Computational Thermodynamic Analysis of Nanostructured Materials for Protective Coatings

Abstract

Nanostructured materials have gained a lot of importance in the latest technologies due to their amazing mechanical, thermal, and even nuclear properties. Either used as classic protective coatings or particle detectors, nanostructured materials require special synthesis methods, from physical or chemical vapour deposition, flame synthesis to plasma processing. The complex phenomena accompanying their synthesis required the deep study of the thermodynamic parameters of such systems, with special emphasis on a theoretical approach which is independent to the synthesis method and generally applicable. The complex mathematical description of such phenomena and the solution to the thermodynamic functions of the system, achieved in many cases by numerical methods, was often done by strong commercial codes. Despite the efforts, many of the predicted synthesis parameters did not match experimental determinations, and furthermore, conducted to confusing and even wrong results regarding especially the pressure and temperature range required to obtain the quality materials. The present work aims to draw a comparative computational analysis of nanostructured materials, indicating not only some commercial code results, but also the differences in softwares, methods, theoretical approach and conclusions. Both similarities and differences are underlined by the numerical and graphical solutions, as offered by various commercial codes, revealing strong and weak aspects in thermodynamic considerations. The output of such a computational thermodynamic analysis doesnt depend on the synthesis method, but on the assumptions done and the materials under evaluation, and presents a good concordance with many experimental data, either obtained during authors work or literature-reported. The study is useful when needing the synthesis parameters, such as temperature, system and component pressure, feedstock composition, the degree of freedom analysis, the Gibbs free energy, the driving force, the phase diagrams, the pressure-temperature or pressure-volume graph. Taking into account the balance between assumptions, accuracy, and effective nanostructured material, one has to choose the most suitable commercial code and approach in order to obtain the a-priori thermodynamic characterization of the system.