Controlling chain entanglements in bottlebrush polymers for biomedical applications

Brush architecture disentangles network strands, increases osmotic pressure, and weakens the elastic force towards enhanced swellability. However, steric repulsion between side chains also leads to backbone strand extension resulting in increased non-linear stress response, which counteracts swelling. This tug-of-war governs the resulting mechanical properties of swollen gels and remains poorly understood. It is clear that brush side chains play multiple roles that may either promote or suppress gel swelling. In the present experiment, we will explore properties of bottlebrush-based elastomers upon exposure to various solvents. By performing in-situ USAXS/WAXS couples with fast mechanical stretching and heating of swollen samples we are planning to uncover the architecture-mediated interplay between gel assembly, swelling and mechanics. This knowledge will enable fabricating soft materials with orthogonal control of chemical composition, mechanical properties, and functionality.