Peter George Frank, University of New Hampshire, Durham


Well-defined linear polymers precisely folded into nanostructures, capable of performing complex functions both individually and collaboratively, are abundant in nature. This has inspired numerous research groups to replicate this approach synthetically. The effort has been bolstered by recent advances in controlled polymerizations that facilitate a more precise synthesis of polymer chains with varying backbones and placement of functional groups albeit not as precise as nature. Based on the discrete folding of these polymer chains, single-chain nanotechnology is a facile route to functional nano-objects that may be applied to areas spanning nanomedicine, sensing, catalysis, electro-active materials, and hierarchical self-assemblies. This dissertation reports an investigation on the discrete folding of synthetic polymers with anthracene.

Chapter 1, General Introduction and Motivation, is an introductory chapter that provides the background and divulges the importance, as well as the implications of single-chain nanoparticles (SCNPs) in synthesis, characterization and a host of applications. In Chapter 2 the development of a photo-driven single-chain nanotechnology is described. The anthracene decorated polymer chains are investigated via photo-driven folding under mild and ambient conditions to yield nanoparticles. Additionally, sequential folding can be achieved by incremental exposure to ultraviolet light that allows the precise targeting of nanoparticle size while maintaining uniformity from parent polymer to the particle. The developed single-chain nanotechnology has three independent sites that can undergo chemical modifications to tailor particle function as desired.

In chapter 3 the effects of parent polymer molecular weight and stiffness on the formation of photo-folded SCNPs are studied. Furthermore, the morphological aspects of general SCNPs are described in the context of advanced characterizations with microscopy, and small angle scattering. Finally, in chapter 4 the formation of SCNPs by an alternate photodimerization moiety, coumarin is explored. The synthetic strategy is discussed, but SCNP fabrication with these materials is beyond the scope of this dissertation.