logo-fast uniblau klein.png

IRTG / Soft Matter Science
Freiburger Materialforschungszentrum
Stefan-Meier-Str. 21
79104 Freiburg, Germany


|    Flyer   |   Poster   |

You are here: Home Events Dr. Hans Riegler "Physics of Spin Casting Dilute Solutions"

Dr. Hans Riegler "Physics of Spin Casting Dilute Solutions"

— filed under:

MPI für Kolloid- und Grenzflächenforschung, Potsdam

  • Seminar
When Nov 14, 2013
from 02:15 PM to 03:00 PM
Where Seminarraum B, FMF, Stefan-Meier-Str. 21, Freiburg, Thursday
Add event to calendar vCal

We analyze spin casting assuming a mixture of a non-volatile solute and a volatile solvent. Our focus is on the evolution of the internal local solute composition during film thinning. We assume that the volatile component dominates the hydrodynamic-evaporative film thinning (with constant evaporation rates and spin-off coefficients).  The internal spatio-temporal compositional evolution is analyzed with a diffusive-advective approach. The analysis reveals a characteristic, experimentally accessible Sherwood Number, Sh, as fundamental process parameter. This Sh identifies when and where the analysis is relevant and whether solute diffusion (Sh<1) or solvent evaporation (Sh>1) dominates the spatial compositional evolution. Power laws link the process duration, final solute coverage and evolution of the internal film composition to the spin casting control parameters and the properties of the initial solution.  The quantitative validity of the analysis can be verified experimentally and provides palpable physical insight into the influence of the different process parameters. It is valid for the deposition of structured (sub)monolayers (“evaporation-induced self-assembly'') but also relevant for the deposition of thicker (polymer) films. In addition to the theoretical analysis we also present experimental results including real time high spatial resolution imaging of the film thinning respectively solute deposition with millisecond time resolution. 

Personal tools