Polymer cyclization for the emergence of hierarchical nanostructures

Chaojian Chen,Colette J Whitfield,Katharina Landfester,Manjesh Kumar Singh,Manfred Wagner,Sean Harvey,Zhixuan Zhou,George Fytas,Ingo Lieberwirth,Katrin Wunderlich,Tanja Weil,Kurt Kremer,Debashish Mukherji,David Y W Ng

doi:10.1038/s41467-021-24222-5

Abstract

The creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.

Highlights

The creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics
To demonstrate that synthetic polymers can be folded into specific forms for constructing higher ordered structures, polymers of hydroxyethyl methacrylate (HEMA) (PHEMA) were folded into the cyclic topology, which is a well-established approach to fold polymers[21]
Three linear PHEMA samples (l-PHEMAn-Br, where n represents the number of repeating units) of different lengths were synthesized via atom transfer radical polymerization (ATRP) using propargyl 2bromoisobutyrate as the initiator (Fig. 1a)

Summary

Introduction

The creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. We focus on the emergence of structural complexity by folding of polymer chains forming unique cyclic structures capable of assembly into wormlike hierarchical structures. To investigate if a single f-PHEMA15 (Supplementary Fig. 24) retains its well-defined cyclic structure in pure water, we performed an all-atom molecular dynamics simulation.

Results

Conclusion