Spectroscopic Properties and Dispersion Parameters of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses

Glasses with the chemical formula 52B2O3 – 12SiO2- 26Bi2O3 – (10-x) TiO2 - Y2O3, :(0≤ x ≥ 10), the melt-quench method was used to prepare this glass system. The purpose of this article is to investigate the spectroscopic features of these glasses. The nature of the glass system has been investigated using X-ray diffraction analysis. In the current article, the molar volume acquired decreased while the density and refractive index increased. In the current article, Y2O3 plays an important role and impacts the spectroscopic characteristics of the samples accordingly. For all the present glasses, the optical bandgap is found to be in the semiconducting range. The optical bandgap enhances as Y2O3 rises, while Urbach energy reduces. Molar Refractivity, molar polarization, polarization, and optical basicity decrease with increasing Y2O3 content. Wemple and Didomenico principles were used for calculated the Eo and Ed dispersion. The significance of the Y2O3 modifier in the glass system signifies proved.

Ethylene Glycol as Entrainer in 1-Propanol Dehydration: Scrutiny of Physicochemical Properties of Ethylene Glycol+1-Propanol Binary Mixture at Different Temperatures

Density (ρ), and dielectric permittivity (ε) of the binary mixture of ethylene glycol + 1- propanol have been determined as a function of mole fraction of ethylene glycol at T = (298, 308 and 313)K. These measurements have been employed to compute thermodynamic properties like molar volume (V), and molar polarization (P) of the liquid mixtures. Excess properties such as VE, εE and PE for the binary mixture have also been calculated at different temperatures. In order to calculate the standard deviations of the excess properties, Redlich – Kister polynomial equation was used. The negative and positive values of the excess properties predicted the type and strength of molecular interactions between the components in the binary mixture.The excess molar volume for the mixture at all temperatures is found to be negative. The εE values for ethylene glycol + 1-propanol has been found to be negative at 298K and but positive values are obtained at 308 and 313K. The divergent magnitudes of εE values at different temperatures have been attributed to different strengths of hydrogen bond interactions as well as alignments of net dipoles.

Dielectric Study of Carboxyl (–COOH) Functionalized Multi-Walled Carbon Nano Tube-Silicone Oil Nanofluids at Different Temperatures

In this work, dielectric properties of carboxyl (–COOH) functionalized MWCNTs-Silicone oil (polydimethylsiloxanes) nanofluids have been studied at static frequency. Purchased carboxyl (–COOH)-f-multi-walled carbon nanotubes (MWCNTs) are purchased and characterized using transmission electron microscopy (TEM) technique. Carboxyl (–COOH)-f-MWCNT-Silicone oil nanofluids are prepared by dispersing COOH-MWCNT in Silicone oil (base fluid) with the help of probe sonicator. At various concentrations and at different temperatures dielectric parameters like static dielectric constant (ɛ0), excess dielectric constant (ɛE), dipole moment (μ), excess dipole moment (μE) and molar polarization (P) have been determined for COOH-f-MWCNT-Silicone oil nanofluids. The changes in the dielectric parameters with respect to five different concentrations and various temperatures (303 K to 323 K) are analyzed in the presence of intermolecular interactions happening in the COOH-f-MWCNT-Silicone oil nanofluid system. Excess dielectric constant and excess dipole moment values are found to be negative over entire concentration range of COOH-MWCNTs at every different temperature.

Study of dipolar association in polar–polar system of ethyl methyl ketone (EMK) and carboxylic acids vis-à-vis molecular interaction

Dielectric constant of binary mixtures of ethyl methyl ketone (EMK) with some carboxylic acid, namely, acetic acid, propionic acid, and butyric acid, is measured at 303.16 K and 455 kHz. The data are used to compute the mutual correlation factor, gab, excess molar polarization, ΔP, and excess Gibbs free energy, ΔG, of mixing to study the molecular interaction. The study reveals that interaction is maximum in EMK + butyric acid system and microheterogeneous β-clusters with antiparallel orientation of dissimilar molecules predominate in it.

DFT-based quantum theory QSPR studies of molar heat capacity and molar polarization of vinyl polymers

In this study, the DFT/B3LYP level of theory with the 6-31G (d) basis set was used to calculate a set of quantum chemical descriptors for structure units of vinyl polymers. These descriptors were used to predict the molar heat capacity of “liquid” at constant pressure (C P1(298 K)) and the molar Lorentz and Lorenz polarization (P LL). Two more physically meaningful quantitative structure-property relationship (QSPR) models obtained from the training sets applying multiple linear stepwise regression (MLR) analysis were evaluated externally using the test sets. Correlation coefficients between the predicted and the experimental values were: 0.998 for C P1(298 K) and 0.979 for P LL. The results indicate that the QSPR models constructed using quantum chemical descriptors can be applied to predict the properties of polymers confirming the role of quantum chemical descriptors in the QSPRs studies of polymers.