Values Of Molar Volume Research Articles

Excess Thermodynamic Properties and FTIR Studies of Binary Mixtures of Toluene with 2-Propanol or 2-Methyl-1-Propanol

Physical properties of the binary solutions, toluene with 2-propanol and 2-methyl-1-propanol, were measured at T = 293.15, 298.15, 303.15, 308.15, and 313.15 K and P = 100 kPa. The experimental density values were tested with the Emmerling et al. and Gonzalez-Olmos–Iglesias equations. The results indicate that the equation by Emmerling et al. is the best to correlate the density for toluene + 2-methyl-1-propanol system, while for toluene + 2-propanol, both proposed equations are proper to correlate the density with composition and temperature. The viscosity results were verified with different models containing two adjustable parameters. The values of viscosity deviation (∆η), excess molar volume (VE), excess Gibbs energy (ΔG*E), partial molar volumes (V1¯ and V2¯), and apparent molar volume (Vφ,1 and Vφ,2) were calculated. The values of the excess molar volume were positive for both systems, while negative values were obtained for the viscosity deviation and the excess Gibbs energy. The excess properties of the mixtures were adjusted to the Redlich–Kister equation. The values of thermodynamic functions of activation of viscous flow were computed and analyzed. Additionally, the Prigogine–Flory–Patterson (PFP) theory was applied to calculate VE and then compared with experimental values. The values of the percentage absolute average deviation obtained suggest the validity of this theory. The Fourier transform infrared spectroscopy (FTIR) spectra of the binary solutions studied in this work allowed for the understanding of the interactions between the molecules of these systems.

Structural investigation and dc conductivity of Bi2O3–B2O3 glasses

The structure of xBi2O3∙(100–x)B2O3 with (30 ≤ x ≤ 65 mol%) glasses was investigated by FTIR, XRD, TEM, SEM and dc conductivity. The factor of four coordinated boron atoms N4 increases up to 50 mol% Bi2O3 then decreases for further increase in Bi2O3 content. FTIR analyses indicate that Bi2O3 heads for creating a matrix of its own rather than modifying the borate matrix and this behavior gradually increases with increasing its concentration in the matrix. There is a linear increase in both experimental density and molar volume values with replacing B2O3 by Bi2O3, moreover a strong correlation between the computed and experimental density and molar volume values could be noticed. XRD patterns confirm that no sharp peaks for untreated samples whereas Bi2O3 crystalline phase appears for heat treated samples. TEM and SEM show the presence of some small phases with different sizes formed of clusters, these phases increase in size and became predominant with heat treatment. The conductivity increases while the activation energy seems to be constant. This rare behavior is interpreted in the light of forming Bi2O3 former matrix.

Partial molar volumes of 1–1 electrolytes at high T and P: correlations and predictions

Knowledge of the partial molar volumes of aqueous ions allows accurate calculation of the pressure dependence of equilibrium constants, solubility of minerals, etc., thus being useful for thermodynamic modeling of hydrothermal processes. This study analyzed methods to correlate and predict the values of the partial molar volumes at infinite dilution, V2o, for 1–1 electrolytes and singly charged ions at elevated T and P. Since the precise experimental values of the dielectric constant of water are measured only up to 873 K, we were interested only in non-electrostatic ways to correlate V2o data. First of all, we compiled the V2o values at T > 373 K for the following 1–1 electrolytes: HCl, LiCl, LiI, LiNO3, LiOH, NaF, NaCl, NaBr, NaI, NaNO3, NaOH, NaHCO3, NaClO4, NaH2PO4, NaTr (Tr stands for triflate), KF, KCl, KBr, KI, KNO3, KOH, CsBr, and NH4Cl. Relations, following from the “density” model and from the Fluctuation Solution Theory (FST) were employed to analyze data. It was concluded that at the current state of knowledge of V2o the FST-relations for electrolytes are recommended mainly to reject strongly deviating experimental outliers. However, the “density” model provides a simple and fairly accurate way to describe the compiled set of data with only two parameters for each ion, n and Vhc, values of which were evaluated for the following singly-charged ions: H+, Li+, Na+, K+, Cs+, NH4+, F-, Cl-, Br-, I-, OH–, NO3–, H2PO4-, HCO3–, ClO4-, Tr- (Tr = triflate). Following Mesmer et al. (1988), we consider the fitting parameters Vhc and n to be related to the intrinsic volume of the ion and to the number of water molecules transferred from the bulk water to a hydration shell around the ion, respectively.Although the values of n and Vhc were fitted from data at temperatures from 373 to 673 K and water densities, do, from 0.5 to 1.1 g cm−3, apparently, they predict realistic V2o values at temperatures up to 1600 K and do ranges from 0.2 to 1.6 g cm−3.

Existence of nano-sized aggregates in aniline and chloroform binary system

The liquid binary system of aniline (ANL) and chloroform (CHL) was discovered to form aggregates at a nano-size level responsible for the peculiar trends of some physico-chemical properties, reflected in morphology. The density and viscosity were recorded in the temperature range from 273.15 K to 313.15 K at ten different molar fractions. While the correlation of viscosity and density with molar fraction indicated a modest deviation from ideality, the excess molar volume values derived from density values exhibited a large discrepancy from the directly measured results, suggesting the potential aggregation leading to local inhomogeneity of mixtures’ concentration. On the other hand, FT-IR and Raman spectra showed no significant frequency shift both for N-H stretching on ANL and C-H stretching vibration on CHL upon mixing, in agreement with quantum mechanical calculations, which revealed the presence of a few complexes with stoichiometry ANL:CHL = 1:2 and 2:2, formed through CH···π interactions. The nano-scale morphology was characterised using the dynamic light scattering (DLS) method and SEM imaging. The calculated molecular electrostatic potential (MEP) of complexes indicated the capability for further association among complexes or between complexes and ANL or CHL molecules to form larger aggregates. For the first time, nano-sized aggregates were spotted for a liquid binary system made of small-sized organic molecules (solvents) using the combination of thermodynamic measurement, vibrational spectroscopy, quantum mechanical calculations and SEM imaging.

Incorporation of neodymium, holmium, erbium, and samarium (oxides) in zinc-borotellurite glass: Physical and optical comparative analysis

Investigating the effect of different types of rare-earth oxides on zinc borotellurite glass is important to determine the potential application in optical devices. The addition of rare-earth oxides in zinc borotellurite glass is well-known to enhance the optical properties due to the effects of 4f-4f transitions. In this work, we aim to compare the effect of different rare-earth oxides on zinc borotellurite glass denoted as ZBTNd, ZBTHo, ZBTEr and ZBTSm. The glass samples were successfully fabricated via the melt-quenched technique. The physical investigation of the glasses has been done by measuring the density and molar volume. It was found that ZBTNd glass has the lowest density than the other glasses due to the small atomic radius in neodymium oxide. High-density value for ZBTHo glass shows potential to be used as radiation shielding properties. The high value of molar volume for ZBTNd glass is advantageous for fiber optics as ZBTNd glass has good performance in elasticity. It was found that ZBTEr has a lower refractive index than the other glasses due to low dispersion characteristics. However, ZBTEr glass has good performance to be used in optical communication applications. It was found that the optical absorption shifts to a longer wavelength beginning from ZBTEr > ZBTHo > ZBTNd > ZBTSm. The optical band gap energy for ZBTEr glass is higher than the other glasses due to the Coulomb repulsion energy for erbium which is greater than neodymium and samarium and slightly higher than holmium. The pattern of electronic polarizability for all glasses was found as follows ZBTSm>ZBTNd>ZBTEr>ZBTHo. The optical basicity for ZBTEr was found highest which indicates a higher acidity, meanwhile, the ZBTNd glass has the lowest value which corresponds to a higher basicity.

Thermo-acoustic properties of monosaccharides D(−)-ribose and D(+)-xylose in aqueous diammonium hydrogen phosphate solutions at different temperatures

The volumetric and acoustic properties are used for investigating the interactions of polyhydroxy solutes D(−)-ribose and D(+)-xylose in different concentrations of diammonium hydrogen phosphate (DAP) solutions. Densities and speeds of sound of D(−)-ribose and D(+)-xylose in aqueous diammonium hydrogen phosphate (DAP) solutions have been measured over a temperature range of (298.15–318.15) K and at experimental pressure p = 0.1 MPa. Different parameters viz apparent molar volumes, Vϕ, partial molar volumes, apparent molar isentropic compression, partial molar isentropic compression, partial molar volume of transfer and molar isentropic compression of transfer are obtained using experimental density and ultrasonic speed data. The calculated parameters are discussed in rapports of solute–solvent interactions in solutions indicated the presence of ion-ion, ion-polar, hydrophilic-hydrophilic and hydrophobic–hydrophobic interactions in these ternary solutions, which was also confirmed from obtained positive values of apparent molar volume and negative values of apparent molar isentropic compressibility. Pair (VAB, KAB) and triplet (VABB, KABB) interaction coefficients determined by means of McMillan-Mayer theory are used to acquire valuable information about the dominance of pairwise interactions in the studied mixtures.

Densities and volumetric properties of pyridine with 2-dimethylaminoethanol and 2-diethylaminoethanol at temperatures from 293.15 to 313.15 K

ABSTRACT The densities ρ of binary mixtures of 2-(dimethylamino)ethanol and 2-diethylaminoethanol with pyridine were measured over the entire concentration range at 293.15, 303.15 and 313.15 K. The values of excess molar volume, V m E , apparent molar volume, V φ , DMAE and V φ , DEAE ; partial molar volumes, V ˉ m , 1 and V ˉ m , 2 , excess partial molar volumes, V ˉ m , 1 E and V ˉ m , 2 E have been computed using the experimental observations. The partial molar volumes, V ˉ m , 1 o and V ˉ m , 2 o ; excess partial molar volumes, V ˉ m , 1 oE and V ˉ m , 2 oE at infinite dilution were also calculated. The variations of these parameters as a function of composition and temperature are discussed in terms of the intermolecular interactions in the studied binary mixtures.

Volumetric-acoustic investigations of antihypertensive drug in aqueous acetaminophen system

Captopril is an antihypertensive drug used to lower the blood pressure in living organisms. In order to arbitrate and understand the synergy between antihypertensive drug viz., captopril and antipyretic drug acetaminophen in aqueous system, the density and sound velocity at different temperatures (293.15 to 318.15) K with temperature interval of 5 K were measured using Anton Paar density sound velocity meter (DSA5000M). The experimental measured data were further used to calculate volumetric and acoustic parameters such as apparent and partial molar volume, apparent and partial molar isentropic compressibility, partial molar expansibility, Hepler’s constant, compressibility hydration number, and intermolecular free length. Positive values of apparent molar volume (ϕv) and negative values of apparent and partial molar compressibility (ϕk and ϕko) of captopril in water and aqueous acetaminophen solution has been shown strong intermolecular interactions in solutions. Negative values of Hepler's constant indicate the structure breaking behavior of drug in water.

Green development of samarium borosilicate glasses doped silica gel waste for stable orange colored visible host material

This study presents a new way to make luminescent glass doped with SiO2 components using recycled silica gel waste from laboratories and ball milling and melt-quenching methods. A study is conducted on the optical, photoluminescence, and X-ray luminescence characteristics of glasses doped with recycled silica gel waste (RSGW); (69-Y)B2O3–18Li2O–12BaO–YRSGW-1.0Sm2O3 (Y= 0–60 mol%) and Sm2O3-doped; (40-Y)B2O3–18Li2O–12BaO–30RSGW-YSm2O3 (Y= 0–2 mol%). The glass samples undergo characterization using several spectroscopic techniques under standard ambient conditions. The density and refractive index of the YSilicagelSm glasses increase, while their molar volume value decreases with the increase in RSGW content in the glass system. Furthermore, the absorption spectra display the hypersensitive transitions 6H5/2→6P3/2 and 6H5/2→6F7/2 in the visible and near-infrared ranges, respectively. The glasses exhibit four prominent transitions that are indicative of the Sm3+ ion as a result of photoluminescence and X-ray luminescence. Among these, the 4G5/2→6H7/2 (at 600 nm) transition is the most intense. Photoluminescence and X-ray luminescence suggest the highest emission intensity occurs in the host composition containing 30 mol% RSGW. According to the CIE 1931 chromaticity diagram, this glass produces a reddish-orange illumination. A further experiment was prepared with a host glass (40-Y)B2O3–18Li2O–12BaO–30RSGW-YSm2O3 with varying Sm2O3 concentrations. The results from both luminescence experiments support that the concentration of Sm2O3 increases up to 1.0 mol% and then decreases, which is the appropriate quenching concentration of Sm3+. This not only offers another way to repurpose waste but also presents interesting novel possibilities for materials science and photonics research.

Investigation of intermolecular interactions of l-Valine and l-Phenylalanine with muscle relaxant drug mephenesin molecule prevalent in aqueous solution by various physico-chemical methods at T=298.15K–313.15K

A complete chemical analysis of significant intermolecular interactions of l-Valine (L-Val) and l-Phenylalanine (L-Phe) with Mephenesin (MEPN) molecules in aqueous solution has been studied by different physicochemical methodologies at various temperatures (T = 298.15 K–313.15 K at an interval of 5 K) and concentrations (0.001 mol kg−1, 0.003 mol kg−1, 0.005 mol kg−1) of aqueous MEPN solution. The limiting apparent molar volume (φV0) and experimental slope (SV*) values are found from the equation of Masson, viscosity A and B-coefficient determined using the equation of Jones-Doles, molar refraction (RM) and limiting molar refraction (RM0) derived by the Lorentz-Lorenz equation, express that in our experimental solution of amino acids (AAs) in aqueous MEPN, the solute-solvent interaction predominates over the solute-solute and solvent-solvent interactions for these ternary solutions. These are also justified by the measurement of various thermodynamic parameters, free energy of activation of viscous flow per mole of solvent(Δμ1°#) and solute (Δμ2°#), activation of viscous flow of enthalpies (ΔH°#) and entropies (ΔS°#). The characteristics of structure-breaking of solutes in the aqueous drug solution have been identified by Hepler's method and dB/dT value. The spectroscopic methods like UV–visible and proton-NMR studies help to explicate the strong AA-MEPN interactions in the solution phase and obtain a good correlation with theoretical studies. Theoretical investigations are checked to authenticate the experimental observations and according to both studies, L-Phe-MEPN interaction is greater than L-Val-MEPN interaction. The experimental and correlated research data are useful for the development of model combinations of AAs with drug molecules in pharmaceutical and medicinal chemistry.

Effect of the inclusion of Fe2O3 on the optical and electrical transport properties into sodium-zinc-phosphate quaternary glassy systems

Glass systems, xFe2O3–(35-x)Na2O–25ZnO–40P2O5) (x = 10, 15, 20, and 25 mol%), were prepared using the melt-quenching technique. FTIR analysis revealed stretching vibrations of the P–O–P and P–O bonds and XRD investigation revealed a pure amorphous structure. It was discovered that with rising Fe2O3 content (x), the values of density increased, but the values of molar volume decreased. The Fe2O3 incorporation into the glass matrix resulted in decrement in the optical band gap energy (Eopt) value from 2.99 to 2.16 eV. The addition of Fe2O3 to the glass network reduced the quantity of non-bridging oxygen ions, improving the observed refractive index value. According to the Mott and Greaves model, the small polaron hopping model was responsible for the DC conductivity mechanism, and the density of states at the Fermi level increased as DC conductivity increased with increasing Fe2O3 content, but hopping distance (Rhop) and hopping energy (Whop) sharply decreased. It was concluded that the AC conductivity mechanism followed the correlated barrier hopping model as the power-law exponent (s) of Jonscher's universal power law decreased with temperature. AC conductivity increased with rising Fe2O3 concentration due to a decrement in the polaron hopping distance value and an increment in the concentration of defect pair states.

A Study on the Physical, Optical and Radiation Shielding Capabilities of Phosphate Zinc Telluride Glasses as a Result of ZnO/In2O3 Translocation

New In2O3-doped phosphate zinc tellurite glasses synthesized using melt-quenching method were investigated. It was observed that the synthesized glasses exhibit transparent properties. Densities of synthesized glasses changed significantly related to the doping ratio of In2O3. This implies that radiation shielding abilities can be enhanced. In other respects, the almost linear elevation in molar volume values indicated that the glass network expanded as a result of the ZnO/In2O3 translocation. As the additive ratio increases, the optical band gap value increases from 2.96 eV to 3.47 eV, while the Urbach energies decrease from 0.350 eV to 0.180 eV. In2O3 contribution has a regulatory effect on the structure of phosphate zinc tellurite glasses. In phosphate zinc tellurite glasses evaluated in terms of radiation shielding properties, it was observed that the In2O3 additive contributed significantly to the shielding properties and the glass with the best radiation shielding was 6 mol% In2O3 doped glass. It is obvious that by raising the density values of the produced glasses, the ZnO/In2O3 translocation in phosphate zinc tellurite glasses enhanced their radiation shielding properties.

Influence of anion structure on volumetric properties of dilute binary systems containing carboxylate functioned trihexylammonium ionic liquids in toluene / dodecane

We are actively involved in synthesis of hydrophobic ionic liquids, their volumetric behaviour in various solvents of different polarity and their application in metal ions extraction from water. In continuation of previous work, we are presenting new protic ionic liquids (PILs) containing Trihexylammonium cation and carboxylate anions namely Trihexylammonium propionate [THA][Pro] and Trihexylammonium pentanoate [THA] [Pent]. The simultaneous measurements of densities, ρ along with speeds of sound, u for binary systems of [THA][Pro] and [THA][Pent] in toluene and in dodecane were collected. The measurements were carried out in dilute concentrations range of PILs, at 0.1 MPa and different temperatures from 293.15 K to 328.15 K. The experimental values of densities, ρ and speeds of sound, u, were utilized to obtain calculated values of apparent molar properties: Vϕ (apparent molar volume) and Ks,ϕ (apparent molar isentropic compressibility). It is observed that the apparent molar properties of investigated systems are quite sensitive to variation in temperature, solvent and anion’s structure of PILs. The values of Vϕ and Ks,ϕ increases with each increment in studied temperature and when toluene was replaced by dodecane as a solvent in the system. The each addition of –CH2 group in anion chain of PILs leading to increase Vϕ whereas decrease with concentration of PILs in the binary system. The limiting values of apparent molar volume, Vϕ∞ and apparent molar isentropic compressibility, Kϕ∞ were also reported. The strength of interactions between PIL-PIL and PIL-solvent in studied binary systems was explained by Sk and Sv parameters. The PILs + dodecane systems exhibit greater interaction between PILs and solvent than binary systems of PIL + toluene.

Effect of samarium oxide on the structural and ligand field parameters of iron cations inside sodium borate glass

In this work, we prepared sodium borate glass doped with different amounts of iron (Fe2O3) and samarium oxides (Sm2O3). The effects of replacing Fe2O3 with Sm2O3 on the transparency, ligand field parameters, and structural properties were studied using different techniques such as FTIR, density, optical absorbance and optical transmittance. Further, we explored the effect of sunlight on the optical transmittance at 90 min of irradiation time. Our results showed that, with further additions of Sm2O3, the BO4 units, density values increased, and ligand field splitting increased. In contrast, molar volume values decreased. The transparency of the glass specimens showed increased behavior with further Sm2O3 additives. Moreover, the transmittance of the glass samples showed decreasing values with exposure to sunlight. This behavior was attributed to the creation of structural defects inside the glasses with further sunlight irradiation. Moreover, the percent of change in optical transmittance for all glass samples is insignificant (<10%). This small percentage of change in optical transmittance shows that the glasses are stable when exposed to sunlight. Further, these results make them potential candidates to be used in photovoltaic modules.

The influence of Dy3+ ions on physical, structural, optical, and thermoluminescence characteristics of Li2O – BaO – B2O3 – P2O5 glass system

Dy3+-activated glasses with composition 15Li2O - 25BaO - (40-x)B2O3 – 20P2O5 – xDy2O3, where x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%, were synthesised using melt quenching technique for studying their physical, structural, optical, and thermoluminescence properties. The physical attributes were assessed using density and molar volume values. X-ray diffraction proved amorphous nature of glasses while Fourier transform infrared spectroscopy revealed the presence of structural groups. Optical absorption spectra with wavelengths spanning from 300 to 1200 nm were used to examine different optical properties. With an aim to study dosimetric properties, the glasses were irradiated with various gamma doses (50 Gy to 10 kGy). Chen's peak shape approach was used to establish kinetic parameters of glow curves in 325–500 K temperature range. The results suggest that due to high thermoluminescence efficiency, the glass sample with 0.8 mol% of Dy3+ concentration is best suitable for the dosimetric applications.

Hazardous radiation protective glasses for medical and research laboratories

In the current study, the bismuth oxide (Bi2O3) content was inter-substituted with gadolinium oxide (Gd2O3) in sodium borate glass. Glass sample density and molar volume values show a reverse trend. The optical transparent radiation shielding glasses are more commonly used materials in hospitals or any hazardous radiation working environments, the glasses used in this work are more emphasized on their superior transmittance and acceptable for shielding materials for commercial purposes. The optical band gap value was calculated using the Tauc plot and absorption fitting method. Radiation shielding parameters like mass attenuation co-efficient, effective atomic number, effective electron density, equivalent atomic number, lead equivalent thickness, half value layer, tenth value layer, Geometric-Progression fitting parameters like (b, c, a, XK, and d), γ-ray build-up factor, and exposure build-up factor have all been evaluated. In the current work, photoluminescence studies for Gd3+ ions were investigated and discussed.

Thermodynamic properties of {glycerol (1) + tert-butanol (2)} mixtures at temperatures from 278 K to 323 K and pressures up to 100 MPa

In the present study the densities at atmospheric pressure and the compression coefficients of a binary liquid mixture {glycerol (1) + tert-butanol (2)} were measured within the temperature range from 278.15 K to 323.15 K (278.15, 288.15, 288.15, 308.15 and 323.15) and pressures up to 100 MPa (10, 25, 50, 75 and 100). Due to the limited solubility of tert-butanol in glycerol and the transition of the mixture to the solid phase the measurements at 278.15 K and 100 MPa were carried out up tox2 = 0.45 (x2 is the mole fraction of tert–butanol). The excess molar volumes, molar isothermal compression, molar isobaric thermal expansion, isochoric coefficient of thermal pressure mixtures, as well as the partial molar volumes of the mixture components, including their limit values, were calculated. The excess molar volume values at 323.15 K (the only temperature at which the compression was measured over the entire composition range) were found to be negative. The partial molar volume of glycerol (GL) at 323.15 K was characterized by the presence of a baric inversion region. The limiting partial molar volume of GL was shown to decrease in its own environment as the pressure rose and to increase in the TBA environment. The molar isothermal compression of the mixture varied depending on the composition without extremes, and the partial molar isothermal compression of GL had negative values. The molar isobaric thermal expansion of the mixture in the area of small tert-butanol (TBA) additives changed slightly at low temperatures and pressures and the increase in both the pressure and the temperature led to dispersion of their concentration dependences. The isochoric coefficient of thermal pressure decreased with an increase in x2, forming a small plateau at small TBA additions. The results obtained were discussed from the perspective of solute–solvent and solute–solute interactions.

The structure, optical basicity, ligand field strength and shielding parameters of alkali/alkaline borate glasses doped with V2O5

In this work, we study the structural, optical and radiation shielding properties of Na2O–CaO-borate glass doped with different amounts of V2O5. A glass system with the composition (10.5CaO+ 16.5Na2O+ (73-x)B2O3+ xV2O5; where x = 0, 2.5, 5 and 10.5 mol%) was produced following the melt quenching technique. The molar volume and density of glasses both increase with the increase in V2O5:B2O3 ratios. Moreover, the average ligand field strength reduced from 2.32 to 2.15 × 1016 cm2 with the increase in V2O5:B2O3 ratios, which correlates with the increased values of molar volume and interatomic separations. Furthermore, the optical basicity of the glass samples increased from 0.601 to 0.666 with increasing V2O5:B2O3 ratios. The optical absorption spectra are studied for further investigation of the optical features. To extract the absorption edge and the absorption bands, a deconvolution process was applied to the absorption spectra. The obtained bands from this deconvolution process confirmed the presence of vanadium in its oxidation states V3+, V4+ and V5+. Furthermore, more additions of V2O5 produced an obvious reduction in Eg values from 3.69 to 3.08 eV along with a redshift in the fundamental absorption edges. These results were attributed to the further creation of nonbridging oxygens within the glass matrix. Furthermore, the addition of V2O5 rather than B2O3 enhances the radiation shielding parameters. Accordingly, the CaNaBV10.5 glass sample is the best attenuator among the fabricated CaO–Na2O–B2O3–V2O5 glasses due to the highest mass attenuation coefficient and lowest half-value layer. Moreover, the half-value layer values of the present glasses were compared to some common materials in the radiation shielding field. From this comparison, we concluded that all glass samples are better than commercial glass windows and ordinary concrete.

Excess Volume for Acetylene Tetrachloride with Pyridine, Methoxybenzene, 2-Butanone and 1,4-Dioxane at 298.15K

A dilatometric measurement have been carried out for getting excess volumes, VE, in the liquid state for mixtures of acetylene tetrachloride (CHCl2CHCl2), with pyridine (C5H5N), methoxybenzene (C6H5O CH3), 2-butanone (CH3COC2H5) and 1,4-dioxane (1,4-C4H8O2) at 298.15K and under atmospheric pressure. The values of excess molar volume, VE, are negative in sign for all the mixtures over whole composition range. Obtained data have been fitted by Redlich-Kister type polynomial smoothing equation. The results are discussed in the light of molecular interactions occurred between components in the liquid state.

Effect of ZnCl2 on structural and optical features of TeO2–B2O3–Bi2O3–ZnCl2 glasses

Tellurium dioxide-based quaternary glass system 60TeO2–15B2O3-(25-x) Bi2O3-xZnCl2 (0 ≤ x ≤ 20, in the step of 5 mol%) was synthesized by melt quenching technique. The XRD analysis was utilized to confirm that the glass samples were amorphous. The resultant values of molar volume, density, oxygen packing density, and glass transition temperature were shown to decrease with rise in ZnCl2 content. By employing vibrational spectroscopy, TeO2 endures as structural units trigonal pyramidal TeO3, TeO3+1, trigonal bipyramidal TeO4, together with TeO6 polyhedral. The optical characterization of the current glass system shows the presence of indirect transitions with optical band gap range from 2.16 eV to 3.02 eV. Along with the rise in ZnCl2 content, the Urbach energy value shows a tendency towards lowering values (0.436 eV–0.203 eV), which denotes a reduction in defect concentration. Metallization criterion values fall between 0.329 and 0.389 indicates that the current glass system can be utilizes for non-linear applications.