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09:05
Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials
Published on: May 15, 2015
Thermodynamic behaviour of supercritical matter
Dima Bolmatov1, V V Brazhkin, K Trachenko
1School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
Nature Communications
|August 17, 2013
Summary
Supercritical fluids exhibit a surprising specific heat crossover, challenging the notion of their homogeneity. A new thermodynamic theory explains this behavior, improving predictions without free parameters.
Area of Science:
- Thermodynamics
- Physical Chemistry
- Materials Science
Background:
- Supercritical fluids, known since 1822, have diverse applications but lack complete theoretical understanding.
- This theoretical gap hinders further industrial adoption of supercritical fluid technology.
Purpose of the Study:
- To investigate the thermodynamic properties of the supercritical state.
- To address the limitations in theoretical understanding hindering industrial deployment.
Main Methods:
- Studied thermodynamic properties of supercritical fluids.
- Developed a new theory for system thermodynamics above a specific crossover point.
- Validated the theory by comparing calculated and experimental specific heat data.
Main Results:
- Discovered a specific heat crossover between two distinct regimes in the supercritical state.
- Formulated a theory where energy and heat capacity depend only on minimal longitudinal mode length.
- Achieved excellent agreement between theoretical calculations and experimental data for specific heat, with no free-fitting parameters.
- Derived a power law and analyzed supercritical scaling exponents above the Frenkel line.
Conclusions:
- The supercritical state is not as physically homogeneous as previously perceived.
- The developed theory accurately describes supercritical thermodynamics, offering a new framework for understanding and application.
- This research advances the theoretical foundation for supercritical fluid applications.
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