3, where 0 ≤ x ≤ 3 (mol %) are investigated in this research. Five samples of glass were produced by the normal melt quenching process. The evidence indicates that the density of glass increased with increasing of Gd2O3. The molar volume and refractive index investigations have been used to consider the physical properties and optical properties of the produced glass system. Physical parameters such as polaron radius, inter-ionic radius and field strength for Sm3+/Gd3+ ions have been evaluated. The absorption spectra of glass contain peaks at 358, 404, 948, 1,085, 1,235, 1,385, 1490 and 1535 nm corresponding to the transitions from 6H5/2 to 4D3/2, 6P3/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, and 6H15/2, respectively. The emission spectra of glass show four bands at found and attributed to 563, 604, 646 and 709 nm by excitation at 275 nm. Judd-Ofelt parameters and radiative properties was investigated for 53.5TeO2 − 10ZnO − 35BaO − 1Sm2O3 − 0.5Gd2O3 glass. Energy transfer characteristics was observed in the present glasses. The emission intensity of Sm3+ increased with increasing of Gd2O3 concentration until 2 mol %, while the luminescence lifetime decreases with increasing of Gd2O3 content.

Thermodynamic study of ester diethyl tartrate and its binary systems with iso-alcohols

Densities of pure ester diethyl tartrate and alcohols isobutanol and isopentanol are measured on high pressures up to 60 MPa and temperatures from 293.15 K to 413.15 K, while thermophysical properties for two systems ester + alcohol are obtained on atmospheric pressure and temperatures 288.15–323.15 K. High pressure densities were correlated with Tammann-Tait equation. Experimental data on atmospheric pressure for mixtures were used to determine derived properties, excess molar volume, viscosity and refractive index deviations, which are then correlated with Redlich-Kister polynomial equation. To support the discussion regarding interactions, FT-IR analyses of pure components and mixtures with highest absolute values of excess molar volume were presented. Additionally, viscosity modelling was performed with predictive and correlative models and results were discussed from the point of potential usage of applied models to calculate viscosity of investigated systems.

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.

Characterization of 20Na2O·30((1−x)CaO·xSrO)·50P2O5 glasses for a resorbable optical fiber application

AbstractResorbable glasses with nominal molar compositions of 20Na2O·30[(1−x)CaO·xSrO]∙50P2O5, where x = 0, 0.25, 0.50, 0.75, and 1, were prepared and characterized. With the replacement of CaO by SrO, the molar volume, refractive index, and coefficient of thermal expansion increased, and the glass transition temperature, crystallization temperature, and viscosity decreased. The replacement of CaO by SrO decreased the dissolution rate in 37°C water by nearly an order of magnitude. Resorbable glass fibers drawn from melts of the 20Na2O·30CaO·50P2O5 glass exhibited decreasing transmission of laser light (632 nm) in a predictable way as the fiber dissolved in a phosphate buffer solution. This demonstrated that these glasses could be used to produce resorbable fibers for temporary biosensing or therapeutic applications.

Fabrication of Thin Films of Phosphonated Calix[4]Arene Bearing Crown Ether and Their Gas Sensing Properties

Calix[4]arenes bearing phosphate and crown ether groups are shown to hold considerable promise as the active layer in volatile organic compound (VOC) vapor sensor. Its chemical sensing selectivity and sensitivity can be altered by different alkyl side chains. These organic architectures were successfully deposited by the spin coating method on gold-coated glass surfaces. Surface plasmon resonance technique was used for VOCs detection to evaluate the chemical-sensing properties of these calix[4]arene derivatives. Spun thin films of calix[4]arene derivatives were exposed to a variety of VOC vapors, and the resonance angles changes of these films were recorded for the specific analyte vapors, such as chloroform, carbon tetrachloride, dichloromethane, ethanol, benzene, and toluene. Measurements were made at room temperature, and the responses were found to be fast and appeared to be completely reversible. The sensing results showed similar response patterns, and our data strongly indicate that response of used thin films of calix[4]arene derivatives to chloroform is much higher than those of any other VOCs used with the values of 0.47 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , 1.042 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , and 1.952 x 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> (% / ppm) for the compounds 1, 2, and 3, respectively. Furthermore, gas sensing interaction mechanisms of the thin films were evaluated in terms of the molar volumes, dipole moments, and refractive indexes of the analyzed gas molecules.