Research of Bio-nano-aragonite-fiber Structures of Anodontia Edentulas Shell
Molluscan shell is a kind of biocomposite with excellent fracture strength and fracture toughness, which can be attributed to its particular nanostructures. The scanning electron microscope observation of an Anodontia edentulas shell showed that the shell is a kind of bioceramic composite consisting of aragonite layers and collagen protein matrix. The aragonite layers are parallel with the surface of the shell and consist of long and thin aragonite sheets. The aragonite sheet consists further of smaller aragonite fibers. The diameter of the aragonite fibers is of nanometer scale. The observation also showed that the aragonite fibers in different aragonite layers possess different orientations, which compose different nano-aragonite-fiber structures, such as intersectant and helicoidal ones. The toughness enhanced mechanisms of the shell were investigated based on the comparative analyses and tests of the maximum pullout forces between these structures and ° 0 structure. The strength enhanced mechanisms of the shell was researched based on the analysis of the ultimate strength of the nano-aragonite fibers. The investigated results showed that, compared with the conventional ° 0 structure, the intersectant and helicoidal structures can markedly increase the maximum pullout forces of the nano-aragonite fibers, and as a result, enhance the fracture toughness of the shell, and that the nanometer scale of the aragonite fibers can practically enhance the fracture strength of the shell.
Anodontia edentula shell Nano-aragonite fiber Intersectant and helicoidal structures Fracture toughness and fracture strength
陈斌 彭向和 孙士涛
重庆大学资源及环境科学学院工程力学系,重庆400044
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）