title: Complex Filling Dynamics in Mesoporous Thin Films.
abstract: The fluid-front dynamics resulting from the coexisting infiltration and evaporation phenomena in nanofluidic systems has been investigated. More precisely, water infiltration in both titania and silica mesoporous films was studied through a simple experiment: a sessile drop was deposited over the film and the advancement of the fluid front into the porous structure was optically followed and recorded in time. In the case of titania mesoporous films, capillary infiltration was arrested at a given distance, and a steady annular region of the wetted material was formed. A simple model that combines Lucas-Washburn infiltration and surface evaporation was derived, which appropriately describes the observed filling dynamics and the annulus width in dissimilar mesoporous morphologies. In the case of wormlike mesoporous morphologies, a remarkable phenomenon was found: instead of reaching a steady infiltration-evaporation balance, the fluid front exhibits an oscillating behavior. This complex filling dynamics opens interesting possibilities to study the unusual nanofluidic phenomena and to discover novel applications.
authors.affiliation: Departamento de Micro y Nanotecnología, Comisión Nacional de Energía Atómica , Avenida General Paz 1499, San Martín, B1650 Buenos Aires, Argentina.
authors.forename: Magalí
authors.initials: M
authors.lastname: Mercuri
authors.affiliation: Departamento de Micro y Nanotecnología, Comisión Nacional de Energía Atómica , Avenida General Paz 1499, San Martín, B1650 Buenos Aires, Argentina.
authors.forename: Karina
authors.initials: K
authors.lastname: Pierpauli
authors.affiliation: Departamento de Micro y Nanotecnología, Comisión Nacional de Energía Atómica , Avenida General Paz 1499, San Martín, B1650 Buenos Aires, Argentina.
authors.forename: Martín G
authors.initials: MG
authors.lastname: Bellino
authors.affiliation: INTEC (Universidad Nacional del Litoral-CONICET) Predio CCT CONICET Santa Fe , RN 168, S3000 Santa Fe, Argentina.
authors.forename: Claudio L A
authors.identifier: 0000-0002-1321-6738
authors.initials: CL
authors.lastname: Berli