TY  - JOUR
AU  - Cencha, Luisa G.
AU  - Dittrich, Guido
AU  - Huber, Patrick
AU  - Berli, Claudio L. A.
AU  - Urteaga, Raul
TI  - Precursor Film Spreading during Liquid Imbibition in Nanoporous Photonic Crystals
JO  - Physical review letters
VL  - 125
IS  - 23
SN  - 1079-7114
CY  - College Park, Md.
PB  - APS
M1  - PUBDB-2021-01452
SP  - 234502
PY  - 2020
AB  - When a macroscopic droplet spreads, a thin precursor film of liquid moves ahead of the advancing liquid-solid-vapor contact line. Whereas this phenomenon has been explored extensively for planar solid substrates, its presence in nanostructured geometries has barely been studied so far, despite its importance for many natural and technological fluid transport processes. Here we use porous photonic crystals in silicon to resolve by light interferometry capillarity-driven spreading of liquid fronts in pores of few nanometers in radius. Upon spatiotemporal rescaling the fluid profiles collapse on master curves indicating that all imbibition fronts follow a square-root-of-time broadening dynamics. For the simple liquid (glycerol) a sharp front with a widening typical of Lucas-Washburn capillary-rise dynamics in a medium with pore-size distribution occurs. By contrast, for a polymer (PDMS) a precursor film moving ahead of the main menisci entirely alters the nature of the nanoscale transport, in agreement with predictions of computer simulations.
LB  - PUB:(DE-HGF)16
C6  - pmid:33337190
UR  - <Go to ISI:>//WOS:000595043900011
DO  - DOI:10.1103/PhysRevLett.125.234502
UR  - https://bib-pubdb1.desy.de/record/456316
ER  -