Assessing Guest Diffusivities in Porous Hosts from Transient Concentration Profiles

作者:Heinke Lars*; Tzoulaki Despina; Chmelik Christian; Hibbe Florian; van Baten Jasper M; Lim Hyuna; Li Jing; Krishna Rajamani; Kaerger Joerg
来源:Physical Review Letters, 2009, 102(6): 065901.
DOI:10.1103/PhysRevLett.102.065901

摘要

Using the short-chain-length alkanes from ethane to n-butane as guest molecules, transient concentration profiles during uptake or release (via interference microscopy) and tracer exchange (via IR microimaging) in Zn(tbip), a particularly stable representative of a novel family of nanoporous materials (the metal organic frameworks), were recorded. Analyzing the spatiotemporal dependence of the profiles provides immediate access to the transport diffusivities and self-diffusivities, yielding a data basis of unprecedented reliability for mass transfer in nanoporous materials. As a particular feature of the system, self- and transport diffusivities may be combined to estimate the rate of mutual passages of the guest molecules in the chains of pore segments, thus quantifying departure from a genuine single-file system.

  • 出版日期2009-2-13
  • 单位rutgers