Biopolymer Nanoscale Assemblies as Building Blocks for New Materials: A Review

Abstract Biopolymers, a class of fascinating polymers from biomass provide sustainability, biodegradability, availability, biocompatibility, and unique properties. A ubiquitous feature of biopolymers is their hierarchical structure, with the presence of well‐organized structures from the nanoscale to macroscopic dimensions. This structural organization endows biopolymers with toughness, defect resistance, and bucking adaptability. To retain these inherent structural features, nano‐structural assemblies isolated from biomass have been applied as building blocks to construct new biopolymer‐based materials. This top‐down processing strategy is distinct from the more traditional molecular‐level bottom‐up design and assembly approach for new materials. In this review, the hierarchical structures of several representative biopolymers (cellulose, chitin, silk, collagen) are introduced with a focus on these nanoscale building blocks, as well as highlighting the similarities and differences in the respective chemistries and structures. Recent progress in production strategies of these natural building blocks are summarized, covering methods and treatments used for isolations. Finally, approaches and emerging applications of biopolymer‐based materials using these natural nano‐ and meso‐scale building blocks are demonstrated in areas of biomedicine, electronics, environmental, packaging, sensing, foods, and cosmetics.