NIRT: One-,Two- and Three-Dimensional Superstructured Materials from Well-Defined, Complex Nanoscale Components

这个纳米级跨学科研究团队（NIRT）项目由美国国家科学基金会材料研究、化学、化学和运输系统部门共同资助，将开发合成策略和表征协议，用于生产和研究由稳定纳米颗粒组件组成的一维、二维和三维超结构。合成方法包括在溶液和衬底上系统地排列共聚物的交联组件，作为坚固的核-壳构建块，制造一维中观尺度（~100 nm至~1 mm），二维微观尺度（~1 mm至~100 mm）和三维宏观尺度（100 mm）的物体，每个物体都由纳米级构建块组成。其结果将是创建完全独特的复合形态，这是无法在共聚物的相图直接访问。这种策略模仿了纳米尺度的化学控制，而纳米尺度目前是生命系统的专属领域。利用纳米级有机基超结构作为支架来引发无机材料和生物大分子的纳米晶生长将是研究的关键目标。对有机上层结构促进结晶和共结晶的机理进行了详细的研究。需要测试的假设包括：(1)有机纳米粒子将被组装成定义良好的一维、二维和三维超结构，适合制造成有用的设备应用；(2)这样的上层结构将呈现界面接触，这些界面接触模板化结晶事件，以产生独特的可控纳米晶相，从表面或通过共结晶引发；(3)有机超结构和纳米晶材料的性质将导致其具有独特的物理、光学、磁性和力学性能。拟议活动的教育和研究方面将跨越多个学科（有机化学、生物学、物理化学、聚合物物理、化学和机械工程以及材料科学），以有效地解决由两个或多个纳米尺度结构组成的一维、二维和三维超结构的研究，以及模板化的无机/有机纳米晶体材料。拟议中的研究有丰富的机会影响教育。学生将受益于跨学科、多地点的研究活动。在华盛顿大学为K-8教师开发的外展课程（2001年秋季）将在参与机构得到加强和实施。这个NIRT的重点还为纳米科学和纳米技术的好处的社会教育创造了一个有效的平台。例如，所提出的纳米结构固体可能代表新的先进医学材料，例如用于控制药物释放的“智能”水凝胶涂层，以及用于组织工程的支架。这些材料也可能是下一代先进的分离介质、坚韧的光学透明固体、催化剂或纳米复合材料，用于制造纳米或微机械设备。热响应存储器器件和用于悬臂式传感器器件的复杂纳米涂层是将研究一维、二维和三维超结构的特殊应用。此外，所提出的材料将被评估为纳米级表面，从无机盐或生物大分子的结晶可以启动。作为骨生长中发现的纳米晶相的模型系统，上层结构的可控共结晶将被研究。

This Nanoscale Interdisciplinary Research Team (NIRT) project, co-funded by the National Science Foundation Divisions of Materials Research, Chemistry, and Chemical and Transport Systems, will develop synthetic strategies and characterization protocols for the production and study of one-, two- and three-dimensional superstructures composed of stabilized nanoparticle assemblies. The synthetic approach involves the systematic ordering, in solution and on substrates, of crosslinked assemblies of copolymers, as robust core-shell building blocks, to manufacture 1-dimensional meso-scale (~100 nm to ~1 mm), 2-dimensional micro-scale (~1 mm to ~100 mm) and 3-dimensional macro-scale (100 mm) objects, each comprised of nanoscopic building blocks. The result will be the creation of entirely unique composite morphologies that are not accessible in the phase diagrams of the copolymers directly. This strategy mimics the control of chemistry at the nanometer scale that is currently the exclusive province of living systems. Utilization of the nanoscale organic-based superstructures as scaffolds for the initiation of nanocrystalline growth of inorganic materials and biomacromolecules will be a key goal of the investigation. The mechanisms by which the organic superstructures promote crystallization and co-crystallization will be studied in detail. The hypotheses to be tested include: (1) organic nanoparticles will be assembled into well defined one-, two- and three-dimensional superstructures, suitable for fabrication into useful device applications; (2) such superstructures will present interfacial contacts that template the crystallization events to produce unique and controllable nanocrystalline phases, initiated from a surface or via co-crystallization; (3) the nature of the organic superstructures and the nanocrystalline materials will result in unique physical, optical, magnetic, and mechanical properties.The educational and research aspects of the proposed activities will cross several disciplines (organic chemistry, biology, physical chemistry, polymer physics, chemical and mechanical engineering, and materials science) to address effectively the study of one-, two-, and three-dimensional superstructures, composed of two or more nanoscale constructs, and of templated inorganic/organic nanocrystalline materials. The proposed research is rich with opportunities to impact education. Students will benefit through interdisciplinary, multi-site research activities. An outreach course developed (Fall 2001) at Washington University for K-8 teachers will be enhanced and implemented at the participating institutions. The focus of this NIRT also creates an effective platform for societal education of the benefits of nanoscience and nanotechnology. For example, the proposed nanostructured solids may represent new advanced materials for medicine, such as "smart" hydrogel-like coatings for controlled release of drugs, and scaffolds for tissue engineering. These materials may also be the next generation of advanced separation media, tough optically clear solids, catalysts or nanocomposites used in the fabrication of nano- or micro-mechanical devices. Thermally-responsive memory devices and complex nanoscopic coatings for cantilever-based sensor devices are particular applications that will be investigated for the 1-, 2-, and 3-dimensional superstructures. Additionally, the proposed materials will be evaluated as nanoscopic surfaces from which the crystallization of inorganic salts or biomacromolecules can initiate. The controlled co-crystallization of the superstructures will be investigated, as a model system for the nanocrystalline phases found in bone growth.