Simulations of weak polyelectrolytes: interplay of acid-base equilibria, ion correlations and polymer topology

• Applicant: Professor Dr. Christian Holm, since 3/2015
• Subject Area: Experimental and Theoretical Physics of Polymers
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 249041160

This project focuses on simulations of weak (annealed) polyelectrolytes, i.e. polymers which act as weak bases or acids in solution, for example polyacrylic acid. Such polymers are commonly used as super absorbers, for example in baby diapers. However, little is known about the interplay of topology, salts and acid-base-equilibria, that determines the structure of the polyelectrolytes. We will use an optimized method to simulate the acid-base equilibria in polyelectrolyte solutions including explicit ions. As topologies, we will consider star polymers as well as true networks, and besides the charges dynamically generated by dissociation we will also take into account ions from mono- and multivalent salts. By that, we will develop theoretical models for the structure of weak polyelectrolytes under realistic conditions, and by that contribute to our understanding of their unique properties.The project brings together research teams with complementary background in chemistry, physics andcomputer simulations, who have overlapping research interests in polyelectrolyte solutions. The employed simulation technique will be part of the open source ESPResSo simulation software to make it available to other researchers.This project is planned as a collaboration between the University of Stuttgart and the Charles University in Prague. A corresponding application for funding of the Czech partner has already been submitted to the Czech grant agency GACR.

• DFG Programme: Research Grants
• International Connection: Czech Republic
• Partner Organisation: Czech Science Foundation
• Participating Persons: Professor Dr. Peter Kosovan; Dr. Filip Uhlik
• Ehemaliger Antragsteller: Professor Dr. Axel Arnold, until 2/2015