Vertically Oriented Anisotropic Nanoparticles in Polymer Matrices

聚合物基质中垂直取向各向异性纳米颗粒

• 批准号: 1507713
• 负责人: Russell Composto
• 金额: $ 58万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507713&HistoricalAwards=false
• 关键词: Vertically; Oriented; Anisotropic; Nanoparticles; Polymer

NON-TECHNICAL SUMMARY:To promote the progress of polymer science, this project is focused on polymer nanocomposites. Because they underlie so many applications, polymer-nanocomposite research impacts and improves technologies ranging from complex devices, such as energy producing solar cells, to everyday materials, such as lighter packaging. The fundamental issues that the project seeks to address are those that govern the assembly of anisotropic particles in block copolymers. Specifically, the project will produce vertically-oriented, anisotropic particles with controlled regular separations, and in so doing will advance understanding of nanorods and nanoplates in polymeric materials having special geometries such as nanocylinders in a matrix or alternating nanosheets. The resulting insights about how to self-assemble vertically oriented nanoparticles will enable the scientific community to explore a variety of anisotropic properties including molecular, electrical, and thermal transport. A successful outcome of the proposed research will be precise control over the vertical orientation and lateral spacing of nanorods and nanoplates in polymer nanocomposite films, which have potential benefits to society in areas of nanofiltration, sensing, barrier coatings and lighting. Besides producing a well educated, scientifically skilled work force, the integration of research and education benefits society at several levels. Besides graduate education, undergraduates from the US and abroad as well as local Philadelphia high school participants will benefit from research and mentoring. To reach a broad audience, researchers will participate annually in Nanoday@Penn and Philly Materials Day, which attract over 200 high school students and 2000 attendees, respectively. Furthermore, the annual Teachers Materials Science Workshop will continue as well as a unique partnership with Central High School, Philadelphia, which exposes a large minority student population to opportunities in STEM fields.TECHNICAL SUMMARY:The thermodynamic and dynamic principles that control vertical alignment of nanorods and nanoplates in block copolymer (BCP) films will be investigated. Anisotropic particles will be grafted with polymer brushes to control their interactions with other particles and BCP. Research objectives are to: (1) Vertically align nanorods in perpendicular cylindrical domains of block copolymers. Metallic, nanophosphor and semiconducting nanorods will be investigated in poly(styrene-b-2-vinyl pyridine) (PS-b-P2VP) and P2VP films. The effect of nanorod diameter and length on vertical orientation is of particular interest, as well as using binary mixtures of nanorods to direct them to specific microdomains. (2) Vertically align nanoplates in perpendicular lamella domains of block copolymers. Graphene oxide, nanophosphor and laponite nanoplates will be investigated in poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PS films. (3) Investigate the dynamics of nanorod assembly in homopolymer and block copolymer films during solvent annealing. Single particle tracking will be used to measure nanorod mobility. Field theoretic simulations modified to include dynamics will guide experiments and provide insight into the balance between thermodynamics and dynamics that differentiates the final morphology.The research leverages new and continuing collaborations to create novel particle-polymer assemblies, perform in situ characterization, and model vertically aligned polymer nanocomposites. Specifically, dispersion will be studied as a function of particle shape, size and surface chemistry, film thickness and interface interactions, and BCP composition and size. Three-dimensional field theoretic simulations will guide the choice of experimental parameters and provide a thermodynamic framework for understanding the interplay between particle and BCP orientation. BCP morphology will be determined by TEM, AFM and SAXS, particle location by TEM, FIB-SEM and depth profiling by RBS. GISAXS will be used to follow in situ structural evolution during solvent annealing. Optical properties will be characterized by UV-vis spectroscopy. This research benefits from unfunded collaborations with Sandia National Laboratories and the Advanced Light Source.

非技术概要：为了推动高分子科学的进步，本项目重点研究聚合物纳米复合材料。 由于它们是许多应用的基础，聚合物纳米复合材料的研究影响并改进了从复杂设备（例如发电太阳能电池）到日常材料（例如更轻包装）的技术。该项目寻求解决的基本问题是那些控制嵌段共聚物中各向异性颗粒组装的问题。具体来说，该项目将生产具有受控规则分离的垂直取向、各向异性颗粒，这样做将增进对具有特殊几何形状的聚合物材料中的纳米棒和纳米板的理解，例如基质中的纳米圆柱体或交替的纳米片。由此产生的关于如何自组装垂直取向纳米粒子的见解将使科学界能够探索各种各向异性特性，包括分子、电和热传输。该研究的成功成果将是精确控制聚合物纳米复合薄膜中纳米棒和纳米板的垂直方向和横向间距，这对纳滤、传感、阻隔涂层和照明领域的社会具有潜在的好处。除了培养受过良好教育、具有科学技能的劳动力之外，研究和教育的结合还可以在多个层面上造福于社会。除了研究生教育外，来自美国和国外的本科生以及费城当地高中的参与者也将从研究和指导中受益。为了吸引更广泛的受众，研究人员将每年参加 Nanoday@Penn 和费城材料日，分别吸引超过 200 名高中生和 2000 名与会者。此外，年度教师材料科学研讨会将继续进行，并与费城中央高中建立独特的合作关系，为大量少数族裔学生提供 STEM 领域的机会。 技术摘要：将研究控制嵌段共聚物 (BCP) 薄膜中纳米棒和纳米板垂直排列的热力学和动力学原理。各向异性颗粒将接枝聚合物刷，以控制它们与其他颗粒和 BCP 的相互作用。研究目标是：（1）在嵌段共聚物的垂直圆柱域中垂直排列纳米棒。将在聚（苯乙烯-b-2-乙烯基吡啶）（PS-b-P2VP）和 P2VP 薄膜中研究金属、纳米磷和半导体纳米棒。纳米棒直径和长度对垂直方向的影响特别令人感兴趣，以及使用纳米棒的二元混合物将它们引导到特定的微域。 (2)在嵌段共聚物的垂直片层域中垂直排列纳米板。氧化石墨烯、纳米磷光体和合成锂皂石纳米片将在聚（苯乙烯-b-甲基丙烯酸甲酯）（PS-b-PMMA）和 PS 薄膜中进行研究。 (3) 研究溶剂退火过程中均聚物和嵌段共聚物薄膜中纳米棒组装的动力学。单粒子追踪将用于测量纳米棒的迁移率。修改后包含动力学的场论模拟将指导实验，并深入了解热力学和动力学之间的平衡，从而区分最终形态。该研究利用新的和持续的合作来创建新型颗粒聚合物组件，进行原位表征，并对垂直排列的聚合物纳米复合材料进行建模。具体而言，将研究分散性作为颗粒形状、尺寸和表面化学、膜厚度和界面相互作用以及 BCP 组成和尺寸的函数。三维场论模拟将指导实验参数的选择，并为理解粒子和 BCP 方向之间的相互作用提供热力学框架。 BCP 形态将通过 TEM、AFM 和 SAXS 确定，颗粒位置将通过 TEM、FIB-SEM 确定，深度分析将通过 RBS 确定。 GISAXS 将用于跟踪溶剂退火过程中的原位结构演化。光学特性将通过紫外-可见光谱来表征。这项研究受益于与桑迪亚国家实验室和先进光源的无资助合作。