Percorrer por autor "Khimeche, Kamel"
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- Experimental and modeling studies of binary organic eutectic systems to be used as stabilizers for nitrate esters-based energetic materialsPublication . Chelouche, Salim; Trache, Djalal; Pinho, Simão; Khimeche, KamelFour 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.
- Solid + liquid equilibria and molecular structure studies of binary mixtures for nitrate ester's stabilizers: Measurement and modelingPublication . Chelouche, Salim; Trache, Djalal; Neves, Catarina M.S.S.; Pinho, Simão; Khimeche, Kamel; Benziane, MokhtarSolid-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.
- Solid–Liquid Phase Equilibria, Molecular Interaction and Microstructural Studies on (N-(2-ethanol)-p-nitroaniline + N-(2-acetoxyethyl)-p-nitroaniline) Binary MixturesPublication . Chelouche, Salim; Trache, Djalal; Pinho, Simão; Khimeche, Kamel; Mezroua, Abderrahmane; Benziane, MokhtarDifferential 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.