Abstract:

The migration velocity, the migratory activation energy and the action of molecular motion on migration were researched for five alkanes in the gas-solid chromatography of N₂/GDX-101 system. Maxwell distribution of energy which originally shows the molecule fraction of molecular translation energy exceeding E, was used for expressing the time fraction of the translation energy exceeding E. The kinetic energy of rotation and vibration was expressed by the times of kT/2 in the light of the principle of equiparation of energy, to modify the ideal equation. The migratory activation energy(E) which is calculated with the rate equation, could well explain the migration velocity. The kinetic energy of rotation and vibration observably influences E. These properties were also authenticated with the estimate of statistical thermodynamics. The calculation showed that E was obviously smaller than the desorption enthalpy(ΔH_Desorption). The solute migration might not reach the state of desorption. The solute driven by mobile phase should mainly slip under the state of adsorption.

Key words: Molecular ehermoclynamic movement, Migratory activation energy, Maxwell distribution of energy, Principle of equiparation of energy, Gas-solid chromatography, Slip mechanism