Conjugated Polymer-Quantum Rod Nanocomposites in Well-Defined Nanoscopic Geometries

CBET-0824361将共轭聚合物与量子点或量子棒直接接触(即制备共轭聚合物-量子点(CP-QD)或共轭聚合物-量子棒(CP-QR)纳米复合材料)可在CP和QD或QR之间提供明确的界面，从而促进它们之间的有效电荷转移。然而，很少有研究集中在这种直接整合上，而局限于纳米几何结构的Cp-QR纳米复合材料也从未被探索过。该方案的目的是探索限制对Cp-QR纳米复合材料的光物理性质的影响。两种独特的策略将被用来限制Cp-QR纳米复合材料：(1)直接将纳米复合材料固定在高度有序的直柱形纳米孔阵列(即纳米多孔氧化铝薄膜)中；以及(2)将纳米复合材料限制在两个平行的平板之间，通过使两个覆盖着云母片的交叉圆柱形支架接触而形成，薄膜厚度从分子薄到数百纳米不等。研究成果将用于提高纳米科学教育的总体水平。将开展综合教育活动，使包括K-12学生在内的几个受众接触纳米科学的新知识，从而提高对其重要性的普遍认识。这项拟议的研究是基于涉及聚合物化学、聚合物物理、纳米制造技术和光物理的跨学科努力。这项工作的智力价值体现在创新研究中，利用纳米几何结构作为独特的物理环境来控制CPS的构象，进而调节CPS到QR的电荷转移，最终在纳米尺度上调节Cp-QR纳米复合材料的光物理性质。将追求四个具体的研究目标：(1)在合理设计的基础上制备Cp-QR纳米复合材料；(2)揭示外部纳米限制对Cp-QR纳米复合材料光物理性质的影响(第一种策略)；(3)建立从分子薄到几百纳米厚的Cp-QR薄膜的受限和剪切链构象与光物理性质之间的关联(第二种策略)；以及(4)开发用于光电子器件的Cp-QR纳米复合材料。这些发现还将增进对局限于纳米尺度的其他CP相关或QR相关纳米复合材料的理解。预计这项研究的结果将对纳米材料科学的进步做出重大贡献。拟议工作的更广泛影响包括在几个层面上加强纳米科学教育。女性本科生将被招募参加夏季纳米复合材料研究，从而加强该项目中代表性不足的群体的参与。还将为K-12教师开设暑期工作坊。高中实习生将为全国5-8年级的学生开发关于聚合物纳米材料的网络课程计划。这项活动最终将使中小学生接触到纳米世界。该项目产生的知识可能导致对国家安全和国防工业以及民用应用极其关键的新型纳米光电子器件的创造，从而将基础科学发现转化为有益于社会的技术。

CBET-0824361LinPlacing conjugated polymers in direct contact with quantum dots or quantum rods (i.e., preparation of conjugated polymer-quantum dot (CP-QD) or conjugated polymer-quantum rod (CP-QR) nanocomposites) provides a well-defined interface between CP and QD or QR, thus facilitating an efficient charge transfer between them. However, few studies have centered on such direct integration, and CP-QR nanocomposites confined in nanoscopic geometries have never been explored. The objective of this proposal is to explore the effects of confinement on the photophysical properties of CP-QR nanocomposites. Two unique strategies will be used to confine CP-QR nanocomposites: (1) directly immobilizing nanocomposites in highly ordered hexagonal arrays of straight cylindrical nanopores (i.e., a nanoporous alumina membrane); and (2) confining and shearing nanocomposites between two parallel plates, formed by bringing two crossed cylindrical mounts covered with mica sheets into contact, to film thicknesses ranging from molecularly thin to several hundred nanometers. The research findings will be used to enhance the general level of nanoscience education. Integrated educational activities will be pursued to expose several audiences, including K-12 students, to new knowledge in nanoscience, thereby promoting general awareness of its importance. The proposed research is based on an interdisciplinary effort that involves polymer chemistry, polymer physics, nanofabrication techniques, and photophysics. The intellectual merit of the work is manifested in the innovative studies of exploiting nanoscopic geometries as unique physical environments to control the conformation of CPs, which in turn regulates the charge transfer from CPs to QRs and, ultimately, the photophysical properties of CP-QR nanocomposites at the nanoscale. Four specific research goals will be pursued: (1) prepare CP-QR nanocomposites based on rational design; (2) reveal the effect of external nanoscopic confinement on the photophysical properties of CP-QR nanocomposites (first strategy); (3) establish correlations between the confined-and-sheared chain conformation and photophysical properties of CP-QR films ranging from the molecularly thin to several hundred nanometers thick (second strategy); and (4) exploit CP-QR nanocomposites for use in optoelectronic devices. The findings will also enhance understanding of other CP-related or QR-related nanocomposites confined at the nanoscale. The outcomes from the research are expected to contribute significantly to the advancement of nanomaterials science. The broader impacts of the proposed work include stronger nanoscience education across several levels. Female undergraduate students will be recruited for summer nanocomposite research, thus strengthening the involvement of an underrepresented group in the project. Summer workshops for K-12 teachers will also be created. High school interns will develop Web-based lesson plans on polymeric nanomaterials for 5th-8th graders nationwide. This activity will ultimately expose elementary- and middle-school students to the nano-world. Knowledge generated by this project may lead to the creation of novel nano-optoelectronic devices that are extremely critical to national security and the defense industry as well as civilian applications, thereby transitioning fundamental scientific discoveries into useful technologies that benefit society.