贝壳珍珠母是一种典型的无机/有机复合生物材料,通常位于软体动物盔甲的内层来抵御捕食者的捕食和外力的侵扰,体现了优异的力学性能,实现了强度和韧性的完美结合.它由95%(体积比)的文石碳酸钙和5%(体积比)的生物高聚物规则堆叠而成,呈现出独特的"砖泥"结构,其优异的力学性能和这种独特的结构有重要联系.因此,贝壳珍珠母常被用来作为仿生材料设计的模板,引起了化学家、材料学家和生物学家的强烈关注.本文详细介绍了贝壳珍珠母的多尺度微观结构及其增强增韧机制;以仿生复合材料中无机物的种类作为分类依据,系统地总结了仿贝壳珍珠母层状复合材料的发展现状;从仿贝壳珍珠母层状材料的性能出发,探讨了其在轻质高强、阻燃、气障、传感器和超级电容器等领域的应用;简要地总结了现阶段仿贝壳珍珠母层状复合材料的发展优势以及遇到的挑战,为新一代仿贝壳珍珠母材料的研究提供依据.
Nacre is a typical inorganic/organic composite produced by some mollusks as an inner shell layer of their armor systems to protect themselves from predators and other mechanical forces, which exhibits excellent mechanical performance, including high strength and high toughness at the same time. Nacre can also make up the outer coating of pearl to make which high iridescence. Nacre is composed of large fraction of inorganic aragonite calcium carbonate(95vol%) and small fraction of organic biopolymers(5vol%) with highly ordered hierarchical arrangement which is usually called as "brick and mortar" structure. Although nacre mostly consists of a fragile mineral, its toughness is three orders of magnitude higher than that of calcium carbonate in the form of aragonite. The excellent mechanical properties of nacre are highly related to its unique hierarchical structure. In this review, the hierarchical structure of nacre and its strengthening and toughening mechanisms are described from different length scale in detail. Lots of researches have demonstrated that mechanisms such as plastic deformation at the crack tip, crack deflection, crack blunting, pull-out at micro scale and nanoasperities on the tablet surface, mineral bridges, viscoplastic deformation of the organic material at nano scale greatly dissipate energy to make natural nacre stronger and tougher. Besides, recent advances in nacre-inspired artificial materials are summarized here based on the classification of inorganic building blocks including ceramic, clay, graphene and calcium carbonate. Ceramics are always used as the inorganic building blocks in artificial nacre owing to its high strength, high stiffness, low density and low cost, which can improve the application potential of such materials. Clay is chosen here due to its wide distribution and original plate structure, which makes artificial nacre easier to synthesis. Graphene show extremely high strength and modulus, up to 130 and 1000 GPa respectively, thus graphene is chosen to fabric