Mechanical Properties and Structure of Abalone: Self-Assembled Ceramic Nanostructures

鲍鱼的机械性能和结构：自组装陶瓷纳米结构

• 批准号: 0510138
• 负责人: Marc Andre Meyers
• 金额: $ 68.09万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510138&HistoricalAwards=false
• 关键词: Mechanical; Properties; Structure; Abalone; Self

NON-TECHNICAL DESCRIPTION: The synthetic materials (metals, polymers, ceramics, and composites) developed in research laboratories during the past century have revolutionized life. However, at present, the possibilities of designing and producing synthetic materials with improved performance are being exhausted. Therefore researchers are turning their attention to nature, trying to understand it better, with the goal of mimicking its designs. This emerging field of Biomimetics seeks to design properties into materials modeled after biological systems. The proposed study addresses the abalone shell that is highly prized as a source of nacre, or mother-of-pearl. Yet, is comprised of 95% chalk, which is weak and brittle. The complex nanostructure and microstructure of the shell are such that adding 5% of an organic glue leads to a toughness that is orders of magnitude higher than that of chalk. The goal of the proposed research is to understand, at the fundamental level, why the shell is so strong and to use this knowledge to develop a new generation of ceramic composites with superior properties. TECHNICAL DETAILS: A four-year program with strong characterization and analysis components will be carried out: development of new micro- and nano-mechanical testing methods to establish viscoelastic mechanical response of the protein layer(s) that act as an adhesive between tiles. This approach requires the use of atomic force microscopy, nanoindentation and nanoscratch tests, a miniaturized shear test (analogous to the meso scale test used by the PI), modeling mechanical responses through novel mechanisms incorporating viscoelastic response of organic layer; identification and quantification of the changes in the organic layers that occur after deformation using micro-Raman spectroscopy and FTIR, and identification of mechanisms by which tiles grow in "Christmas tree" pattern and transmit their orientation from level to level. Based on these observations, a detailed growth model for aragonite (the orthorhombic phase of CaCO3) will be developed. The ultimate goal is the use of biologically-inspired techniques to synthesize new materials. Research will be carried out at University of California San Diego, Universidad Nacional Autonoma de Mexico, and the Lawrence Livermore National Laboratory. Graduate and undergraduate students from San Diego and Mexico will be involved in the learning process, as well as high school students. The Preuss School, a charter high school that is designed as in intensive college preparatory educational program for low-income students in the grades 6-12, will be involved. These students come from families whose parents have not received college training. Two senior high school students will work during the school year (4-6 hrs/week, as allowed by The Preuss School) and full time during their summer breaks (6 weeks). It is emphasized that no abalone are harmed or killed for these experiments. This project is co-funded by the Office of International Science and Engineering and the Division of Materials Research.

非技术描述：在过去的世纪里，研究实验室开发的合成材料（金属、聚合物、陶瓷和复合材料）彻底改变了生活。然而，目前，设计和生产具有改进性能的合成材料的可能性正在被耗尽。因此，研究人员将注意力转向自然，试图更好地理解它，目的是模仿它的设计。仿生学这一新兴领域寻求将特性设计成模仿生物系统的材料。 这项拟议中的研究针对的是作为珍珠层或珍珠母来源的鲍鱼壳。然而，是由95%的白垩，这是脆弱和脆。壳的复杂纳米结构和微观结构使得添加5%的有机胶导致比白垩高几个数量级的韧性。拟议研究的目标是从根本上理解为什么外壳如此坚固，并利用这些知识开发具有上级性能的新一代陶瓷复合材料。技术规格：将开展一项为期四年的具有强大表征和分析组件的计划：开发新的微米和纳米机械测试方法，以建立蛋白质层的粘弹性机械响应，该蛋白质层作为瓷砖之间的粘合剂。这种方法需要使用原子力显微镜，纳米压痕和纳米划痕测试，一种小型化的剪切测试（类似于PI使用的中尺度测试），通过结合有机层粘弹性响应的新机制来模拟机械响应;使用显微拉曼光谱和红外光谱识别和量化变形后有机层发生的变化，以及识别瓷砖以“圣诞树”模式生长并将其方向从一层传递到另一层的机制。基于这些观察，文石（碳酸钙的正交相）的详细生长模型将被开发。 最终目标是使用生物启发的技术来合成新材料。研究将在加州圣地亚哥大学、墨西哥国立自治大学和劳伦斯利弗莫尔国家实验室进行。来自圣地亚哥和墨西哥的研究生和本科生以及高中生将参与学习过程。普鲁斯学校是一所特许高中，旨在为6-12年级的低收入学生提供密集的大学预科教育课程。 这些学生来自父母没有接受过大学教育的家庭。 两名高中生将在学年期间工作（4-6小时/周，由Preuss学校允许），并在暑假期间全职工作（6周）。 需要强调的是，这些实验不会伤害或杀死鲍鱼。该项目由国际科学与工程办公室和材料研究部共同资助。