New Micro- and Nano-Scale Imaging Methods for Fluid and Gas Transport through Porous Media

H. Reingruber1, P. Pölt2 and B. Holst3

1Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, A-8010 Graz, Austria

2Graz University of Technology, Institute for Electron Microscopy, Steyrergasse 17, A-8010 Graz, Austria

3University of Bergen, Department of Physics and Technology, Allegt. 55, N-5007, Bergen, Norway, Email: bodil@cantab.net

ABSTRACT

In this paper two new methods for investigating the transport properties of gas and liquids through porous materials on the micro/nano scale are presented. No other methods for carrying out such measurements are presently available. Firstly we show first results applying a focused beam of neutral helium atoms as a new microscopy tool and using this focused beam to measure the gas transport through porous membranes. Secondly we show first results using an environmental scanning electron microscope to measure the wetting properties of porous membranes; A water reservoir is created by cooling a small basin on which the porous membrane sample is placed. Eventually, when enough water has condensed to wet the sample, the liquid front can be imaged by the electron beam at the sample surface as it emerges.

Keywords micro/nano scale imaging, transmissivity, porous media, transport properties