Gels, Polymers, and "active" Colloids

Group leader: Patrick Kreissl Members: Christian Holm, David Beyer, Mariano Brito, Patrick Kreissl, Rudolf Weeber, Slavko Kondrat

Schedule

The meeting takes place every three weeks on Tuesday at 10:30, if not indicated differently.

WS 2018

• 12.12.2017 We discussed possible Bachelor topics:
  • ampholytic salt between colloids (so big that they are modeled as plate capacitors), Podgornik Project -Jonas
  • flow between charge regulated walls with Comsol (not Reaction Ensemble due to Dynamics being destroyed by MC) -Floh, Patrick, Jonas
  • Neural Net Topic - Anand
  • Bacteria in Porous Geometries, Espresso vs. Walberla - Michael
  • Gel with free magnetic particles, magneto-elastic behavior (Alignment of magnetic particles with attractive Lennard Jones interaction?)- Rudolf, Patrick
  • Porous nanogel in conical glass nanopore - Kai
  • ICC improvements Konrad, Floh
• 24.10.2017 Jonas: Poisson-Boltzmann Cell Model under Tension, correct treatment and results. Discussed why results for (single chain) PB Cell Model differ from Tobis MD results for gels (see the presentation "/home/jlandsgesell/phd/presentations/Poisson\ Boltzmann\ Cell\ Model\ Progress\ Report\ 24.10.2017.odp"). Agreed on investigating single chain properties further. The optimal cell model where pressures equal on the top and the side was ruled out to be a bad model since it would like swell to infinity in radial direction.

SS 2017

• 9.05.2017 Kai: Autocorrelation time of confined polymers, Patrick: made COMSOL implementation of Cell Model for taking finite differences (p=-del F(N,V,T)/del V), Jonas: discussed working together with Peters on weak polyelectrolytes in poor solvents and working with Peter on bulk vs. local pH values, David: mobility of weak stars, Michael: Problems with reactive boundary condition and momentum conservation
• 18.04.2017
  • F. Weik: B-spline fit to polymer conformations and error calculation for Eigenvalue problems (both related to Evangelos' project of DNA translocation).
  • P. Kreissl: Writing proposal for magnetic gels project together with R. Weeber.
  • K. Szuttor: Writing response to paper review (almost done).
  • M. Kuron: Bachelor student's thesis deadline is soon. Moving boundary EK debugging progresses, but not finished. Literature resesearch on visco-elastic LB: -Malas-Pinas model may not be the best choice acc. to Joost et al. -Flo: talk to U. Schiller

WS 2016

• 28.03.2017 We discussed results from the DPG meeting (e.g. Microgels from the group of Richtering, Aachen, https://sharepoint.ecampus.rwth-aachen.de/vo/microgels/aussen/SitePages/Publications.aspx), strategies for moving L-shaped swimmers and simulating weak hydrogels in an external electric field.
• 28.02.2017 Jonas: We discussed the Poisson Boltzmann Cell Model, the free energy contributions which are necessary to determine the swelling equilibrium and first results of the COMSOL model.
• 7.02.2017 Kai: We discussed the relaxation time behaviour of the first Rouse mode for uncharged polymers tethered to a wall in the presence of hydrodynamic interactions. There seems to be a crossover for the relaxation times, depending on the channel height and polymer length.
• 18.01.2017 Julia presented the Computation of the 'Morphological Computation' for L shaped active swimmers. Nicolai presented results not included in his master thesis: susceptibilities/ relaxation times/ magnetization for isotropic/ uniaxial magnetic gels regarding the influence of Hydrodynamics (LB vs. Langevin thermostat). Idea of simulating ferro fluids due to more experimental data.
• 22.11.2016 Presentation of the Desalination Paper of Tobias, Progress report of Patrick (active colloid in viscous medium modeled by entangled protein solution)
• 13.1.2016 Patrick: Discussed how to test in simulations the magnetization model of anisotropic particles in an external magnetic field in an elastic medium. Further discussed why an active colloid in a viscoelastic medium could have an increased rotational diffusion. Kai: presented his paper on polymer stretching.

SS 2016

• Tue, 27.09.2016 Progess reports by Julia (active L-shaped microswimmers) and Sebastian (sheared gels with Lees-Edwards boundary conditions)

WS 2015/16

• Wed, 03.02.2016 External guest Daniel Häufle: L-shaped microswimmers
• Wed, 13.01.2016 Progress reports
• Wed, 25.11.2015 Progress report from the active Matter fraction

SS 2014

• Wed, 3.9.2014
• Wed, 13.8.2014 Coarse graining out the connecting polymers in magnetic gels (RW)
• Wed, 23.7.2014
• Wed, 2.7.2014 Observables feature in ESPResSo by Stefan, some remarks on TRAVIS analysis tool for MD trajectories by Konrad
• Wed, 11.6.2014
• Wed, 21.5.2014 Progress reports
• Wed, 30.4.2014 The reaction ensemble, integrating chemical reactions into computer simulations (TR)
• Wed, 9.4.2014 Starting the semester with status/progress reports

WS 2013/2014

• Wed, 12.02.2014: Extraordinary Time: 15:30, Topic will be reports on progress and problems
• Wed, 15.01.2013: Cell under tension model for hydrogels (TR)
• Wed, 04.12.2013: fitting elastic constants in magnetic gels (RW) and as backup: Poisson-Boltzmann Cell under tension model for hydrogels (TR)
• Wed, 20.11.2013: Continuation of the blob picture for polymers under confinement, maybe talk on fitting elastic constants
• Wed, 06.11.2013: Talks on Blobology: Pincus blobs, Polymer blobs under confinement, electrostatic blobs
• Wed, 23.10.2013: Progress Report
• Wed, 2.10.2013: Initial meeting

Additional Material

Overview over active swimmers by Joost active swimmers (6.83 MB)

Some remarks on literature research by Joost literature research (1.9 MB)

Overview for the reaction ensemble method plus example implementation: reaction ensemble (255 KB)