Imaging the conformation and dynamics single polymers in bulk environments

The behavior of single chains is integral to the foundation of polymer science. For example, many theories explaining fundamental behavior originate from how a single polymer interacts and responds to its environment, often made of other polymer chains. However, in this situation it is particularly difficult to visualize the behavior of single polymers, particularly because of the required nanoscale resolutions, and the lack of contrast between otherwise identical polymer chains. We use single-molecule super-resolution optical microscopy to directly image the conformation and dynamics of polymers in real time and in their native environment. In one example, we acquire images of fluorescently-labeled bottlebrush polymers blended with an unlabeled linear polymer melt. By fitting these images to a wormlike chain model, we are able to accurately and directly measure the persistence length of the backbone for the first time. Subsequent work shows how these conformations are affected by the sample environment, by changing the surrounding matrix from linear to bottlebrush polymers for example.