PNNL

Abstract

Hierarchical self-assembly represents a powerful strategy for the fabrication of functional materials at various length scales. A notable example is the assembly of proteins in living systems, where the protein sequence encodes information about the resulting hierarchical biomaterials. Taking inspiration from these protein assemblies, researchers have explored the use of sequence-defined synthetic polymers as peptidomimetics for the hierarchical assembly of functional materials capable of storing information within polymer chains. However, achieving protein-like hierarchical synthetic materials remains a challenging task that requires a profound understanding of molecular interactions and precise control over the assembly process of polymer building blocks. In this study, we present a molecular-level understanding of the hierarchical assembly of sequence-defined peptoids into multidimensional functional materials, including twisted nanotube bundles serving as highly efficient artificial light harvesting systems. By employing synchrotron-based powder X-ray diffraction and analyzing single crystal structures of model compounds, we elucidated the molecular packing and mechanisms underlying the assembly of peptoids into multidimensional nanostructures. Our findings demonstrate that incorporating aromatic functional groups, such as tetraphenyl ethylene (TPE), at the termini of assembling peptoid sequences promotes the formation of twisted bundles of nanotubes and nanosheets, thus enabling the creation of a highly efficient artificial light harvesting system. This research exemplifies the potential of leveraging sequence-defined synthetic polymers to translate microscopic molecular structures into macroscopic assemblies. It holds promise for the development of functional materials with precisely controlled hierarchical structures and designed functions.