DFG Priority Program SPP 1164
Nano- & Microfluidics:
Bridging the Gap between
Molecular Motion and Continuum Flow
Capillary Rise and Flow of Complex Liquids in Nanopores
| Project Leader: | Dr. Patrick Huber Universität des Saarlandes Fachrichtung 7.3 – Technische Physik Saarbrücken |
Summary
We propose to study the flow of complex liquids
in monolithic, porous silica glasses and porous silicon (mean pore diameter d=10nm)
as a function of the size and shape of the building blocks of the liquids and
the applied shear rates. In particular, we would like to compare flow rate
measurements taken in a membrane flow apparatus with measurements on the
spontaneous imbibition, that is the capillary rise in the pores driven by capillary
forces. Whereas the flow apparatus measurements will allow us to determine the
viscosities of the nanoconfined liquids, the filling process of the capillary
rise crucially depends not only on the viscous drag but also on the capillary
pressure acting in the nanopores. In order to vary the complexity of the
liquids we suggest to measure liquids built out of chain-like (n-alkanes),
rod-like and disc-like (liquid crystals) molecules – all of them with molecular
sizes on the order of the diameter of the nanopores. The experimental study
will shed light on the question to what extend continuum-like, macroscopic
fluid behaviour is valid down to nano-scopic length scales.