Determining the transport diffusivity from intracrystalline concentration profiles

  • Autor:

    Heinke, L. / Chmelik, C. / Kärger, J. (2008)
  • Quelle:

    Studies in Surface Science and Catalysis 174 (2008), 607–610
  • Datum: 2008

  • Heinke, L. / Chmelik, C. / Kärger, J. (2008): „Determining the transport diffusivity from intracrystalline concentration profiles“. In: Studies in Surface Science and Catalysis 174 (2008), 607–610

Abstract

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Transport properties of guest molecules are of major importance for many applications of nanoporous materials. The concentration profiles evolving during uptake and release experiments allow the determination of the transport diffusivity by different approaches with various boundary conditions and varying accuracy.

We show that for one-dimensional mass transport the transport diffusivity may be directly calculated by an equation based on Fick's 1st law. This method is independent of special boundary conditions, as required for Boltzmann's integration method, and provides a better accuracy compared to the previously reported approach by direct application of Fick's 2nd law.