Xiong Rui, Wu Wanlin, Lu Canhui, Cölfen Helmut
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065, China.
Physical Chemistry, Department of Chemistry, University of Konstanz, Universitätsstraße 10, D-78457, Konstanz, Germany.
Adv Mater. 2022 Dec;34(51):e2206509. doi: 10.1002/adma.202206509. Epub 2022 Nov 7.
Nature provides numerous biomineral design inspirations for constructing structural materials with desired functionalities. However, large-scale production of damage-tolerant Bouligand structural materials with biologically comparable photonics remains a longstanding challenge. Here, an efficient and scalable artificial molting strategy, based on self-assembly of cellulose nanocrystals and subsequent mineralization of amorphous calcium carbonate, is developed to produce biomimetic materials with an exceptional combination of mechanical and photonic properties that are usually mutually exclusive in synthetic materials. These biomimetic composites exhibit tunable mechanics from "strong and flexible", which exceeds the benchmark of natural chiral materials, to "stiff and hard", which is comparable to natural and synthetic counterparts. Especially, the biomimetic composites possess ultrahigh stiffness of 2 GPa in their fully water-swollen state-a value well beyond hydrated crab exoskeleton, cartilage, tendon, and stiffest synthetic hydrogels, combined with exceptional strength and resilience. Additionally, these composites are distinguished by the tunable chiral structural color and water-triggered switchable photonics that are absent in most artificial mineralized materials, as well as unique hydroplastic properties. This study opens the door for a scalable synthesis of resilient biophotonic structural materials in practical bulk form.
大自然为构建具有所需功能的结构材料提供了众多生物矿化设计灵感。然而，大规模生产具有与生物可比光子学的耐损伤布氏结构材料仍然是一个长期挑战。在此，基于纤维素纳米晶体的自组装以及随后无定形碳酸钙的矿化，开发了一种高效且可扩展的人工蜕皮策略，以生产具有机械和光子特性特殊组合的仿生材料，而这些特性在合成材料中通常是相互排斥的。这些仿生复合材料展现出从“强且柔韧”（超过天然手性材料的基准）到“硬且刚”（与天然和合成对应物相当）的可调力学性能。特别地，这些仿生复合材料在完全水溶胀状态下具有2吉帕的超高刚度——这一数值远超水合蟹外骨骼、软骨、肌腱以及最硬的合成水凝胶，同时还具备卓越的强度和韧性。此外，这些复合材料的独特之处在于其可调的手性结构颜色和水触发的可切换光子学，这在大多数人工矿化材料中并不存在，以及独特的水塑性特性。这项研究为以实用块状形式可扩展合成弹性生物光子结构材料打开了大门。
