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A Novel molecular Schiff based organic crystal, (E)-4-Fluoro-2(Phenylimino)methyl)phenol), was synthesized and characterized by Thermogravimetric, Differential Scanning Calorimetry, UV Spectroscopy, Vicker’s Hardness, Microstructure and Powder X-Ray Diffraction. The 4F2PMP crystal involves the binding of molecules via an inherent O-H•••N hydrogen bond, S(6) forms the ring. The crystalline structure features C-H•••O hydrogen bonds. The phase transition-I, transition-II, and phase transition-III were confirmed by variable-temperature powder XRD and DSC analysis and showed endothermic reaction. The thermodynamic and kinetics parameters values, including such enthalpy, entropy of fusion, melting point, and activation energy, have been determined by exploring DSC and TGA data respectively. The superior performance and highest hardness of this 4F2PMP crystal indicate that it’s a super hard material. The vicker’s elastic properties, such as young’s modulus, bulk modulus, shear modulus, and poisson’s ratio, have been determined by Vicker’s hardness (Hv). The morphology of the 4F2PMP crystal is tightly packed grain without any cracks, EDAX confirms the composition analysis.

This contribution presents an extensive literature survey of the calorimetric properties, namely enthalpy and entropy of fusion, of alkyl‐based molecules. Building on the well‐known linear correlation of the named properties to the carbon number in n‐alkanes, saturated fatty acids (FA), and saturated monoacid triglycerides (TAGs), the calorimetric properties of TAGs are reviewed. No straightforward correlation using a single ordering parameter, i.e., carbon number, can be derived for TAGs. This is not surprising due to the complexity of this particular class of molecules differing in alkyl‐chain distribution over the glycerol backbone and chain saturation. A linear correlation of enthalpy and entropy of fusion is evident for molecule classes for which both properties correlate linearly with the carbon number, e.g., n‐alkanes. Despite the complexity of TAGs, it is possible to establish a linear correlation between enthalpy and entropy of fusion even though no underlying single ordering parameter can be identified. A linear fit reveals discrepancies between saturated and unsaturated molecules but independence of polymorphic forms and chain length differences in mixed‐acid TAGs. Moreover, the slopes of the linear fits for data on n‐alkanes, saturated FA, and saturated mono‐acid TAGs are found to be in the vicinity of the melting temperature of polyethylene.

The Ni3Sn2 phase plays an important role in numerous fields including solder alloys and lithium storage. However, the precise measurements of many parameters which are essential in describing the physical properties of this phase, such the Gibbs-Thomson coefficient, solid–liquid interfacial energy, grain boundary energy and entropy of fusion per unit volume have not been carried out yet. In this work, the equilibrated grain boundary groove (GBG) shapes for a solid Ni3Sn2 phase in equilibrium with the liquid were observed from Sn-36 at.%Ni peritectic alloy in a linear temperature gradient by using a Bridgman type directional solidification apparatus after experiencing a thermal stabilization time of 8 h. The time required to obtain the GBG shapes in this alloy with a large freezing range was analyzed through the temperature gradient zone melting (TGZM) theory. The Gibbs-Thomson coefficient, solid-liquid interfacial energy and grain boundary energy for the solid Ni3Sn2 phase in equilibrium with liquid were determined in this work, which will help the growth and property control of the fields mentioned above.

Extended Hildebrand solubility approach (EHSA) was applied to estimate and correlate the solubilities of itraconazole in 1,4-butanediol + water mixtures at 298.15 K. Experimental solubilities and properties like entropy of fusion and ideal mole fraction solubilities were determined. EHSA was applied to estimate interaction parameter ′W′ to understand the solute solvent interaction. Theoretical solubilities were calculated by using ′W′ as a function of solubility parameter of solvent blend (δ1) and by direct method using logarithmic experimental solubilities (logX2) against solubility parameter of solvent mixture (δ1). Prediction capacities of EHSA and direct method were compared using mean percent deviations obtained while comparing theoretical solubilities with experimental ones. Itraconazole solubility was increased in all the proportions of solvent mixtures and was found to be highest at 0.9 mass fraction of 1,4-butanediol where solubility parameter of drug matched with solvent mixture. Prediction capacity of EHSA was found to be better with regular polynomial equation of order 5 with mean deviation of − 1.69%. Using EHSA, the solubility of any solute can be adequately predicted with the knowledge of few physicochemical properties.

Molten phases of metal-organic networks offer exciting opportunities for using coordination chemistry principles to access liquids and glasses with unique and tunable structures and properties. Here, we discuss general thermodynamic strategies to provide an increased enthalpic and entropic driving force for reversible, low-temperature melting transitions in extended coordination solids and illustrate this approach through a systematic study of a series of bis(acetamide)-based networks with record-low melting temperatures. The low melting temperatures of these compounds are the result of weak coordination bonds, conformationally flexible bridging ligands, and weak electrostatic interactions between spatially separated cations and anions, which collectively reduce the enthalpy and increase the entropy of fusion. Through a combination of crystallography, spectroscopy, and calorimetry, enthalpic trends are found to be dictated by the strength of coordination bonds and hydrogen bonds within each compound, while entropic trends are strongly influenced by the degree to which residual motion and positional disorder are restricted in the crystalline state. Extended X-ray absorption fine structure (EXAFS) and pair distribution function (PDF) analysis of Co(bba)3[CoCl4] [bba = N,N'-1,4-butylenebis(acetamide)], which features a record-low melting temperature for a three-dimensional metal-organic network of 124 °C, provide direct evidence of metal-ligand coordination in the liquid phase, as well as intermediate- and extended-range order that support its network-forming nature. In addition, rheological measurements are used to rationalize differences in glass-forming ability and relaxation dynamics. These results provide new insights into the structural and chemical factors that influence the thermodynamics of melting transitions of extended coordination solids, as well as the structure and properties of coordination network-forming liquids.

The rheological properties of tamarind seed polymer are characterized for its possible commercialization in the food and pharmaceutical industry. Seed polymer was extracted using water as a solvent and ethyl alcohol as a precipitating agent. The temperature’s effect on the rheological behavior of the polymeric solution was studied. In addition to this, the temperature coefficient, viscosity, surface tension, activation energy, Gibbs free energy, Reynolds number, and entropy of fusion were calculated by using the Arrhenius, Gibbs–Helmholtz, Frenkel–Eyring, and Eotvos equations, respectively. The activation energy of the gum was found to be 20.46 ± 1.06 kJ/mol. Changes in entropy and enthalpy were found to be 23.66 ± 0.97 and −0.10 ± 0.01 kJ/mol, respectively. The calculated amount of entropy of fusion was found to be 0.88 kJ/mol. A considerable decrease in apparent viscosity and surface tension was produced when the temperature was raised. The present study concludes that the tamarind seed polymer solution is less sensitive to temperature change in comparison to Albzia lebbac gum, Ficus glumosa gum and A. marcocarpa gum. This study also concludes that the attainment of the transition state of viscous flow for tamarind seed gum is accompanied by bond breaking. The excellent physicochemical properties of tamarind seed polymers make them promising excipients for future drug formulation and make their application in the food and cosmetics industry possible.

We apply the efficient two-optimized references thermodynamic integration using Langevin dynamics method [Phys. Rev. B 96, 224202 (2017)2469-995010.1103/PhysRevB.96.224202] to calculate highly accurate melting properties of Al and magnetic Ni from first principles. For Ni we carefully investigate the impact of magnetism on the liquid and solid free energies including longitudinal spin fluctuations and the reverse influence of atomic vibrations on magnetic properties. We show that magnetic fluctuations are effectively canceling out for both phases and are thus not altering the predicted melting temperature. For both elements, the generalized gradient approximation (GGA) and the local-density approximation (LDA) are used for the exchange-correlation functional revealing a reliable ab initio confidence interval capturing the respective experimental melting point, enthalpy of fusion, and entropy of fusion.

Measurements were made of the heat capacity of crystalline and liquid bromobenzene from 11 to 300 K, of the triple point and heat of fusion at the triple point and of the heat of vaporization at one temperature. The adiabatic calorimeter used was precise over most of its range to ±0.l percent; the purity of the sample was 99.998 mol percent. The triple point of pure bromobenzene is 242.401 K (—30.749 °C) ±0.0l0°; the enthalpy and entropy of fusion are, respectively, 10702 ± 5 J mol(−1) and 44.150 ± 0.022 J K(−1) mol(−1). The heat and entropy of vaporization at 293.00 K are, respectively, 43 963 ±60 J mol(−1) and 150.0 ± 0.2 J K(−1) mol(−1). Tables are given for the thermodynamic functions of the condensed phases from 0 to 300 K; the functions for the ideal gas from 100 to 1500 K, calculated from spectroscopic and molecular data using statistical mechanical methods, are also tabulated. The entropy of the ideal gas at 293.00 K and one atmosphere, from statistical mechanics, is 323.63 J K(−1) mol(−1); the same quantity from the experimental measurements (third law) is 323.73 J K(−1) mol(−1). No anomalies or additional transitions were observed.

With a view to synthesize and characterize the enhanced pharmaceutical properties of the solid-liquid dispersions of binary drug system through a green chemical technique, the present communication have been undertaken for detailed investigation of thermodynamic and interfacial properties of benzimidazole (BI) and β. naphthol (βN) binary eutectic and non-eutectic drug dispersions. Eutectic solid dispersion was observed at 0.657-mole fraction of β. naphthol (βN) and at melting temperature 90°C. Thermodynamic quantities; Partial and Integral excess Gibbs energy (gE), excess enthalpy (hE), excess entropy (sE) of eutectic and non-eutectic dispersions were determined with the help of activity coefficient data. The negative deviation from ideal behaviour has been seen in the system which refers to a stronger association between unlike molecules during the formation of the binary mix. The negative value of Gibbs free energy of mixing (DGM) refers to the mixing for all eutectic and non-eutectic dispersions are spontaneous. The solid-liquid interfacial characteristics i.e., the entropy of fusion per unit volume (DSV), solid-liquid interfacial energy (s), roughness parameter (α), grain boundary energy and roughness parameter (α) of eutectic and non-eutectic solid dispersions have been reported. The size of the critical nucleus at different undercooling has been found in nanoscale, which may be a big significance in the pharmaceutical world. The value of roughness parameter, α > 2 was observed which manifests the faceted and irregular growth leads in the system.

The functions of formation at T = 298.15 K of calcium-ammonium nitrate decahydrate, 5Ca(NO3)2·NH4NO3·10H2O, have been computed on the basis of experimental results obtained in this work. Single-phase crystalline calcium-ammonium nitrate decahydrate has been synthesized and checked by chemical analysis, thermogravimetry, differential scanning calorimetry, powder X-ray diffraction, and infrared spectroscopy. The enthalpy of dissolution of the decahydrate in water at T = 298.15 K was measured in a sealed swinging calorimeter with an isothermal jacked. The low-temperature heat capacity of the solid has been measured by vacuum adiabatic calorimetry in the temperature range (7 to 338) K. The temperature, enthalpy, and entropy of fusion of the crystalline hydrate have been determined via differential scanning calorimetry at high pressure. A second-order solid-solid transition for the substance in the temperature range (300 to 330) K has been detected by methods of adiabatic calorimetry and differential scanning calorimetry.

The phase diagram of anthranilic acid (AA)–m-nitro benzoic acid (NBA) system, determined by the thaw–melt method, shows the formation of a 2:1 (AA:NBA) inter-molecular compound (IMC) and two eutectics E1 and E2 containing 0.084 and 0.917 mol fractions of AA, respectively, with one eutectic on either side of the IMC. The heat of mixing, entropy of fusion, roughness parameter, interfacial energy, and the excess thermodynamic functions were calculated from the enthalpy of fusion data, obtained by the DSC method. While the spectroscopic investigations (IR and NMR) and optical studies suggest the presence of hydrogen bonding between the components, the powder X-ray diffraction spectra of eutectics and the IMC suggest that the eutectic E1 is a mechanical mixture of the IMC and NBA and the eutectic E2 is a mechanical mixture of the IMC and AA. A single crystal of cocrystal of AA and NBA was grown using slow evaporation technique at room temperature from its saturated solution in methanol solvent. Single-crystal analysis of the grown cocrystal shows the mode of the intermolecular hydrogen bonding in the molecule and the triclinic crystal structure with P − 1 space group.

The present study deals with the synthesis of two new compounds namely, benzamide – 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid–2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV–Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10−3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

The paper presents a thermodynamic study of the melting transition in Au nano-clusters with a number of atoms (N) in the range 103 < N

In this work, the glass-forming ability (GFA) of sodium metaphosphate (NaPO3) is focused, and the cooperative nature of its thermodynamics and kinetics is explored. The critical cooling rate (Rc) of this substance is determined, giving a value as low as ~ 0.5 K/s, and the fragility m-index of 83±3 is calculated based on the calorimetric measurements. Among oxide systems with a mixture of covalent-ionic bonds, the compatibility of relatively high fragility of NaPO3 and its good GFA seems an exception. The good GFA is ascribed to its impressive liquidus viscosity (ηL) and the low entropy of fusion normalized by the structural parameter 'beads' (ΔSm/beads). Strikingly, an extended survey of various glass formers delivers a correlation between ηL and ΔSm/beads, verifying the significance of low entropies of fusion for the glass formation. A critical liquidus viscosity (ηL ~ 0.01 Pa-s) is featured, below which this thermo-kinetic correlation cannot be detected.

In recent years, high-entropy materials have become increasingly complex, outgrowing simple solid-solution based calculations of configurational entropy, and with that, the previously established metrics for high-, medium-, and low-entropy. Those previous metrics are derived from metals-specific approximations of the entropy of fusion and the internal energy of a monatomic gas, and thus, do not apply to other materials. A new entropy metric is proposed that is universally applicable for crystalline materials, from simple solid-solution high-entropy alloys to high-entropy materials with complex crystal structures and multiple sublattices. Additionally, the methods for calculating configurational entropy in complex crystal structures are discussed.

The heat capacity of 2-methylfuran in the temperature range of 8–350 K was determined by vacuum adiabatic calorimetry. The temperature, the enthalpy and the entropy of fusion and purity of investigated sample were determined by fractional melting. The smoothed thermodynamic functions (changes in enthalpy, entropy and Gibbs energy) in the region of 8–350 K were calculated. The entropies of formation and Gibbs energies of formation of 2-methylfuran at 298.15 K in the liquid and ideal gas states were found, using the literature data.

An effort has been made to reassess the phase predicting capability of various thermodynamic and topological parameters across a wide range of HEA systems. These parameters are valence electron concentration, atomic mismatch (δ), electronegativity difference (Δχ), mixing entropy (ΔS mix), entropy of fusion (ΔS f), and mismatch entropy (S σ ). In continuation of that, two new parameters (a) Modified Darken–Gurry parameter (A = Sσ * χ) and (b) Modified Mismatch Entropy parameter (B = δ* Sσ) have been designed to predict the stable crystal structure that would form in the HEA systems considered for assessment.

Morphology, orientation relationships, and formation mechanism of TiN in Fe-17Cr ferritic stainless steel were investigated theoretically and experimentally by scanning electron microscopy, X-ray diffractometer, and electron backscatter diffraction. Two types of structures of TiN, without cores and with cores, were observed in the solidified microstructure. The dimensionless entropy of fusion (Δ S m / R ) of TiN is calculated as 2.5, which suggests that TiN will exhibit regular faceted morphology. The planar disregistry between (111) plane of TiN and (110) plane of ferrite is calculated as 17.1%, which indicates that it is not sure if TiN can act as the heterogeneous site for ferrite nucleation during solidification. Pole figures of TiN and ferrite by EBSD show that Kurdjumov-Sachs orientation relationship between TiN and ferrite exists, which confirms that TiN can act as the heterogeneous site for ferrite. In addition, based the EDS mapping, TiN in the microstructure should form during solidification rather than solid-state transformation.

In this study, density functional theory (DFT) calculations and the best available reliable predictive methods are used to assess performance, thermodynamics, physical and sensitivity of several high nitrogen content energetic tetrazole derivatives. Detonation pressure and velocity of these compounds are greater than 470 GPa and 10.2 km/s, respectively. Furthermore, suitable methods are used to study the condensed phase heat of formation, Gibbs free energy of formation, heat of sublimation, heat of combustion, melting point, enthalpy of fusion, entropy of fusion, specific impulse, Gurney velocity, strength, deflagration temperature, impact sensitivity and shock sensitivity of the novel compounds. The predicted results of the new compounds are compared with the calculated and experimental values of N,N-bis(1H-tetrazol-5-yl)amine (HTBA), dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) as high performance energetic compounds.

4D printing is a new process that involves the use of 3D-printed objects and materials able to change shape over time. Therefore, a comprehensive understanding of 3D-printed objects is needed prior to developing 4D-printed ones. Selective laser melting (SLM) is a very promising 3D printing technique; however, because of the intense heat input, problems such as balling phenomena, deteriorated surface finish, tensile residual stress, and part distortion are still frequently observed in the SLM process. For such cases, micro-/nano-scale heat management becomes a key problem. Indeed, heat conduction during the SLM process is significantly affected by powder diameter and compactness. The thermodynamic behaviors of powder due to laser heating are considerably different from that of a solid bulk body. In this paper, molecular dynamics (MD) and empirical embedded atom computational methods are applied to study the thermodynamic properties of Ag nanoclusters, which are 2.1-6.9 nm in diameter during the heating and cooling process. We find that the melting point, heat of fusion, entropy of fusion, and surface energy are highly dependent on nanocluster size. Remarkably, we define the mesoscale regime where the properties of nanoclusters can be described in terms of macroscopic concepts with well-defined bulk and surface thermodynamic properties.

The behavior of the equilibrium melting temperature ( T m o ) of poly( l -lactic acid) with pressure estimated using the Gibbs-Thomson method is presented. Differential scanning calorimetry and a High pressure differential thermal analyzer have been used to determine the melting temperatures of samples isothermally crystallized at atmospheric pressure and at pressures ranging from atmospheric to 300 MPa respectively. Lamellar thickness of the crystals was determined from small angle X-ray scattering. The ( d T m o d P ) o was found to follow the second order polynomial T m o = 206 + 0.309 P – 3.86 × 10 −4 P 2 . The enthalpy and entropy of fusion of the perfect crystal up to 300 MPa determined through the Clapeyron equation remained more or less similar up to 200 MPa but increased significantly at 300 MPa. The Δ H f 0 and Δ S 0 at atmospheric pressure were calculated to be 94.5 Jg -1 and 0.197 JK −1 g −1 , respectively while the fold surface energy was calculated to be 64 × 10 −3 Jm −2 .

Phase diagrams of o-phenylenediamine (OPDA)–N,N-dimethylaminobenzaldehyde (DMAB) and salicylamide (SAM)–m-nitro benzoic acid (NBA) systems, determined by the thaw-melt method, show the formation of two eutectics and one inter-molecular compound (IMC) in each case. These inter-molecular compounds were synthesized by the solvent-free method involving thermally initiated molten state reactions. Their characterization by the IR and the 1H NMR techniques suggest the formation of a new compound. Absorption spectrum of IMC of OPDA–DMAB system shows band at 245 nm due to the π → π* transition and another broad band observed from 280 to 440 nm is attributed to the n → π* transition. Their IMC shows fluorescence at 388 nm with a Stokes shift (93 nm) and quantum efficiency (0.0032) upon excitation at 350 nm in ethyl alcohol. Emission and absorption were observed in case of SAM–NBA system too. While the values of enthalpy and entropy of fusion of inter-molecular compound in case of OPDA–DMAB are 23.58 kJ mol−1 and 57.20 J mol−1, respectively, in the case of SAM–NBA system the corresponding values are 69.50 kJ mol−1 and 170.00 J mol−1. The values of interfacial energy in case of OPDA–DMAB and SAM–NBA inter-molecular compounds are 37.84 × 10−3 and 40.39 × 10−3 J m−2, respectively.

A homologously isomorphous series of compounds can allow determination of local contributions to crystal properties. Historically, melting points have contributed little to structural theory, but those of a series of long-chain diacyl peroxides allow the measurement of localized structural contributions to solid-state thermodynamics, and demonstrate that a bromine substituent at a lamellar interface can make negative contributions to both the enthalpy and entropy of fusion, thus acting more “liquid-like” when in the crystal than when in the melt. We discuss how Istanbul, and opposition to Hitler, led Friedrich Breusch and his students to measure at least 1242 accurate melting points, and how this legacy may prove valuable in understanding crystalline solids, especially those that show odd-even melting-point alternation.

A simplified procedure with minimum input information is presented to predict an analytical equation of state for crystallizable polymer melts from enthalpy of fusion and crystalline density as scaling constants. The second virial coefficients are calculated from a two-parameter corresponding states correlation obtained from two constants which are heat of fusion, ΔHfus, and the molar density at the crystalline point, ρcrys. This new correlation has been applied to the Ihm-Song-Mason equation of state to predict the volumetric behavior of some polymer melts at compressed state with temperature range from 311.5 K to 557.25 K and pressures up to 200 MPa. For 924 data points, the overall average absolute relative deviation (AARD) of pVT properties was found to be 0.46%. The isothermal compressibility coefficients and liquid bulk modulus have also been predicted using mTM EOS. From 840 data points examined, the AARD of both isothermal thermodynamic properties was equal to 9.71 × 10− 2%. Also the enthalpy of fusion (ΔHfus) and entropy of fusion (ΔSfus) of three polymer melts are predicted using the mTM EOS. Our calculations on the volumetric and thermodynamic properties of studied polymers reproduce the literature data with reasonably good accuracy.

In this article, density functional theory (DFT) and electrostatic potential (ESP) analysis are used to predict enthalpy of sublimation, crystal density and enthalpy of formation for some isomers of 20 new derivatives of nitroazacubane as new high performance energetic compounds. These data are used to predict detonation and physicothermal properties of the mentioned compounds, including heat, pressure, velocity and temperature of detonation as well as deflagration temperature, melting point and entropy of fusion through appropriate theoretical methods. The predicted properties are compared with octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) as one of well-known high performance energetic compounds. Detonation performance of nitroazacubane compounds are surprisingly much higher than HMX, which confirm that they can be introduced as novel high performance energetic compounds.

Cefoxitin acid is one kind of important pharmaceutical intermediate. Its solubility is crucial for designing and optimizing the crystallization processes. In this work, the solubility of cefoxitin acid in organic solvents (methanol, acetonitrile, ethanol, isopropanol, n-propanol and ethyl acetate), water and water-methanol mixtures was measured spectrophotometrically using a shake-flask method within the temperature range 278.15–303.15 K. PXRD data and the Karl Fischer method were used to verify the crystal form stability of cefoxitin acid in the solubility measuring process. The melting points, the enthalpy and entropy of fusion were estimated. Results showed that the solubility of cefoxitin acid increases with the increasing temperature in all tested solvents in this work, and the solubility of cefoxitin acid increases with the increasing methanol concentration in water-methanol mixtures. The experimental solubility values were well correlated using the modified Apelblat equation, NRTL model and CNIBS/R-K model. An equation proposed by Williamson was adopted to calculate the molar enthalpy during the dissolution process.