Controlling Microstructure of Hybrid Thin Films through Flow-Induced Orientation

通过流动诱导取向控制混合薄膜的微观结构

• 批准号: 1562907
• 负责人: Luyi Sun
• 金额: $ 35.59万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1562907&HistoricalAwards=false
• 关键词: Controlling; Microstructure; Hybrid; Thin; Films

Composite materials are designed and processed to take synergistic advantage of the combined properties of the two component materials. Biomineralization, the process by which living organisms produce minerals, typically results in a composite system where the mineral forms the structural frame while an organic component assumes the biological function. Nacre, a shell material also known as mother of pearl, is a representative example, being composed of a large fraction of inorganic calcium carbonate (hard and brittle) and a small fraction of protein (soft and tough). Their combination in a layered structure leads to the outstanding mechanical properties in contrast to the individual components. Such carefully organized composites have inspired scientists to synthesize materials with a similar structure at a large scale for practical applications, but their efforts have not yet proven successful. The basic challenge is the difficulty of incorporating a large concentration of inorganic nanomaterials into a polymer system, and simultaneously achieving a high level of organization. This award supports fundamental research to explore a facile approach to prepare hybrid materials with a nacre-like microstructure and to achieve similar outstanding mechanical properties and other important functionalities. By taking advantage of flow-induced orientation of disc-like particles, the manufacturing of materials at a high rate appears to be possible. The composite films prepared through this approach should find application in packaging with improved barrier properties and corrosion resistance. Fully integrated within this project are activities to increase the interest in science and technology among the younger generation, particularly those in underrepresented groups.This research will lead to a thorough understanding of the fundamental mechanisms for the flow induced orientation and stacking of platelets that can help lead to optimal alignment of these particles in composite films to mimic the nacre structure. Factors such as flow rate, system viscosity, nanosheet concentration and aspect ratio, and related chemistry will be systematically investigated to address two fundamental questions. First, how do these factors affect the alignment and packing of nanosheets? Secondly, how will the interface between the nanosheets and the polymer binder affect the final thin film properties? In addition to the nacre-like structure and properties, the researchers also aim to further expand the scope to the formation of three-dimensional hybrid materials, such as bones, by properly tailoring the microstructure of the organic and inorganic components.

复合材料的设计和加工是为了利用两种组分材料的组合性能的协同优势。生物矿化是生物体产生矿物质的过程，通常会形成一个复合系统，其中矿物质形成结构框架，而有机成分承担生物功能。珠质是一种贝壳材料，也被称为珍珠之母，是一个代表性的例子，它由大部分无机碳酸钙（硬而脆）和一小部分蛋白质（软而韧）组成。它们在层状结构中的组合与单个组件相比具有突出的机械性能。这种精心组织的复合材料激发了科学家们在实际应用中大规模合成具有类似结构的材料，但他们的努力尚未被证明是成功的。基本的挑战是很难将大量的无机纳米材料结合到聚合物体系中，同时实现高水平的组织。该奖项支持基础研究，探索一种简单的方法来制备具有珍珠状微观结构的混合材料，并实现类似的杰出机械性能和其他重要功能。利用流动诱导的圆盘状颗粒取向，材料的高速率制造似乎是可能的。通过这种方法制备的复合薄膜在包装方面具有更好的阻隔性能和耐腐蚀性。在这个项目中充分纳入了提高年轻一代，特别是代表人数不足群体的年轻一代对科学和技术的兴趣的活动。这项研究将导致对流动诱导的血小板取向和堆积的基本机制的透彻理解，有助于导致这些颗粒在复合膜中模拟珍珠层结构的最佳排列。我们将系统地研究流速、体系粘度、纳米片浓度和宽高比等因素以及相关的化学性质，以解决两个基本问题。首先，这些因素如何影响纳米片的排列和包装？其次，纳米片与聚合物粘合剂之间的界面将如何影响最终的薄膜性能？除了珍珠状的结构和性能外，研究人员还打算通过适当地调整有机和无机成分的微观结构，进一步扩大其范围，以形成三维混合材料，如骨骼。