Characterization of sol–gel derived membranes and zeolite membranes by nanopermporometry

Exposing the Molecular Sieving Architecture of Amorphous Silica Using Positron Annihilation Spectroscopy

“…Alternatively, researchers have utilized nanoperm porosimetry to quantify micropore size distributions, [5,24] which may be a better approach than gas adsorption. Water is the most convenient molecule for this process due to its small size and high vapor pressure, however, water can alter the structure of hydrophilic microporous silica [22] while surface hydrophobicity may also influence results.…”

Hybrid Materials for Molecular Sieves

“…A method proposed and applied by Tsuru and coworkers is to determine at which relative pressure of the condensable gas the inert gas flux is only 50 % of its value under dry conditions. Using the original Kelvin equation, an "effective Kelvin radius" (rather than a complete pore size distribution) is calculated from the data (Tsuru et al 2003). Typically compounds like water and helium may be used in these experiments as condensable vapor and inert gas, respectively, because of their small kinetic diameters, which make them suitable for microporous matrices.…”

Characterization of meso- and macroporous ceramic membranes in terms of flux measurement: A moment-based analysis

“…Only pores active to permeation are detected [14][15][16][17] It requires knowledge of contact angles Liquid and gas flux measurement Liquid and gas permeabilities are monitored as a function of the pressure drop across the membrane…”