Berlin 2012 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 23: Poster: Polymer Dynamics
CPP 23.14: Poster
Wednesday, March 28, 2012, 11:00–13:00, Poster A
Filling process in cylindrical nanopores — •Manuela Lukas and Bernd Stühn — Experimentelle Physik kondensierter Materie, TU Darmstadt, Germany
The aim of this work is to investigate the filling flow behavior of polymers in nanopores using time resolved Small-Angle X-ray Scattering (SAXS). The nanoporous samples consist of a polycarbonate foil with thickness 30 µ m, irridated with swift heavy ions (ion tracked polycarbonate: ITPC), treated with UV light and etched in NaOH solution. Varying the etching time the cylinder radii can be controlled. In ITPC nanopores are aligned strictly parallel. For filling experiments polydimethylsiloxane (PDMS) with three different molecular weights, (M=28,000 g/mol, M=63,000 g/mol, M=139,000 g/mol), is used. PDMS was chosen because its electron density with ρ = 319 e/nm3 is different to the electron density of the matrix material polycarbonat with ρ = 380 e/nm3 showing a good contrast for SAXS. The filling process is shown by the steady decrease in scattering intensity with time. It turns out that the intensity variation with time follows the Lucas-Washburn equation. The √t -dependency of the filling height is reproduced well throughout the whole filling process. However a quantitative analysis of the full scattering profiles reveals a remarkable deviation from the classical filling behaviour [M. Engel, B. Stühn. J. Chem. Phys. 132, 224502, 2010]. Furthermore the data suggest the forming of a precursorfilm.