Grupo de Investigación PLATON
Universidad de Zaragoza

Thermophysical properties

Our main interest in this research line is the determination of thermophysical and transport properties of liquid systems, their modelling and theoretical treatment (including pure liquids and binary and ternary mixtures).

The liquid state shows a great variety of behaviours because it can be formed by a wide range of substances. Moreover, it has great interest from a theoretical perspective and also for its practical applications in industrial process design, since many chemical reactions and other processes (transport, separation, etc.) take place in this state. For these reasons, it is so important to obtain a great variety of accurate experimental data and the development of theoretical models that allow us to understand, at least partially, the phenomena occurring in the liquid state.

The main objectives in this research line are:

  • Determination of thermophysical properties of liquid systems, correlation and treatment of the data obtained. The properties under study are: liquid-vapour equilibrium both in isobaric and isothermal conditions, density and p-V-T behaviour, speed of sound propagation, thermal effect, heat capacity, surface tension, refractive index, permittivity, conductivity and viscosity. These properties are incorporated into databases used for the quantitative design of industrial processes. Moreover, they are also used for the development, test and improvement of Group Contribution Models (UNIFAC, Predictive Soave-Redlich-Kwong, Volume Translated Peng-Robinson, etc.).
  • Qualitative study of intermolecular forces (specific and non-specific interactions) and structural effects.
  • Quantitative study of different properties, using a variety of theoretical models such as the equation of state Statistical Associating Fluid Theory with Variable Range potential (SAFT-VR).
  • Computation of thermodynamic, structural and dynamic properties of the studied systems, making use of theoretical models (HF, DFT) and computer simulation (Molecular Dynamics).

Our activity in this research line comprises two great groups of systems:

  • Non-electrolytic compounds and their mixtures. We perform a systematic study of properties of substances with interest for industry (solvents, compounds derived from biomass, etc.) and their binary and ternary mixtures. The systems under study are carefully chosen to obtain information about the different effect that takes place during the mixing process. Complementary to the determination of experimental data we also use theoretical models to predict the behavior of these systems.
  • Ionic liquids and mixtures organic solvent + ionic liquid. Ionic liquids are salts of organic compounds that are liquid in a wide range of temperatures above and below ambient temperature; moreover they are stable to humidity. The study of that kind of compounds is the answer to the recent requirements of the Chemical Industry: finding alternative solvents to the compounds in use, with better performance and lower ambient impact. Ionic liquids are a powerful alternative to traditional organic solvents thanks to their great technical and scientific interest and their particular physicochemical properties (good solvents for most of the organic and inorganic compounds, very low volatility, high thermal stability, wide electrochemical window, nonflammable, no toxic, no abrasive, can be easily recycled and, in many cases, they are potent catalysts).

Laboratorio de Microscopias Avanzadas Instituto de Ciencia de Materiales de Aragón Instituto de Nanociencia de Aragón Facultad de Ciencias Universidad de Zaragoza Departamento de Química Física Universidad de Zaragoza