Topological Constraints Do Matter: Playing with Entanglements

The fact that polymer chains cannot cross through each other has many consequences, which range from functions in cell biology to properties of polymer commodities.

These constraints typically are seen as a problem that complicate the properties and that pose huge problems in understanding and proper analysis. For standard long chain polymer melts chain entanglements are known to dominate the rheological properties and lead to the generally accepted and well established reptation/tube model. In contrast, the dense solution of long DNA chains in the cell nucleus avoids entanglements, as demonstrated by the co called chromosome territories. However, beyond analysing their effects and understanding the very nature of entanglements, one also can take the approach to use them to manipulate and structure materials, either by avoiding or explicitly using them.

The talk will give a few such examples ranging from melts of non-entangled to very long, highly entangled polymer systems. By appropriately mapping chemical chain lengths onto idealized bead spring models one can (semi-) quantitatively compare simulation and experiment and predict new materials.

[1] J. D. Halverson, J. Smrek, K. Kremer, and A. Y. Grosberg, Rep. on Prog. in Phys., 77 (2014).
[2] H. P. Hsu, M. K. Singh, Y. Cang, H. Thérien-Aubin, M. Mezger, R. Berger, I. Leiberwirth, G. Fytas, and K Kremer, Adv. Sci. 10, 2207472 (2023).
[4] M. K. Singh, M. Hu, Y. Cang, H. P. Hsu, H. Thérien -Aubin, K. Koynov, G. Fytas, K. Landfester, and K. Kremer, Macromolecules 53, 7312 (2020).