Thermochemical Calculations Research Articles

Preparation and characterization of multifunctional piezoenergetic polyvinylidene fluoride/aluminum nanocomposite films

We prepared poly(vinylidene fluoride) (PVDF) and aluminum composite dense films using a tape caster and investigated the microstructural, thermal, and electrical properties and the combustion behavior of the films as a function of nano-aluminum (nAl) solids loading (5–30 wt. %). We found that the addition of nAl facilitates the formation of piezoelectric β and γ phases of PVDF as determined by x-ray diffraction and Fourier transform infrared spectroscopy. At higher nAl solid loadings, the lower onset temperature of the pre-ignition and decomposition reactions have been observed. Moreover, the intentionally incorporated porosity into the films slightly affected the thermal decomposition behavior. While the dielectric constant of the films increases with higher nAl content, the dielectric breakdown strength of the films decreases significantly. The critical active nAl content for the films to exhibit self-propagated reaction was determined to be between 10 and 15 wt. %. Thermochemical calculations using the NASA CEA code showed the maximum flame temperature of 1750 °C near the stoichiometric ratio (∼20 wt. %). The burning rate of the films is enhanced drastically at ambient conditions with further addition of nAl. However, the films with active nAl content over 20 wt. % showed lower flame temperatures, which is due to the reduction of hydrofluoric acid gas generation and the incomplete combustion of Al to form aluminum monofluoride (AlF), instead of aluminum fluoride (AlF3) gas. The fabrication of energetic thin films with tunable properties could enable their use in multifunctional energetic material systems.

Modeling high burnup fuel thermochemistry, fission product release and fuel melting during the VERDON 1 and RT6 tests

This paper presents simulations of the VERDON 1 and RT6 tests (temperature increase up to fuel-clad melting, oxidizing and/or reducing conditions within the furnace) performed with high burnup UO2 fuel (i.e., up to 72 GWd/tU) and considering a coupling between irradiated fuel thermochemistry and a fission gas release model. The thermochemical calculations rely on the Thermodynamics of Advanced Fuels - International Database (TAF-ID) for the description of the phases likely to form from the 15 fission product considered in the fuel (Ba, Ce, Cs, I, La, Mo, Nd, Np, Pd, Rh, Ru, Sr, Tc, Te, Zr) and on the OpenCalphad solver for the minimization of the Gibbs energy of the system. The gas release model describes a diffusion process for the gases within equivalent spherical grains. It accounts for the gases formed by reaction between the fission products as well as the chemically inert noble gases. The progressive fission product depletion of the fuel due to their release in gas form closes the coupling. The impact of the fission product release kinetics on the thermochemical equilibria within the fuel is then studied by coupling the thermochemical calculations with a gas diffusion model. The coupled simulations led to a very good agreement with the release kinetics of various fission products (I, Te, Cs, Mo, Ba). The released fractions of the low-/non-volatile fission products and of uranium, plutonium are also well reproduced. The observed differences in the fuel-clad melting temperatures in the two tests (2200 °C during RT6 and 2600 °C during VERDON 1) are however not reproduced by the simulations.

Modulation of the Directionality of Hole Transfer between the Base and the Sugar-Phosphate Backbone in DNA with the Number of Sulfur Atoms in the Phosphate Group.

This work shows that S atom substitution in phosphate controls the directionality of hole transfer processes between the base and sugar-phosphate backbone in DNA systems. The investigation combines synthesis, electron spin resonance (ESR) studies in supercooled homogeneous solution, pulse radiolysis in aqueous solution at ambient temperature, and density functional theory (DFT) calculations of in-house synthesized model compound dimethylphosphorothioate (DMTP(O-)═S) and nucleotide (5'-O-methoxyphosphorothioyl-2'-deoxyguanosine (G-P(O-)═S)). ESR investigations show that DMTP(O-)═S reacts with Cl2•- to form the σ2σ*1 adduct radical -P-S[Formula: see text]Cl, which subsequently reacts with DMTP(O-)═S to produce [-P-S[Formula: see text]S-P-]-. -P-S[Formula: see text]Cl in G-P(O-)═S undergoes hole transfer to Gua, forming the cation radical (G•+) via thermally activated hopping. However, pulse radiolysis measurements show that DMTP(O-)═S forms the thiyl radical (-P-S•) by one-electron oxidation, which did not produce [-P-S[Formula: see text]S-P-]-. Gua in G-P(O-)═S is oxidized unimolecularly by the -P-S• intermediate in the sub-picosecond range. DFT thermochemical calculations explain the differences in ESR and pulse radiolysis results obtained at different temperatures.

Calculated estimations of the performance for TKX-50 based formulations

A computational study of the detonation characteristics of several explosive formulationsbased on the energetic material TKX-50 has been carried out. Materials such as paraffin, HTPB, GAP, AMMO and BAMO were considered as fillers or binders. The influence of such fillers (with a volumetric content of up to 50 %) on the detonation characteristics of the composite energetic materials was investigated. The influence of porosity on the detonation characteristics of composite explosive formulations with a binder mass content of 5 and 10% was determined. An analysis of the (limited) experimental data for the detonation velocity of explosive formulations based on TKX-50 was undertaken. The experimentally determined detonation velocities of three explosive formulations with inert and energetic binders which have been previously published in the literature were considered and analysed. Good agreement was found between the calculated and experimental results for the detonation velocity. A computational study of the explosion impact of charges of TKX-50, as well as of explosive formulations based on it containing the above-mentioned binders, on copper plates with a thickness of 1 mm and on layers with a thickness of 50 mm was carried out. The mass content of binders in the explosive formulations was 5 %. The charges were 50 mm thick and consisted of compact or porous materials with a porosity of 2 %. The Explo5 and Ansys Autodyn programs were used to perform thermochemical, thermodynamic and gas-dynamic calculations.

Physico-Chemical Properties and DFT Calculations of 2-Methoxy – 4 - (Prop-1-En-1-Yl) Phenol (ISOEUGENOL) Using Gausssian Basis Set

<p>Physico-chemical properties plays an important role in determining toxicity of a material hence were calculated using acdlab/chemsketch and the data predicted is generated using ACD/Labs Percepta Platform - PhysChem Module. Gaussian 09, RevisionA.01, software package was used for the theoretical quantum chemical calculations of 2-methoxy -4-(prop-1-en-1-yl) phenol commonly called Isoeugenol. DFT/B3LYP/6-311G (d, p) basis was used to perform geometric optimization and vibrational frequency determination of the molecule. The statistical thermochemical calculations of the molecule were done at DFT/B3LYP/6-311G (d, p) basis set to calculate the standard thermodynamic functions: heat capacity (CV), entropy (S) and Enthalpy (E). DFT/B3LYP/6-311G (d, p) basis set was used to calculate the various NLO properties like dipole moment (µ), mean linear polarizability (α), anisotropic polarizability (Δα), first order hyperpolarizability (β), second order hyperpolarizability (γ) in terms of x, y, z components for Isoeugenol (2-methoxy -4-(prop-1-en-1-yl) phenol. Same basis set was used to carry out Mulliken population analysis. UV-Visible absorption spectra, ECD spectra, electronic transitions, vertical excitation energies and oscillator strengths of Isoeugenol (2-methoxy -4-(prop-1-en-1-yl) phenol) were computed by Time Dependent DFT (TD-DFT) method using the same basis set. FMO analysis, Molecular electrostatic potential study was also done using the same basis set.</p>

Laser-based detection of methane and soot during entrained-flow biomass gasification

Methane is one of the main gas species produced during biomass gasification and may be a desired or undesired product. Syngas CH4 concentrations are typically >5 vol-% (when desired) and 1–3 vol-% even when efforts are made to minimize it, while thermochemical equilibrium calculations (TEC) predict complete CH4 decomposition. How CH4 is generated and sustained in the reactor core is not well understood. To investigate this, accurate quantification of the CH4 concentration during the process is a necessary first step. We present results from rapid in situ measurements of CH4, soot volume fraction, H2O and gas temperature in the reactor core of an atmospheric entrained-flow biomass gasifier, obtained using tunable diode laser absorption spectroscopy (TDLAS) in the near-infrared (1.4 µm) and mid-infrared (3.1 µm) region. An 80/20 wt% mixture of forest residues and wheat straw was converted using oxygen-enriched air (O2>21 vol%) as oxidizer, while the global air-fuel equivalence ratio (AFR) was set to values between 0.3 and 0.7. Combustion at AFR 1.3 was performed as a reference. The results show that the CH4 concentration increased from 1 to 3 vol-% with decreasing AFR, and strongly correlated with soot production. In general, the TDLAS measurements are in good agreement with extractive diagnostics at the reactor outlet and TEC under fuel-lean conditions, but deviate significantly for lower AFR. Detailed 0D chemical reaction kinetics simulations suggest that the CH4 produced in the upper part of the reactor at temperatures >1700 K was fully decomposed, while the CH4 in the final syngas originated from the pyrolysis of fuel particles at temperatures below 1400 K in the lower section of the reactor core. It is shown that the process efficiency was significantly reduced due to the C and H atoms bound in methane and soot.

Coupled modeling of irradiated fuel thermochemistry and gas diffusion during severe accidents

In this paper, a novel approach where irradiated fuel thermochemistry and gas release are coupled is presented in details and illustrated by the simulations of some tests of the VERCORS program characterized by increasing temperatures and varying gas composition in the furnace (oxidizing or reducing conditions). At each step of the tests, the oxidation/reduction of the nuclear fuel and the fission product chemical speciation are precisely assessed thanks to a thermochemical equilibrium calculation relying on the OpenCalphad thermochemical solver and on a built-in thermochemical database derived from the SGTE database and completed by a solid solution model for the U-O-fission product system. Fission product releases are estimated from the chemically reactive gases that form in the fuel (according to the thermochemical calculation) and from a gas diffusion model based on the equivalent sphere model. The gas diffusion model takes into account not only the noble gases available in the fuel prior to the test but also the chemically reactive gases that form during the test. It is shown that the proposed coupled approach provides a consistent estimation of fission product release (I, Te, Cs, Mo, Ba) during the VERCORS tests in spite of the simple gas diffusion mechanism considered in the simulations (no distinction between the fission products). The proposed coupled approach is used to test some thermochemical hypotheses to improve the calculated release of some fission products (Ba, Mo).

Ash transformation during single-pellet gasification of sewage sludge and mixtures with agricultural residues with a focus on phosphorus

The recovery of phosphorus (P) from sewage sludge ashes has been the focus of recent research due to the initiatives for the use of biogenic resources and resource recovery. This study investigates the ash transformation chemistry of P in sewage sludge ash during the co-gasification with the K-Si- and K-rich agricultural residues wheat straw and sunflower husks, respectively, at temperatures relevant for fluidized bed technology, namely 800 °C and 950 °C. The residual ash was analyzed by ICP­AES, SEM/EDS, and XRD, and the results were compared to results of thermochemical equilibrium calculations. More than 90% of P and K in the fuels were retained in the residual ash fraction, and significant interaction phenomena occurred between the P-rich sewage sludge and the K-rich ash fractions. Around 45–65% of P was incorporated in crystalline K-bearing phosphates, i.e., K-whitlockite and CaKPO4, in the residual ashes with 85–90 wt% agricultural residue in the fuel mixture. In residual ashes of sewage sludge and mixtures with 60–70 wt% agricultural residue, P was mainly found in Ca(Mg,Fe)-whitlockites and AlPO4. Up to about 40% of P was in amorphous or unidentified phases. The results show that gasification provides a potential for the formation of K-bearing phosphates similar to combustion processes.

The mineral transformation and molten behaviors of biomass waste ashes in gasification-melting process

Understanding the various ash transformation properties is vital for improving gasification behavior and optimizing industrial operation conditions during the gasification-melting process of biomass wastes. In this work, five typical biomass wastes were selected to investigate the slag property. The ash fusion process, mineral transformation and AAEMs solidification behaviors were performed and predicted by mineral transformation analysis and thermochemical calculation. The results indicated that ash fusion process contained sintering, swelling, bubbling and melting stages, which was related to ash chemical compositions. Besides, the ash flow temperature had a linear relationship with the basic-to-acid ratio of biomass waste ashes. High SiO2 content would lead to strong mineral crystallinity at high temperatures. The mineral transformation was also highly related to ash compositions. The complicated reactions of inorganic matters occurred when SiO2 content lied between 50 wt% and 70 wt%. For AAEMs solidification, the alkali was prone to react simultaneously with both SiO2 and Al2O3 to form eutectoid, and the range of 35–65 wt% for SiO2 + Al2O3 contents was beneficial for alkali solidification. All the obtained data was meaningful to provide a modifying reference for the efficient and clean utilization of various biomass wastes during gasification process.

DFT study of interaction of Palladium Pdn (n = 1–6) nanoparticles with deep eutectic solvents

In this study, we use density functional theory (DFT) calculations to investigate the stability, reactivity and interactions of Palladium Pdn (n = 1–6) nanoparticles with ChCl:U and ChCl:EG based deep eutectic solvents (DESs). We find that the DES … Pdn complexes are stabilized by two types of binding; Pdn-X anchoring bonds (X = N atom of –NH2 group in urea and [Cl]- anion) and Pdn…H-X (X = C, N and O) unconventional H-bonds. Analyses based on AIM, NBO, NCI, and EDA suggest that the anchoring bonds, which are electrostatic in nature are stronger than the unconventional H-bonds, which are van der Waals in nature. The Energy Decomposition Analysis reveals that the charge transfer plays an important role in the stability of DES…Pdn complexes. Thermochemical calculations, including enthalpy (ΔH) and free energy (ΔG), indicate that the formation of the DES…Pdn complexes is exothermic and occurs spontaneously. The binding energy (ΔEb) calculations show that the ChCl:U DES has a stronger interaction with the Pdn nanoparticles than their ChCl:EG DES counterparts. On the other hand, a similar trend for the ΔEb, ΔH and ΔG values of the complexes is observed with increasing nanoparticle size of Pdn (DES…Pd5> DES…Pd6> DES…Pd4> DES…Pd3> DES…Pd2> DES…Pd1). Our results show that the magnitude of charge transfer (ΔQ) value in the complexes follow the order observed for the ΔEb values. It is also observed that increasing the energy gap Eg values of the complexes decreases the ΔEb and ΔQ values of the complexes. The reactivity parameter calculations of the complexes show that the Eg and chemical hardness (η) values of ChCl:U…Pdn and ChCl:EG…Pdn complexes decrease with an increase in the nanoparticle size. Additionally, the global electrophilicity index (ω) values of the DES…Pdn complexes increase with an increase in the Pdn nanoparticle size, while no clear trend is seen for the chemical potential (μ) values of the complexes. The urea-based DES shows better suitability towards Pdn nanoparticles than the ethylene glycol-based DES. Overall, such DESs are potentially promising green solvents for nanoparticle synthesis and activity.

Methods for the determination of composition, mineral phases, and process-relevant behavior of ashes and its modeling: A case study for an alkali-rich ash

The mineral matter contained in feedstocks has a generally limiting impact on the process design of high-temperature conversion processes. In the present study, the composition, mineral phases, and process-relevant properties of ashes are investigated by different experimental and modeling methods, which were reviewed in the literature regarding the frequently applied methods. Various analyses are exemplarily performed for the ashes of a high-sodium coal from China, generated at temperatures of 150–950 °C. X-ray fluorescence (XRF) analysis, microwave-assisted inductively-coupled plasma optical emission spectrometry (MW-ICP-OES), and the same technique with electrothermal vaporization (ETV-ICP-OES) are applied to analyze the chemical composition of the bulk material. The chemical composition of the near-surface region is studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Mineral phases are analyzed by X-ray diffraction (XRD) and thermochemical calculations. The process-relevant ash fusion behavior is studied by a common ash fusion test (AFT) and thermomechanical analysis (TMA) and supported by thermochemical calculations. The different ashing temperatures have a recognizable impact on the composition, formation and transformation of mineral phases, and resulting ash fusion behavior, while each property is monitored by at least two different methods. For this purpose, a detailed analysis of the results achieved by the individual methods is performed. Finally, the results obtained by different methods for the same ash property are compared for monitoring the validity of the results and, for example, extracting additional information about the gas phase transfer of selected ash components.

Prediction of concentration of toxic gases produced by detonation of commercial explosives by thermochemical equilibrium calculations

An adverse effect resulting from explosive mine blasts is the production of toxic nitrogen oxides (NO and NO2) and carbon monoxide (CO). The empirical measurements of the concentration of toxic gases showed that it depends not only on the composition of an explosive and properties of its ingredients but also on several other parameters, such as volume of blasting chamber, explosive charge mass and design, confinement characteristics, surrounding atmosphere, etc. That explains why measured concentrations of toxic gases reported in literature significantly differ.In this paper, we discuss the possibility of theoretical prediction of the concentration of toxic gases by thermochemical equilibrium calculation applying two models: ideal detonation model and deflagration model. It can be demonstrated that thermochemical calculations can provide a good estimation of the measured concentrations and reproduce experimentally obtained effects of additives on the production of toxic gases. It was also found that the ideal detonation model applies to heavily confined explosive charges, while the deflagration model is more suitable for low detonation velocity explosives with light confinement.

Temperature and phase transitions of laser-ignited single iron particle

The combustion behavior of single laser-ignited iron particles is investigated. Transient particle radiant intensities at 850 nm and 950 nm are measured by post-processing recorded high-speed camera images using an in-house developed particle tracking program. Then, the time-resolved particle temperature is obtained based on two-color pyrometry. A plateau-like stage shortly after the ignition is repeatedly observed, and identified as iron particle melting by the measured temperature and the estimated melting time. Besides, an abrupt brightness jump near the end of combustion is observed for most burning particles, while a small portion of the particles (< 10%) show a second plateau-like stage instead. The particle temperature right after the brightness jump (1880±70 K) is almost identical to that during the second plateau-like stage. This temperature corresponds to two phase-change temperatures in the Fe-O phase diagram: i) L2 <=> Fe3O4 (s) at 1869 K (congruent melting) and ii) L2 <=> Fe3O4 (s) + O2 (g) at 1855 K (eutectic reaction), where L2 represents a liquid iron oxide. Based on this, the presence of the brightness jump (spear point) is explained by a sudden solidification of supercooled iron oxide droplets with an atomic O/Fe ratio larger than or close to 4/3. Particles’ near-peak temperatures are also measured based on time-integrated spectra. The results indicate that the near-peak temperature increases first fast and then slowly with an increase of oxygen concentration. At higher oxygen concentrations, smaller particles have a slightly lower temperature. The effect of particle size on the near-peak temperature is negligible at lower oxygen concentrations due to weaker radiation. The morphology of combusted particles is examined by micrography. Some burned particles appear as hollow thin-shell spheres at all adopted oxygen concentrations. Additionally, nano oxides are found at 13–51% oxygen concentrations. Less traces of nano oxides were observed at reduced oxygen concentrations. The nano-oxide formation mechanisms are analyzed based on thermochemical equilibrium calculations.

Computational examination of the kinetics of electrochemical nitrogen reduction and hydrogen evolution on a tungsten electrode

Elucidating the elementary kinetics of nitrogen reduction on transition metal surfaces can guide the search for materials capable of efficiently catalysing electrochemical ammonia synthesis at ambient conditions. Density functional theory calculations are used here to explore the elementary kinetics of nitrogen reduction and hydrogen evolution on W(110). All proton-electron transfer barriers are calculated at −0.7 V vs. SHE, where the cathodic potential is explicitly modelled using a solvation bilayer of water with hydronium ions. The protonation of adsorbed NH is determined to be rate-limiting for nitrogen reduction, with a barrier of 0.65 eV. The same reaction step is potential-limiting based on the thermochemistry of adsorbed intermediates only, showing that thermochemical calculations suffice to predict catalytic trends for nitrogen reduction. The largest barrier found for hydrogen evolution at high hydrogen coverage is 0.36 eV. Thus, hydrogen evolution is expected to dominate over nitrogen reduction on W(110) at negative potentials.

Algorithmic Modelling of Advanced Chlorination Procedures for Multimetal Recovery

In the course of developing an innovative process for CO2-optimised valuable metal recovery from precipitation residues accumulating in the zinc industry or nickel industry, the chlorination reactions were investigated. As the basis of small-scale pyrometallurgical experiments, the selected reaction systems were evaluated by means of thermodynamic calculations. With the help of the thermochemical computation software FactSage (Version 8.0), it is possible to simulate the potential valuable metal recovery from residual materials such as jarosite and goethite. In the course of the described investigations, an algorithmically supported simulation scheme was developed by means of Python 3 programming language. The algorithm determines the optimal process parameters for the chlorination of valuable metals, whereby up to 10,000 scenarios can be processed per iteration. This considers the mutual influences and secondary conditions that are neglected in individual calculations.

Determination of phase relations of the olivine\u2013ahrensite transition in the Mg2SiO4\u2013Fe2SiO4 system at 1740\xa0K using modern multi-anvil techniques

The phase relations of iron-rich olivine and its high-pressure polymorphs are important for planetary science and meteoritics because these minerals are the main constituents of terrestrial mantles and meteorites. The olivine–ahrensite binary loop was previously determined by thermochemical calculations in combination with high-pressure experiments; however, the transition pressures contained significant uncertainties. Here we determined the binary loop of the olivine–ahrensite transition in the (Mg,Fe)2SiO4 system at 1740 K in the pressure range of 7.5–11.2 GPa using a multi-anvil apparatus with the pressure determined using in situ X-ray diffraction, compositional analysis of quenched run products, and thermochemical calculation. Based on the determined binary loop, a user-friendly software was developed to calculate pressure from the coexisting olivine and ahrensite compositions. The software is used to estimate the shock conditions of several L6-type chondrites. The obtained olivine–ahrensite phase relations can also be applied for precise in-house multi-anvil pressure calibration at high temperatures.

Comparison of setups for measuring the viscosity of coal ash slags for entrained-flow gasification

A coal ash and a process slag from an entrained-flow gasifier were analyzed by two institutes in their respective workflow to compare viscosity measurement techniques under reducing conditions. Several analyses were carried out to characterize the samples, including X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDX). The results are compared to the phases predicted based on thermochemical calculations. A coal slag (S1) was analyzed as exhibiting Newtonian behavior by one institute, while it showed shear-thickening behavior at another institute due to crystallization. This was confirmed by XRD and SEM-EDX. In contrast to previous studies, the sample in this work was still glassy at a low shear rate. The phase compositions of the crystallized slags were in good agreement with thermochemical predictions. The process slag (S2) sample showed shear-thinning behavior but was of very high viscosity, meaning that the measurement was restricted by instrumental limitations. The chemical compositions of the slags obtained after viscosity measurements indicated contamination with crucible material (Mo) for S1, while the composition of S2 was the same before and after viscosity measurements. The overall relative difference in the measurements considering both measurement routines and both samples was ±22%.

Following the Lithium: Tracing Li-bearing Molecules across Age, Mass, and Gravity in Brown Dwarfs

Abstract Lithium is an important element for the understanding of ultracool dwarfs because it is lost to fusion at masses above ∼68 M J. Hence, the presence of atomic Li has served as an indicator of the nearby H-burning boundary at about 75 M J between brown dwarfs and very low mass stars. Historically, the “lithium test,” a search for the presence of the Li line at 670.8 nm, has been a marker if an object has a substellar mass. While the Li test could, in principle, be used to distinguish masses of later-type L–T dwarfs, Li is predominantly no longer found as an atomic gas but rather a molecular species such as LiH, LiF, LiOH, and LiCl in cooler atmospheres. The L- and T-type dwarfs are quite faint at 670 nm and thus challenging targets for high-resolution spectroscopy. But only recently have experimental molecular line lists become available for the molecular Li species, allowing molecular Li mass discrimination. Here we generated the latest opacity of these Li-bearing molecules and performed a thermochemical equilibrium atmospheric composition calculation of their abundances. Finally, we computed thermal emission spectra for a series of radiative–convective equilibrium models of cloudy and cloudless brown dwarf atmospheres (with T eff = 500–2400 K and log g = 4.0 – 5.0 ) to understand where the presence of atmospheric lithium-bearing species is most easily detected as a function of brown dwarf mass and age. After atomic Li, the best spectral signatures were found to be LiF at 10.5–12.5 μm and LiCl at 14.5–18.5 μm. Also, LiH shows a narrow feature at ∼9.38 μm.

Physico-Chemical Properties and Quantum Chemical Calculation of 2-methoxy-4-(prop-2-en-1-yl) phenol (EUGENOL)

Physico-chemical properties plays an important role in determining toxicity of a material hence were calculated using acdlab/chemsketch and the data predicted is generated using ACD/Labs Percepta Platform - PhysChem Module. Gaussian 09, RevisionA.01, software package was used for the theoretical quantum chemical calculations of 2-methoxy-4-(prop-2-en-1-yl) phenol commonly called Eugenol. DFT/B3LYP/6-311G (d, p) basis was used to perform geometric optimization and vibrational frequency determination of the molecule. The statistical thermochemical calculations of the molecule were done at DFT/B3LYP/6-311G (d, p) basis set to calculate the standard thermodynamic functions: heat capacity (CV), entropy (S) and Enthalpy (E). DFT/B3LYP/6-311G (d, p) basis set was used to calculate the various NLO properties like dipole moment (µ), mean linear polarizability (α), anisotropic polarizability (Δα), first order hyperpolarizability (β), second order hyperpolarizability (γ) in terms of x, y, z components for Eugenol (2-methoxy-4-(prop-2-en-1-yl) phenol. Same basis set was used to carry out Mulliken population analysis. UV-Visible absorption spectra, ECD spectra, electronic transitions, vertical excitation energies and oscillator strengths of Eugenol (2-methoxy-4-(prop-2-en-1-yl) phenol) were computed by Time Dependent DFT (TD-DFT) method using the same basis set. FMO analysis, Molecular electrostatic potential study was also done using the same basis set.

Paving the way to the sustainable hydrogen storage: Thermochemistry of amino-alcohols as precursors for liquid organic hydrogen carriers

The absolute vapour pressures of four amino-alcohols were measured using the transpiration method. A consistent set of standard molar enthalpies of vaporization for eighteen amino-alcohols was evaluated using empirical and structure–property correlations. The averaged values of vaporization enthalpies are recommended as reliable benchmark properties for thermochemical calculations of the energetics of chemical reactions including synthesis of alkyl-substituted pyrazines, compounds considered as seminal liquid organic hydrogen carriers (LOHC)