Molecular Design of Novel Polymer Materials Based on Bottlebrush Macromolecules

• Applicant: Professor Dr. Jaroslaw Paturej
• Subject Area: Experimental and Theoretical Physics of Polymers
• Term: from 2017 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 337847083

• Final Report Year: 2021

Final Report Abstract

The modification of polymer properties due to change in macromolecular architecture is of fundamental interests for polymer physics. The research contained in this project addressed this issue on the example of branched architecture of bottlebrush polymers. Polymer bottlebrushes provide intriguing features being relevant both in nature and in synthetic systems. While their presence in the articular cartilage optimizes synovial joint lubrication, bottlebrushes offer pathways for fascinating applications, such as within super-soft elastomers or for drug delivery. However, the theoretical understanding of these branched polymers was lacking completeness. This is primarily due to the complicated interplay of many length scales which is hard to incorporate in the analytic theory. In this project an analytical model was developed that demonstrates how structural and micromechanical properties of bottlebrushes depend on the concentration, ranging from dilute solutions to highly concentrated melts. The validity of this model is supported by data from extensive molecular dynamics simulations. It was demonstrated that the hierarchical structure of bottlebrushes dictates a sequence of conformational changes as the solution concentration increases. The effect is mediated by screening of excluded volume interactions at subsequent structural parts of the bottlebrushes. These findings provide important insights that should enable improved customization of novel materials based on the architectural design of polymer bottlebrushes.

Publications

• (2017). Hierarchical excluded volume screening in solutions of bottlebrush polymers. Soft matter, 13(45), 8534-8541
  J. Paturej and T. Kreer
  (See online at https://doi.org/10.1039/c7sm01968h)
• (2019). Universal equation of state for flexible polymers beyond the semidilute regime. Physical Review Letters, 122(8), 087801
  J. Paturej, J.-U. Sommer and T. Kreer
  (See online at https://doi.org/10.1103/physrevlett.122.087801)