The preparation of polymer brushes by surface-initiated atom transfer radical polymerization (SI-ATRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces. Taking advantage of the assets of SI-ATRP, we study the fundamental research questions with regard to the sensitivity of chemical bonds towards mechanical forces and synthesize functional polymer brush films that can serve as bioadhesives or which possess noncentrosymmetric materials properties.<br/>The first part of this research demonstrates the use of SI-ATRP to prepare PtBMA brush films that are used as a model system to better understand the effect of weak mechanical forces on the hydrolysis of ester/amide and siloxane bond. The question is that decoupling the effect of swelling and the water contribution to the rate of the hydrolysis is not possible. Using the hydrophobic brushes here, it has been possible for the first time to unambiguously decouple swelling and bond hydrolysis. Comparison of reaction rate constants measured in solvents of different quality suggested that degrafting correlates with brush swelling, demonstrating the mechanochemical nature of this process.<br/>In the second part of this research, we focus on the development of thin polymer films that allow to control adhesion between synthetic materials and tissue. PHEMA brushes have been prepared that can be transformed, on-demand using UV light from a non-fouling surface coating into a bioadhesive interface. Two synthetic approaches towards such films are discussed.<br/>The third part of the research attempts to understand the pyroelectric behavior of polyelectrolyte (PE) brushes prepared via SI-ATRP. A clear current change was detected when the substrate modified with PE brushes was connected to an open circuit and subjected to an alternating sequence of temperature changes. We hypothesize that the pyroelectric current comes from the vibration of the permanent dipole moment in the materials. This permanent dipole moment is believed to be the consequence of a non-neutral net charge within the polymer brush film.

Functional and responsive polymer brushes via surface-initiated atom transfer radical polymerization

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.