title: Depinning and dynamics of imbibition fronts in paper under increasing ambient humidity.
abstract: We study the effects of ambient air humidity on the dynamics of imbibition in a paper. We observed that a quick increase of ambient air humidity leads to depinning and non-Washburn motion of wetting fronts. Specifically, we found that after depinning the wetting front moves with decreasing velocity v[proportionality](h(p)/h(D))(γ), where h(D) is the front elevation with respect to its pinned position at lower humidity h(p), while γ=/~1/3. The spatiotemporal maps of depinned front activity are established. The front motion is controlled by the dynamics of local avalanches directed at 30° to the balk flow direction. Although the roughness of the pinned wetting front is self-affine and the avalanche size distribution displays a power-law asymptotic, the roughness of the moving front becomes multiaffine a few minutes after depinning.
authors: Grupo Mecánica Fractal, Instituto Politécnico Nacional, México D.F., Mexico 07738.
authors: Alexander S
authors: AS
authors: Balankin
authors: H
authors: H
authors: Zapata López
authors: E
authors: E
authors: Pineda León
authors: D
authors: D
authors: Morales Matamoros
authors: L
authors: L
authors: Morales Ruiz
authors: Dan
authors: D
authors: Silva López
authors: M A
authors: MA
authors: Rodríguez
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D006813:Humidity; D015233:Models, Statistical; D010209:Paper; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D014867:Water