Collaborative Research: The Self-Assembly of Multicomponent Nanostructures

自然界中的许多显著特征，从蜘蛛丝的强度到植物叶子的捕光能力，都源于复杂的多组分建筑。这些生物纳米结构由多个离散的组件组成，这些组件以纳米级(十亿分之一米级)的精度组装成一个高度集成的功能系统。自组装提供了一种方便的、尽管往往是基于试验和错误的策略，以制造纳米级的单组分合成材料。然而，由于难以可靠地设计由多个精确定位的部件组成的自组装系统，这些系统很少表现出自然系统中所见的高水平的性能。为了应对这一挑战并朝着更高水平的功能性能发展，俄亥俄州立大学的Parquette教授和阿克伦大学的Modarelli教授正在开发策略，将多个离散的构建块自组装成多组件架构，作为太阳能转换的光电材料。创建可靠的策略来创建可与生物学中的复杂系统相抗衡的非共价体系结构，可能会使新技术能够解决可再生能源、温室气体转化和医学等领域的社会问题。此外，该项目还被用作一个平台，以提高公众对科学在解决这些问题方面所发挥的潜在作用的认识。研究团队继续在哥伦布科学与工业中心(COSI)举办科学展览，让年轻学生体验科学发现的亲身体验。此外，研究人员利用俄亥俄州立大学的REEL计划，除了在研究实验室为本科生提供机会外，还为大量本科生提供在教学实验室环境中进行纳米技术研究的机会。Parquette和Modarelli教授通过NSF HBCU-Rise计划和俄亥俄州立大学的SROP(暑期研究机会计划)为少数族裔学生提供纳米技术领域的研究经验。化学系的高分子、超分子和纳米化学计划支持Parquette和Modarelli教授的工作，旨在开发一种通用策略，将多个光电子元件组装成集成在单个纳米结构中的自我分类的域。这种方法使用顺序逐层策略来创建复合纳米结构，以将预先组装的系统组织到一个体系结构中。这些成分的形态、尺寸和位置排列与使用超快光谱技术测量的相应的光物理性质相关联。研究活动包括：(1)纳米管-聚合物复合材料的共同组装，展示了建立氧化还原级联的同轴、双连续的共轭聚合物阵列；(2)离散的、单体构建块的共同组装成由单独的、自组装的纳米结构组成的复合结构；(3)通过系综和单分子飞秒光谱测量组件的光物理性质；和(4)通过表面跟踪扫描电化学显微镜(ST-SECM)测量排列的纳米管共同组件的光电耦合。该项目将基础研究与外联和交流努力相结合，以吸引跨学科科学的不同学生群体，以及整个社区，展示纳米技术如何影响他们的生活。

Many of the remarkable features seen in nature, ranging from the strength of spider silk to the light-harvesting ability of plant leaves, arises from sophisticated, multicomponent architectures. These biological nanostructures are comprised of multiple, discrete components that are assembled with nanoscale (one billionth of a meter scale) precision into a highly integrated functional system. Self-assembly offers a convenient, albeit often trial and error-based strategy, to make single-component, synthetic materials in the nanoscale regime. However, these systems rarely exhibit the high level of performance seen in natural systems due to the difficulties in reliably designing self-assembling systems composed of multiple, precisely positioned components. To address this challenge and progress toward higher levels of functional performance, Professors Parquette of The Ohio State University and Modarelli of The University of Akron, are developing strategies to self-assemble multiple, discrete building blocks into multicomponent architectures to serve as optoelectronic materials for solar energy conversion. Creating reliable strategies to create non-covalent architectures that rival the sophisticated systems in biology may enable new technologies capable of addressing societal problems in areas such as renewable energy, greenhouse gas conversion, and medicine. Additionally, this project is used as a platform to enhance public awareness of the potential role that science plays in addressing these issues. The research team continues to present science exhibitions at the Columbus Center of Science and Industry (COSI) to allow younger students to experience the hands-on excitement of scientific discovery. Also, the investigators use Ohio State's REEL program to offer opportunities for large numbers of undergraduate students to perform nanotechnology research in a teaching laboratory environment in addition to providing opportunities for undergraduates in the research laboratory. Professors Parquette and Modarelli provide research experiences to minority students in the area of nanotechnology through the NSF HBCU-RISE program and through the SROP (Summer Research Opportunities Program) at OSU.The Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division supports the work of Professors Parquette and Modarelli, which aims to develop a versatile strategy to assemble multiple optoelectronic components into self-sorted domains that are integrated within a single nanostructure. This approach creates composite nanostructures using a sequential layer-by-layer strategy to organize pre-assembled systems into one architecture. The morphology, dimensions, and positional arrangement of the components are correlated with the corresponding photophysical properties, measured using ultrafast spectroscopic techniques. The research activities include: (1) the co-assembly of nanotube-polymer composites displaying a coaxial, bicontinuous array of conjugated polymers that establish a redox cascade; (2) the co-assembly of discrete, monomeric building blocks into composite structures comprised of separate, self-assembled nanostructures; (3) measurement of the photophysical properties of the assemblies via ensemble and single-molecule femtosecond spectroscopy; and (4) to measure photo-electrochemical coupling of aligned nanotube co-assemblies via surface-tracked scanning electrochemical microscopy (ST-SECM).This project integrates fundamental research with outreach and communication efforts to engage a diverse group of students in interdisciplinary science, and the community at large, to show how nanotechnology impacts their lives.