An Investigation into the Formation Pathway of Peptoid Supramolecular Structures

Abstract

Functions of nanomaterials assembled from sequence-defined macromolecules are highly determined by their molecular packings and self-assembled morphologies. Peptoids, N-substituted glycines, are one type of well-developed sequence-defined synthetic polymers that mimic peptides and proteins for function. Due to the lack of hydrogen bond donors, peptoids exhibit unique features for self-assembly into well-shaped structures including nanotubes, nanosheets and nano-helices. While tremendous efforts are made in the design of peptoid sequences for hierarchical assembly, the formation pathway and assembly mechanisms of numerous supramolecular structures of peptoid assemblies remain unexplored. In this thesis, we have performed a systematic study of the peptoid self-assembly process by varying factors such as solvent type, solvent ratio, temperature and electrostatic interaction. We have successfully generated the three typical morphologies from a single peptoid sequence by manipulating self-assembly conditions. These findings provide evidence for the construction of a peptoid self-assembly energy landscape and support the possibility of achieving precise control of a formation pathway.