scholarly journals Thermodynamic Characteristics of Phenacetin in Solid State and Saturated Solutions in Several Neat and Binary Solvents

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4078
Author(s):  
Maciej Przybyłek ◽  
Anna Kowalska ◽  
Natalia Tymorek ◽  
Tomasz Dziaman ◽  
Piotr Cysewski
Keyword(s):  
Heat Capacity ◽  
Solid State ◽  
Binary Mixtures ◽  
Thermodynamic Characteristics ◽  
Precise Determination ◽  
Binary Solvents ◽  
Binary Solvent ◽  
Aqueous Mixtures ◽  
Scanning Calorimetry ◽  
Aqueous Binary Mixtures

The thermodynamic properties of phenacetin in solid state and in saturated conditions in neat and binary solvents were characterized based on differential scanning calorimetry and spectroscopic solubility measurements. The temperature-related heat capacity values measured for both the solid and melt states were provided and used for precise determination of the values for ideal solubility, fusion thermodynamic functions, and activity coefficients in the studied solutions. Factors affecting the accuracy of these values were discussed in terms of various models of specific heat capacity difference for phenacetin in crystal and super-cooled liquid states. It was concluded that different properties have varying sensitivity in relation to the accuracy of heat capacity values. The values of temperature-related excess solubility in aqueous binary mixtures were interpreted using the Jouyban–Acree solubility equation for aqueous binary mixtures of methanol, DMSO, DMF, 1,4-dioxane, and acetonitrile. All binary solvent systems studied exhibited strong positive non-ideal deviations from an algebraic rule of mixing. Additionally, an interesting co-solvency phenomenon was observed with phenacetin solubility in aqueous mixtures with acetonitrile or 1,4-dioxane. The remaining three solvents acted as strong co-solvents.

scholarly journals High-temperature heat capacity ErInGe2O7 and TbInGe2O7 in the range 350-1000 K

2019 ◽  
Vol 486 (2) ◽  
pp. 193-196
Author(s):  
L. T. Denisova ◽  
A. D. Izotov ◽  
Yu. F. Kargin ◽  
L. A. Irtugo ◽  
V. V. Beletskiy ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
High Temperature ◽  
Solid State ◽  
Thermodynamic Properties ◽  
Solid State Reactions ◽  
Effect Of Temperature ◽  
Scanning Calorimetry ◽  
High Temperature Heat Capacity ◽  
Temperature Heat

SmFeGe2O7 germanate was obtained by solid-state reactions from stoichiometric mixtures of starting oxides with multistage firing within 1273-1473 K. The effect of temperature on the heat capacity of the compound was studied using differential scanning calorimetry. Based on the dependence Cp = f(T), its thermodynamic properties are calculated.

scholarly journals Heat capacity and thermodynamic properties of SmFeGe2O7 in the range 350-1000 K

2019 ◽  
Vol 487 (6) ◽  
pp. 640-643
Author(s):  
L. T. Denisova ◽  
A. D. Izotov ◽  
Y. F. Kargin ◽  
L. A. Irtugo ◽  
V. V. Beletskiy ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Solid State ◽  
Thermodynamic Properties ◽  
Solid State Reactions ◽  
Effect Of Temperature ◽  
Scanning Calorimetry

SmFeGe2O7 germanate was obtained by solid-state reactions from stoichiometric mixtures of starting oxides with multistage firing within 1273-1473 K. The effect of temperature on the heat capacity of the compound was studied using differential scanning calorimetry. Based on the dependence Cp = f(T), its thermodynamic properties are calculated.

Phase Transitions in the Alkali C1 —n. C4 Alkanoates

1975 ◽  
Vol 30 (11) ◽  
pp. 1447-1457 ◽  
Author(s):  
P. Ferloni ◽  
M. Sanesi ◽  
P. Franzosini
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Phase Transitions ◽  
Solid State ◽  
Thermal Behaviour ◽  
Heat Capacity Data ◽  
Supplementary Information ◽  
State Transitions ◽  
Scanning Calorimetry ◽  
Capacity Data

The enthalpies and entropies of fusion and of solid state transitions in Li formate and acetate; Li, Na, K, Rb, Cs propionates; Li, Rb, Cs n.butyrates were determined by differential scanning calorimetry. Supplementary information was provided through conductance measurements on solids. The collected data, together with those from previous papers, allowed to give a picture of the thermal behaviour of the alkali C1-n. C4 alkanoates.Heat capacity data on solid and molten Na formate, acetate and propionate were also determined

Solubility and Preferential Solvation of Piroxicam in Neat Solvents and Binary Systems

2018 ◽  
Vol 232 (2) ◽  
pp. 257-280 ◽  
Author(s):  
Gabriela Tatiana Castro ◽  
Mauricio Andrés Filippa ◽  
Cecilia Mariana Peralta ◽  
María Virginia Davin ◽  
María Cristina Almandoz ◽  
...  
Keyword(s):  
Binary Mixtures ◽  
Binary Systems ◽  
Preferential Solvation ◽  
Water Concentration ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Ideal Behavior ◽  
Vis Spectroscopy ◽  
Linear Solvation Energy ◽  
Aqueous Binary Mixtures

AbstractThe solubilization and solvatochromic behavior of piroxicam (PRX) were analyzed using UV-vis spectroscopy in neat (protic and aprotic) and binary solvent mixtures. The effects of solvent dipolarity/polarizability and solvent–solute hydrogen bonding interactions on the absorption maxima were evaluated by means of the linear solvation energy relationship concept of Kamlet and Taft. This analysis indicated that both interactions play an important role in the position of the absorption maxima in neat solvents. While, the PRX solubility depends on the solute–solvent specific interactions, polarizability and the cohesive forces of the solvent, manifested mainly by means of the Hildebrand’s solubility parameter. Preferential solvation (PS) was studied in 10 binary mixtures. A non-ideal behavior of the wavenumber curve as the function of analytical mole fraction of co-solvent was detected. Index of preferential solvation, as well as the influence of solvent parameters were calculated. The process of dissolution was analyzed in aqueous binary mixtures of ethanol, ethylene glycol and propylene glycol. They were not spontaneous in all proportions, but when water concentration decreases in the mixtures, the process becomes more spontaneous.

scholarly journals Высокотемпературная теплоемкость апатитов Pb-=SUB=-10-x-=/SUB=-Nd-=SUB=-x-=/SUB=-(GeO-=SUB=-4-=/SUB=-)-=SUB=-2+x-=/SUB=-(VO)-=SUB=-4-x-=/SUB=- (x=0-3)

2019 ◽  
Vol 61 (7) ◽  
pp. 1397
Author(s):  
Л.Т. Денисова ◽  
Е.О. Голубева ◽  
H.В. Белоусова ◽  
В.М. Денисов ◽  
Н.А. Галиахметова
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
High Temperature ◽  
Solid State ◽  
Gibbs Energy ◽  
Entropy Change ◽  
Apatite Structure ◽  
Scanning Calorimetry ◽  
High Temperature Heat Capacity ◽  
Temperature Heat

The Pb10-xNdx(GeO4)2+x(VO4)4-x (x = 0 ‒ 3) compounds with the apatite structure have been synthesized from PbO, Nd2O3, GeO2 and V2O5 oxides by the solid-state synthesis with successive burning in air within 773-1073 K. The high-temperature heat capacity of the compounds obtained was determined by differential scanning calorimetry. The CP = f(T) data have been used to evaluate their thermodynamic properties (enthalpy increment, entropy change, and reduced Gibbs energy).

scholarly journals Quantifying Solid-State Mixtures of Crystalline Indomethacin by Raman Spectroscopy Comparison with Thermal Analysis

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Eman Atef ◽  
Harsh Chauhan ◽  
Dev Prasad ◽  
Dunesh Kumari ◽  
Charles Pidgeon
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Solid State ◽  
Binary Mixtures ◽  
Quantitative Method ◽  
Reliable Method ◽  
Polymorphic Form ◽  
Scanning Calorimetry ◽  
Polymorphic Forms

This paper investigates Raman spectroscopy as a quick and reliable method to quantify the alpha (α) and gamma (γ) polymorphic forms of indomethacin compared to differential scanning calorimetry (DSC). Binary mixtures with different ratios of α and γ indomethacin were prepared and analyzed by Raman and DSC. The Raman method was found to be more reliable and superior compared to DSC. The partial conversion of the alpha to gamma polymorphic form during the DSC measurement was the major limitation for the use of full DSC as a quantitative method and resulted in difference between the calculated and measured enthalpy of both polymorphic forms.

scholarly journals Thermal Analysis of Binary Mixtures of Imidazolium, Pyridinium, Pyrrolidinium, and Piperidinium Ionic Liquids

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6383
Author(s):  
Elena Gómez ◽  
Pedro Velho ◽  
Ángeles Domínguez ◽  
Eugénia A. Macedo
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Thermal Behavior ◽  
Binary Mixtures ◽  
Heat Capacities ◽  
Viable Alternative ◽  
Transition Temperatures ◽  
Scanning Calorimetry

Ionic liquids (ILs) are being widely studied due to their unique properties, which make them potential candidates for conventional solvents. To study whether binary mixtures of pure ionic liquids provide a viable alternative to pure ionic liquids for different applications, in this work, the thermal analysis and molar heat capacities of five equimolar binary mixtures of ionic liquids based on imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with dicyanamide, trifluoromethanesulfonate, and bis(trifluoromethylsulfonyl)imide anions have been performed. Furthermore, two pure ionic liquids based on piperidinium cation have been thermally characterized and the heat capacity of one of them has been measured. The determination and evaluation of both the transition temperatures and the molar heat capacities was carried out using differential scanning calorimetry (DSC). It was observed that the thermal behavior of the mixtures was completely different than the thermal behavior of the pure ionic liquids present, while the molar heat capacities of the binary mixtures were very similar to the value of the average of molar heat capacities of the two pure ionic liquids.

scholarly journals Heat capacity of Inconel 617 alloy

2021 ◽  
Vol 2119 (1) ◽  
pp. 012138
Author(s):  
D A Samoshkin ◽  
A Sh Agazhanov ◽  
S V Stankus
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Solid State ◽  
Present Article ◽  
Scanning Calorimetry ◽  
Reference Table ◽  
Temperature Range ◽  
Temperature Dependences ◽  
Inconel 617 ◽  
Estimated Error

Abstract In the present article, the heat capacity of Inconel 617, one of the most promising superalloys, was investigated. The measurements were carried out in the temperature range from 300 to 1270 K of the solid state. The method of differential scanning calorimetry was applied using DSC 404 F1 Pegasus calorimeter. The estimated error of the received data was 2-4% depending on the temperature. The fitting equations for the temperature dependences of the heat capacity and the reference table of recommended values have been received for use in various engineering and scientific tasks.

scholarly journals Experimental and Theoretical Screening for Green Solvents Improving Sulfamethizole Solubility

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5915
Author(s):  
Piotr Cysewski ◽  
Maciej Przybyłek ◽  
Rafal Rozalski
Keyword(s):  
Dimethyl Sulfoxide ◽  
Binary Mixtures ◽  
Theoretical Models ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Green Solvents ◽  
Environmental Friendliness ◽  
Vast Number ◽  
Pharmaceutical Ingredients ◽  
Aqueous Binary Mixtures

Solubility enhancement of poorly soluble active pharmaceutical ingredients is of crucial importance for drug development and processing. Extensive experimental screening is limited due to the vast number of potential solvent combinations. Hence, theoretical models can offer valuable hints for guiding experiments aimed at providing solubility data. In this paper, we explore the possibility of applying quantum-chemistry-derived molecular descriptors, adequate for development of an ensemble of neural networks model (ENNM), for solubility computations of sulfamethizole (SMT) in neat and aqueous binary solvent mixtures. The machine learning procedure utilized information encoded in σ-potential profiles computed using the COSMO-RS approach. The resulting nonlinear model is accurate in backcomputing SMT solubility and allowed for extensive screening of green solvents. Since the experimental characteristics of SMT solubility are limited, the data pool was extended by new solubility measurements in water, five neat organic solvents (acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, and methanol), and their aqueous binary mixtures at 298.15, 303.15, 308.15, and 313.15 K. Experimentally determined order of decreasing SMT solubility in neat solvents is the following: N,N-dimethylformamide > dimethyl sulfoxide > methanol > acetonitrile > 1,4dioxane >> water, in all studied temperatures. Similar trends are observed for aqueous binary mixtures. Since N,N-dimethylformamide is not considered as a green solvent, the more acceptable replacers were searched for using the developed model. This step led to the conclusion that 4-formylmorpholine is a real alternative to N,N-dimethylformamide, fulfilling all requirements of both high dissolution potential and environmental friendliness.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

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