Capillary Condensation in a Fractal Porous Medium
Small-angle x-ray and neutron scattering are used to characterize the surface roughness and porosity of a natural rock which are described over three decades in length scales and over nine decades in scattered intensities by a surface fractal dimension D=2.68{+-}0.03 . When this porous medium is exposed to a vapor of a contrast-matched water, neutron scattering reveals that surface roughness disappears at small scales, where a Porod behavior typical of smooth interfaces is observed instead. Water-sorption measurements confirm that such interface smoothing is due predominantly to the water condensing in the most strongly curved asperities rather than covering the surface with a wetting film of uniform thickness.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40203667
- Journal Information:
- Physical Review Letters, Vol. 86, Issue 23; Other Information: DOI: 10.1103/PhysRevLett.86.5313; Othernumber: PRLTAO000086000023005313000001; 038123PRL; PBD: 4 Jun 2001; ISSN 0031-9007
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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