title: Imbibition Triggered by Capillary Condensation in Nanopores.
abstract: We study the spatiotemporal dynamics of water uptake by capillary condensation from unsaturated vapor in mesoporous silicon layers (pore radius rp≃ 2 nm), taking advantage of the local changes in optical reflectance as a function of water saturation. Our experiments elucidate two qualitatively different regimes as a function of the imposed external vapor pressure: at low vapor pressures, equilibration occurs via a diffusion-like process; at high vapor pressures, an imbibition-like wetting front results in fast equilibration toward a fully saturated sample. We show that the imbibition dynamics can be described by a modified Lucas-Washburn equation that takes into account the liquid stresses implied by Kelvin equation.
authors.affiliation: Robert Frederick Smith School of Chemical and Biomolecular Engineering and ‡Kavli Institute at Cornell for Nanoscale Science, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Olivier
authors.identifier: 0000-0002-8876-6072
authors.initials: O
authors.lastname: Vincent
authors.affiliation: Robert Frederick Smith School of Chemical and Biomolecular Engineering and ‡Kavli Institute at Cornell for Nanoscale Science, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Bastien
authors.initials: B
authors.lastname: Marguet
authors.affiliation: Robert Frederick Smith School of Chemical and Biomolecular Engineering and ‡Kavli Institute at Cornell for Nanoscale Science, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Abraham D
authors.initials: AD
authors.lastname: Stroock