USTC: Discontinuous Bouligand Structure for Strong and Damage-Tolerant Nanocomposites

Bouligand structure is widely present in biological materials such as fish scale, bone and lobster underbelly, which endows them with superior mechanical performance to triumph in the brutal competitions for survival. The structure is composed of unidirectional nanofiber lamellae that are spirally stacked, which is a typical fiber-reinforced structure, providing plenty of inspirations for the development of engineering fiber-reinforced composites. Although considerable progress has been made in biomimetic Bouligand structural materials, transformation of natural Bouligand structure and its connotations into synthetic material systems still remains challenging.

In a recent study published in Matter, a research team led by Prof. YU Shuhong, from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences, proposed a concept of discontinuous Bouligand structure and developed a programmable strategy to orderly assemble discrete nanofibers via brushing, ultimately achieving the construction of biomimetic discontinuous Bouligand structure.

Based on the developed programmable assembly strategy, Yu and co-workers spirally assembled the eco-friendly xonotlite nanofibers within the sodium alginate matrix, and successfully prepared biomimetic discontinuous Bouligand structural nanocomposite.

The as-prepared biomimetic nanocomposite exhibited excellent mechanical properties with high tensile strength, high toughness and long fatigue durability, outperforming many natural Bouligand structural materials, as well as engineering fiber-reinforced composites.

Apart from conventional thin films, researchers could construct thick bulk discontinuous Bouligand structural materials via their previously reported lamination and interfacial welding technique. Due to the biocompatibility of the components and the diversity of material sizes, the prepared nanocomposites had broad application prospects, such as bone repair materials with high damage tolerance. More importantly, the proposed discontinuous Bouligand structural design and programmable assembly strategy could be used for developing new-style nanofibrous composites and improving traditional fiber-reinforced plastic composite materials.