TY - JOUR A1 - Hoinkis, E. A1 - Röhl-Kuhn, Barbara T1 - Application of percolation theory to the drainage of liquid nitrogen from mesoporous silica xerogel gelsil 50 JF - Langmuir N2 - Previous in situ small-angle neutron scattering studies of nitrogen adsorption and desorption at 78 K on the mesoporous silica xerogels Gelsil 50 and Gelsil 75 revealed the formation of ramified clusters of vapor-filled pores on desorption, which is characteristic for a percolation process. In the present work, we check whether the adsorption/desorption isotherm data for a monolithic sample of Gelsil 50 can be analyzed in terms of a bond-percolation model. Three powder samples were studied too. Percolation probability data are presented and the effects of heterogeneous nucleation, finite size, and surface clusters on drainage from Gelsil 50 are addressed. The mean coordination number was derived. The results of the analysis are discussed with respect to recent theoretical work for interactions of fluids with complex pore systems. The monolithic sample and a powder sample were characterized by small-angle neutron scattering data. KW - Percolation Theory KW - Adsorption KW - Desorption KW - Silica Xerogel Gelsil 50 PY - 2005 SN - 0743-7463 SN - 1520-5827 VL - 21 IS - 16 SP - 7366 EP - 7372 PB - American Chemical Society CY - Washington, DC AN - OPUS4-12523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -