The strength of energetic materials is one of the principal parameters to express their performance. Two new methods were introduced for the prediction of the strength of CaHbNcOd energetic materials through the Trauzl test. They are based on elemental composition and the condensed or gas phase heats of formation of energetic compounds. The model is based on the gas phase heat of formation, uses the group additivity method and requires only the molecular structure of the desired energetic compound. These methods provide more reliable predictions as compared to the best available theoretical methods. Some of the benefits of these new models are their accuracy, precision, simplicity, and low price.

An improved simple method is presented for calculation of the detonation velocity of CHNO and CHNOFCl explosives, as well as non-ideal explosives containing aluminum (Al) and ammonium nitrate (AN) additives. In contrast to the available complex computer codes, where the estimated detonation velocities of non-ideal explosives for equilibrium and steady state calculations show significant differences from the measured data, this simple method gives more reliable results. Suitable decomposition paths are suggested in which the partial interaction of Al with the gaseous products and the decomposition of AN are assumed for composite explosives containing Al/AN additives. The predicted detonation velocities using the new method are good compared to those from one of the well-known empirical methods and from computer codes using full and partial equilibrium of Al/AN.

A property of central interest for theoretical study of nanoconfined fluids is the density distribution of molecules. The density profile of the hard-sphere fluids confined within nanoslit pores is a key quantity for understanding the configurational behavior of confined real molecules. In this report, we produce the density profile of the hard-sphere fluid confined within nanoslit pores using the fundamental-measure density-functional theory (FM-DFT). FM-DFT is a powerful approach to studying the structure and the phase behavior of nanoconfined fluids. We report the computational procedure and the calculated data for nanoslits with different widths and for a wide range of hard-sphere fluid densities. The high accuracy of the resulting density profiles and optimum grid-size values in numerical integration are verified. The data reveal a number of interesting features of hard spheres in nanoslits, which are different from the bulk hard-sphere systems. These data are also useful for a variety of purposes, including obtaining the shear stress, thermal conductivity, adsorption, solvation forces, free volume and prediction of phase transitions.

The condensed phase standard enthalpy of formation of energetic materials plays important role in assessment of their detonation and combustion performance. High nitrogen content materials can be considered as high-performance energetic materials because they have relatively high positive values of the condensed phase heat of formation. Two new models were presented for prediction of the condensed phase standard enthalpy of formation for compounds containing more than 50 % of nitrogen. The new models need the calculated values of gas phase standard enthalpies of formation, which were calculated on the basis of B3LYP/6-31G* method or the semiempirical PM6 method. Moreover, the effects of some structural parameters, such as hydrogen bonding, were considered in order to increase the accuracy of models. Reliability of the new models has been confirmed as compared with several of the best and new available methods.[a] Dr.

The structure and properties of fluids confined in nanopores may show a dramatic departure from macroscopic bulk fluids. The main reason for this difference lies in the influence of system walls. In addition to the entropic wall effect, system walls can significantly change the energy of the confined fluid compared to macroscopic bulk fluids. The energy effect of the walls on a nanoconfined fluid appears in two forms. The first effect is the cutting off of the intermolecular interactions by the walls, which appears for example in the integrals for calculation of the thermodynamic properties. The second wall effect involves the wall-molecule interactions. In such confined fluids, the introduction of wall forces and the competition between fluid-wall and fluid-fluid forces could lead to interesting thermodynamic properties, including new kinds of phase transitions not observed in the macroscopic fluid systems. In this article, we use the perturbative fundamental measure density functional theory to study energy effects on the structure and properties of a hard core two-Yukawa fluid confined in a nanoslit. Our results show the changes undergone by the structure and phase transition of the nanoconfined fluids as a result of energy effects.