Eigenschaften von gepfropften Polymeren unter veränderlichen Lösungsmittelbedingungen und ihre Wechselwirkung mit Nanoteilchen

• Applicant: Professor Dr. Jens-Uwe Sommer
• Subject Area: Experimental and Theoretical Physics of Polymers
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 204294490

We study the properties of grafted polymer chains (polymer brushes) and their interactions with nanoparticles under the influence of strongly varying solvent quality. We use the bond fluctuation model with explicit solvent. This ensures a high mobility within the polymer phase even under very poor solvent conditions. High efficiency of the code is achieved by porting to graphical processor units. First, we we study the properties of grafted polymers without nanoparticles in a wide range of solvent conditions. Of particular interest are mechanisms of lateral structure formation under poor solvent quality. Of interest are both grafting densities below the overlap threshold (micellation) and densities far above the overlap threshold. Our method allows for system sizes large enough to quantitatively characterize structure formation and to test existing theoretical models. In a second part of the project we study the adsorption and uptake of nanoparticles in polymer brushes under variation of solvent quality. In particular, during reduction of solvent quality, we consider possible changes of localization of nanoparticles and the impact of lateral structure formation on the organization of nanoparticles on the brush surface. Based on our simulation results we develop state/phase diagrams and theoretical models (Mean-Field, Scaling) to predict the properties of polymer-nanoparticle-systems under strong variation of solvent quality. Our results may find applications in surface technology and for the development of biologically active substrates.

• DFG Programme: Research Grants