English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Polymers are known to wet nanopores with high surface energy through anatomically thin precursor film followed by slower capillary filling. We presenthere light interference spectroscopy using a nanoporous membrane-based chipthat allows us to observe the dynamics of these phenomena in situ withsub-nanometer spatial and milli- to microsecond temporal resolution. The deviceconsists of a mesoporous silicon film (average pore size 6 nm) with anintegrated photonic crystal, which permits to simultaneously measure the phaseshift of the thin-film interference and the resonance of the photonic crystalupon imbibition. For a styrene dimer, we find a flat fluid front without aprecursor film, while the pentamer forms an expanding molecular thin filmmoving in front of the menisci of the capillary filling. These differentbehaviors are attributed to a significantly faster pore-surface diffusioncompared to the imbibition dynamics for the pentamer and vice versa for thedimer. In addition, both oligomers exhibit anomalously slow imbibitiondynamics, which could be explained by apparent viscosities of six and eleventimes the bulk value, respectively. However, a more consistent description ofthe dynamics is achieved by a constriction model that emphasizes the increasingimportance of local undulations in the pore radius with the molecular size andincludes a sub-nanometer hydrodynamic dead, immobile zone at the pore wall, butotherwise uses bulk fluid parameters. Overall, our study illustrates thatinterferometric, opto-fluidic experiments with nanoporous media allow for aremarkably detailed exploration of the nano-rheology of polymeric liquids.

Polymeric Liquids in Nanoporous Photonic Structures: From Precursor Film Spreading to Imbibition Dynamics at the Nanoscale