Simulations to Probe Structure and Mobilities of Poly electrolyte Multilayer Systems of variable Size

• Applicant: Professor Dr. Christian Holm
• Subject Area: Experimental and Theoretical Physics of Polymers
• Term: from 2008 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 67499234

In the last funding period we investigated extensively the inner structure and dynamics of a small number of polyelectrolyte multilayers (PEMs) by means of atomistic and coarse-grained simulations. Our obtained results allowed us to understand some important features of PEMs, regarding the electrostatic interactions and water diffusion in particular, but also pointed out the need for a more refined coarsegrained model. Our first aim in the next funding period is to develope and test such a coarse-grained model, employing as a reference both experimental data and results from atomistic simulations which proved to be able to reach quantitative agreement with experiments. As system we will realize the first model of an adsorbed PE bilayer at atomistic detail, from which we plan to extract valuable information about the microscopic structure of the PEs and of the solvent in the layers. With the improved CG model we plan to investigate structural and dynamical properties of the PEMs in the interphase, this time at the quantitative level, such as their stability in dependence of several parameters (substrate hydrophobicity/ hydrophilicity), the distribution of water voids, the mobilities of chains and tracer particles within the layers parallel and perpendicular to the surface, and the surface roughness. We also want to simulate PE pulling experiments parallel and perpendicular to the layer.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1369: Polymer Solid Contacts: Interfaces and Interphases