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Four binary mixtures with potential for stabilizing energetic materials have been investigated. The phase diagrams of N-(2-methoxyethyl)-p-nitroaniline þ diphenylamine, N-(2-methoxyethyl)-p-nitroaniline þ N- (2-acetoxyethyl)-p-nitroaniline, N-(2-methoxyethyl)-p-nitroaniline þ 2-nitrodiphenylamine, and N-(2- methoxyethyl)-p-nitroaniline þ 1,3-diethyl-1,3-diphenylurea have been determined by differential scanning calorimetry. All systems display a simple eutectic behavior. Consistency tests have been applied to inspect the quality of the SLE data, showing very satisfactory quality factors. The SLE data have also been correlated by Wilson and NRTL models. The employed equations calculated the equilibrium temperatures with a root mean square deviations varying from 1.37 to 2.29 K. These models have been applied to compute the excess thermodynamic functions as well, giving highly comparable values for a further qualitative and quantitative analysis. The results showa positive deviation fromideality for all the investigated systems due to the dominant effect of the self-association molecules. The XRD studies revealed the existence of weak interactions between the components in the formed eutectics and suggested that they are mechanical systems. The authors are grateful for the financial support of this research from Ecole Militaire Polytechnique (Doctoral Training Program) and Project POCI-01-0145-FEDER-006984 (Ref. FCT UID/EQU/50020/2019) e Associate Laboratory LSRE-LCM e funded by European Regional Development Fund (ERDF) through COMPETE2020 e Programa Operacional Competitividade e Internacionalização (POCI) e and by national funds through FCT e Fundação para a Ciência e a Tecnologia I.P. info:eu-repo/semantics/publishedVersion

Biofuels have attracted considerable attention for current and future utilization because of their benefits as promising alternative, ecological and economical viable fuels, with particular reference to biodiesel and alcohols. In order to use biodiesel in diesel engines, the volumetric and transport properties of the fuel (i.e. density and viscosity) must be improved since they affect spray properties, atomization and combustion processes of a fuel. In addition, the derived thermodynamic magnitudes, such as isothermal coefficient and isobaric thermal expansion coefficient, greatly influence the atomization process and, consequently, the fuel consumption of diesel engines. Therefore, knowledge of these properties at different pressures and temperatures is important in order to predict and improve the performance of diesel engines. Densities, viscosities, sound velocities and refractive indices of pure components: 1-butanol, 1-propanol, ethyl laurate, ethyl linoleate, ethyl myristate, ethyl oleate, methyl laurate and n-hexadecane were measured at temperatures T= (293.15 to 343.15) K and atmospheric pressure. The measured values were compared to several available literature data, and good agreement was noticed: an overall absolute average percentage deviation (AAD) of 0.04%, 0.07%, 3 % and 0.1% for density, speed of sound, viscosity and refractive index data, respectively. Besides that, densities, viscosities, speeds of sound and refractive indices of ternary mixture ethyl oleate + n-hexadecane + 1-butanol (3), and for the corresponding binary mixtures: ethyl laurate + 1- propanol, ethyl oleate + 1-butanol, ethyl oleate + 1-propanol, ethyl oleate + n-hexadecane, nhexadecane + 1-butanol and n-hexadecane + 1-propanol were measured in the temperature range T= (293.15 to 343.15) K at atmospheric pressure. The measurements were performed on an Anton Paar DSA 5000 M density and sound velocity meter, Anton Paar SVM 3000 digital viscometer, and Anton Paar RXA 156 refractometer. From the experimental data, a number of thermodynamic parameters were also calculated, namely, excess molar volumes (VE), viscosity deviation functions (∆), deviations in refractive index (∆nD), excess molar Gibbs energy of activation of viscous flow (∆G*E) and deviation in isentropic compressibility (∆κs). The binary and ternary properties are then correlated as a function of the mole fraction by using the Redlich–Kister and Nagata and Tamura equations, respectively, and then used to analyze molecular interactions present in the mixtures... Biogoriva su privukla značajnu paţnju, kako za trenutnu, tako i za buduću upotrebu zahvaljujući svojim prednostima kao obećavajućim alternativnim, ekološkim i ekonomičnim gorivima, a posebno se ističu biodizel i bioalkoholi. Da bi se biodizel koristio u dizel motorima moraju mu se poboljšati volumetrijska i transportna svojstva (tj. gustina i viskoznost), jer utiču na raspršivanje, atomizaciju i sagorevanje goriva. Pored toga, izvedene termodinamičke veličine, kao što su izotermska stišljivost i izobarni koeficijent termičkog širenja, značajno utiču na proces atomizacije, a samim tim i na potrošnju goriva u dizel motorima. Stoga je poznavanje ovih svojstava pod različitim pritiscima i temperaturama vaţno kako bi se predvideo i poboljšao rad dizel motora. Gustine, viskoznosti, brzine zvuka i indeksi refrakcije čistih komponenti: 1-butanola, 1-propanola, n-heksadekana, etil oleaat, etil linoleata, etil laurata, etil miristata i metil laurata su mereni na temperaturama T = (293,15 do 343,15 ) K pri atmosferskom pritisku. Izmerena vrednosti su poreĎene sa nekoliko dostupnih literaturnih podataka, I primećeno je dobro slaganje, ukupno prosečno pocentualno odstupanje (AAD) je bilo oko 0,04%, 0,07%, 3% i 0,1%, redom za gustine, brzine zvuka, viskoznosti i indekse refrakcije. Pored toga, merene su i gustine, viskoznosti, brzine zvuka i indeksi refrakcije ternerne smeše etil oleat + n-heksadekan + 1-butanol , i odgovarajućih binarnih smeša etil oleat + 1-butanol, etil oleat + 1-propanol, etil oleat + n-heksadekan, etil laure + 1-propanol, n-heksadekan + 1-butanol i nheksadekan + 1-propanol u temperaturnom opsegu T = (293,15 do 343,15) K sna atmosferskom pritisku. Merenja su izvršena na Anton Paar DSA 5000 M ureĎaju za merenje gustine i brzine zvuka, Anton Paar SVM 3000 digitalnom viskozimetru i Anton Paar RKSA 156 refraktometru. Iz eksperimentalnih podataka su, takoĎe, izračunai I brojni termodinamički paramtetri, kao na pr. Dopunska molarna zapremina (VE), odstupanje viskoznosti (∆), odstupanje indeksa refrakcije (∆nD), dopunska molarna Gibsova energija aktivacije viskoznog toka (∆G*E) i višak izentropske kompresibilnosti (∆κs). Binarna i ternarna svojstva su nakon toga korelisana u zavisnosti od molekulskih sastava primenom Redlih-Kister i Nagata i Tamura jednačina, redom, a potom su korištena za analizu molekulskih interakcija unutar smeša...

Differential scanning calorimetry (DSC) is used to investigate the thermal properties of N-(2-ethanol)-p-nitroaniline+N-(2-acetoxyethyl)-p-nitroaniline, and their binary systems. The experimental results demonstrate that the studied binary system presents a simple eutectic behavior and the corresponding mole fraction(xeu)ofN-(2-ethanol)p-nitroaniline at the eutectic point is 0.5486, whereas the temperature (Teu) is found to be equal to 363.6 K. The quality of the solid–liquid equilibria (SLE) data has been checked by thermodynamic consistency tests, presenting good quality factor. The SLE data have been correlated by means of Wilson, NRTL, and UNIQUAC equations. The three models describe satisfactorily the phase diagram as the root-mean-square deviations for the equilibrium temperatures vary from 1.25K to 2.07K. Nevertheless, the Wilson model provides the best correlation results. The three equations have also been used to compute excess thermodynamic functions viz. excess Gibbs energy, enthalpy and entropy. The obtained results revealed a sensitive positive deviation to ideality thus demonstrating the nature of the interactions between the compounds forming the mixture. Microstructural studies have been carried out by FTIR, XRD and optical microscopy showing weak molecular interactions for the eutectic mixture. info:eu-repo/semantics/publishedVersion

Solid-liquid equilibria (SLE) data for two binary organic mixtures of N-(2-methoxyethyl)-p-nitroaniline+Nethyl- 4-nitroaniline (S1) and N-(2-ethanol)-p-nitroaniline+N-ethyl-4-nitroaniline (S2) have been measured using differential scanning calorimeter to build the corresponding solid-liquid phase diagrams. The quality of the SLE data has been checked by consistency tests, presenting good quality factors for both systems. Simple eutectic behavior has been observed for these systems with the presence of a solid-solid transition for S2. The SLE data have been correlated by means of Wilson, NRTL, and UNIQUAC equations. The used models calculate the equilibrium temperatures very satisfactorily. The best modeling results were obtained using the Wilson equation with a root mean square deviation between experimental and calculated values for S1 and S2 of 1.15 and 1.99, respectively. The Wilson, NRTL, and UNIQUAC equations have also been used to compute excess thermodynamic functions viz. excess Gibbs energy, enthalpy, and entropy. The obtained results demonstrated a moderate positive deviation to ideality for S1, and a strong positive deviation for S2, unveiling the nature of the interactions between the compounds forming each mixture. In addition, microstructural studies have been carried out by FTIR, XRD and optical microscopy. Weak molecular interactions have been shown for the eutectic compositions. Jackson’s roughness parameter was calculated and found to be greater than 2, suggesting the faceted morphology with irregular structures. The authors are grateful for the financial support of this research from Ecole Militaire Polytechnique (Doctoral Training Program) and from Associate Laboratory LSRE-LCM, Instituto Politécnico de Bragança (projectPOCI-01-0145-FEDER-006984) funded by European Regional Development Fund (ERDF) through COMPETE2020 –Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundaçãopara a Ciência e a Tecnologia. C.M.S.S. Neves thanks FCT for the postdoctoral grant SFRH/BPD/ 109057/2015. info:eu-repo/semantics/publishedVersion

En este trabajo se muestra el uso de la técnica fotoacústica láser para estudiar la señal acústica generada por un láser de Nd-YAG Q-Switch en soluciones líquidas usando diferentes proporciones de etanol, metanol, acetona y agua destilada en mezclas binarias. Para este fin se trabajó con el láser enmascarado por un pinhole de aproximadamente 0,35 mm de diámetro; se realizó la adquisición de la señal de presión mediante un transductor PZT con amplificador tomando, con un osciloscopio digital de 300 MHz de ancho de banda, el promedio sobre 64 muestras para diferentes distancias entre el haz láser y el PZT. En un trabajo previo se determinó la velocidad del sonido con una precisión del 1%, estudiándose los cambios en función de la proporción de los líquidos. En este se analiza cómo varía el máximo de la señal fotoacústica según la proporción de las componentes de la mezcla. Se comparan los resultados con el modelo de Tam y Patel para estos líquidos y la relación con las propiedades termodinámicas en exceso, responsables también de los cambios de velocidad del sonido In this paper we present the use of the photoacoustic laser technique to study the acoustic signal generated by a Q-Switched Nd-YAG laser on liquid solutions using different proportions of distilled water, ethanol, methanol and acetone in binary mixtures. To this end, a pinhole was used to reduce the beam diameter from the original to approximately 0,35 mm; the signal acquisition was done by means of a PZT transducer and then amplified. A 300MHz digital oscilloscope averages 64 signals, taken for diferent distances between the laser beam and the PZT. In a previous work, the speed of sound was determined with aprecision of 1%, studying their changes according to the composition of the mixture. Here, we analize how the maximum of the photoacoustic signal changes according to the proportion of the mixture components. The results are compared to the Tam and Patel's model for these liquids, and the relation to the excess thermodynamic proporties, also responsible for the changes in the speed of sound Fil: Pardini, P. A.. Universidad Nacional Del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Físca Arroyo Seco (UNCPBA-IFAS). Buenos Aires. Argentina Fil: Iriarte, D. I.. Universidad Nacional Del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Físca Arroyo Seco (UNCPBA-IFAS). Buenos Aires. Argentina Fil: Pomarico, J. A.. Universidad Nacional Del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Físca Arroyo Seco (UNCPBA-IFAS). Buenos Aires. Argentina Fil: Ranea-Sandoval, H. F.. Universidad Nacional Del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Físca Arroyo Seco (UNCPBA-IFAS). Buenos Aires. Argentina

The basis is described Of a method for analyzing the dependence of rate constants on solvent composition using Kirkwood-Buff integral functions. The background to the treatment is examined with reference to the analysis of thermodynamic properties of binary aqueous mixtures. Procedures are outlined for combining this information and kinetic data to yield parameters characterizing interactions between solutes (i.e. initial and transition states) and the components of a binary aqueous solvent mixture. These calculations yield information concerning the affinities of solutes for components of the solvent mixture and hence describing the phenomenon of preferential solvation. Examples are quoted using kinetic data describing reactions involving organic and inorganic substances.

Department of Chemistry, Agra College, Agra-282 002, Uttar Pradesh, India E-mail : mukhtarsingh2003@rediffmail.com Manuscript received 18 November 2008, revised 22 June 2009, accepted 26 June 2009 Densities and viscosities of binary liquid mixtures of ethylenediamine with polar and non-polar solvents, viz. methyl alcohol, ethyl alcohol, n-propyl alcohol, n-butyl alcohol, acetone, methyl ethyl ketone, carbon tetrachloride, benzene and toluene have been measured at 293.15, 303.15 and 313.15 K. From density and viscosity data the values of viscosity deviations (0.11) and the thermodynamic excess properties viz. the excess molar volume (VE) and the excess Gibbs free energy of activation of viscous flow (∆G#E) have been determined. The values of ∆η, VEand ∆G#E have been fitted to Redlich-Kister polynomial equation to estimate the binary coefficients and standard deviation between the experimental and theoretical (calculated) values. From the small magnitude of the values of standard deviation it is concluded that the experimental values of ∆η, VEand ∆G#E compare fairly well with the theoretical values predicted by Redlich-Kister equation. The effect of increasing temperature on the values of ∆η, VEand ∆G#E as well as the nature of molecular interactions between the mixing components of the binaries has also been discussed.

Dynamic viscosities (eta) and densities (rho) of dilute solutions of glycerol trioleate + chloroform, at 10, 15, 20, 25,and 30 degrees C, and of glycerol trioleate + octane, + p-xylene, + toluene, at 20, 25, 30, 35, and 40 degrees C, were measured. The dynamic viscosities and the excess volumes were correlated with the composition and temperature through empirical relations. The standard deviations from the derived viscosity equation were of the same order of magnitude as the experimental uncertainties. The excess volumes (V-E) have been derived from the density measurements. V-E values were positive for the glycerol trioleate + chloroform system and negative for the other mixtures over the entire range of mole fractions covered in this study. The departure from the ideal behavior is explained on the basis of specific interactions between the components in these mixtures. Journal of Chemical and Engineering Data

The basis is described Of a method for analyzing the dependence of rate constants on solvent composition using Kirkwood-Buff integral functions. The background to the treatment is examined with reference to the analysis of thermodynamic properties of binary aqueous mixtures. Procedures are outlined for combining this information and kinetic data to yield parameters characterizing interactions between solutes (i.e. initial and transition states) and the components of a binary aqueous solvent mixture. These calculations yield information concerning the affinities of solutes for components of the solvent mixture and hence describing the phenomenon of preferential solvation. Examples are quoted using kinetic data describing reactions involving organic and inorganic substances.