Related Experiment Video
Updated: Mar 30, 2026

In Situ High Pressure Hydrogen Tribological Testing of Common Polymer Materials Used in the Hydrogen Delivery Infrastructure
Published on: March 31, 2018
Transport properties of hydrogen-helium mixtures at extreme density and temperature conditions
Dafang Li1, Cong Wang1,2, Wei Kang2
1Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, People's Republic of China.
Abstract:
We perform a systematic study of hydrogen-helium mixtures using quantum molecular dynamics (QMD) with a focus on the equations of state and structural and transport properties such as electrical conductivity, diffusion, and viscosity at conditions of giant planet interiors of 0.2∼2.3 g/cm(3) and 1000∼80,000 K for a typical helium mass fraction of 0.245. The H-He separation is found at low temperatures by analyzing the trajectories and pair distribution functions. We show that the diffusion coefficients exhibit transitions from kinetics- to potential-, and then to demixing-dominated regimes. In addition, we identify the discontinuity feature of optical absorption of a H-He mixture at low density and temperature conditions, which results from the change from an intraband to an interband transition. The Stokes-Einstein relation between the diffusion and viscosity coefficients is also discussed.
More Related Videos
Related Concept Videos
Applications of the Ideal Gas Law: Molar Mass, Density, and Volume
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Ideal Solutions or Mixtures
Escape Velocities of Gases
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
The Thermodynamics of Mixing

