Collaborative Research: Self-Assembly of Polymer Grafted Nanoparticles

合作研究：聚合物接枝纳米颗粒的自组装

• 批准号: 1033155
• 负责人: Athanassios Panagiotopoulos
• 金额: $ 27.43万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1033155&HistoricalAwards=false
• 关键词: Collaborative; Research; Self; Assembly; Polymer

AbstractIntellectual Merit: The focus of this proposal is novel materials created by isotropically grafting inorganic nanoparticles with organic polymers. Since the inorganicnanoparticles and organic polymers typically dislike each other, these hybrid particles behave like nanoparticle amphiphiles. By analogy to amphiphiles, these hybrid particles can self assemble into a range of superstructures of immediate relevance to many applications in the physical and biological sciences. Preliminary calculations suggest that this self assembly reflects a balance between the energy gain when particle scores approach versus the entropy loss of distorting the grafted polymers. The PIs plan to consider this issue theoretically and begin by delineating regions of parameter space where these self assembled structures are formed, and where they are equilibrium rather than temporally evolving structures amenable to kinetic control. Looking ahead, we ask how more complicated architectures, such as particles grafted with block copolymers might behave. This question is inspired by the large zoology of structures that have been predicted and obtained from triblock copolymers. The PIs also extend these ideas to other nanoparticle shapes, e.g., nanorods and nanosheets, and examine what shapes of nanoparticle assemblies may arise. Again, inspired by a broad range of experimental activities on block copolymers, the PIs query the role of external fields (e.g., flow, electric, magnetic) in directing the superstructures that form. The overarching goal is to a prior design isotropically decorated nanoparticles that can spontaneously assemble into progressively more complex superstructures. While these questions are of import from a fundamental viewpoint, they will be of particular practical interest since they provide unique means of controlling the global nanoparticle dispersion state, and hence the macroscopic properties, of polymer nanocomposites. The PIs propose a collaborative effort between two PIs, who will combine computer simulations and mean-field theory to tackle fundamental issues underpinning our nascent understanding of self-assembly (and directed assembly) of nanoparticle amphiphiles. The PIs have collaborated actively for over twenty years, and the PIs bring separate but complementary skill sets to the proposed research. The geographical proximity, and shared graduate students, also stronglyfacilitate this research and emphasizes the synergistic nature of the activities proposed.Broader Impact: The ability of decorated nanoparticles to self assemble into superstructures of arbitrary complexity, and the ability to direct this assembly process through the use of external fields, could fundamentally alter our ability to design nanoparticle assemblies (and hence polymer nanocomposites) with desired macroscale properties. Apart from these research activities, the PIs shall continue to develop REU programs targeting underrepresented minorities. The PIs shall utilize the fact that FAMU, a partner school, is a historically black school, and use this to recruit undergraduate students with the goal of retaining them in the sciences.

摘要智力优势：本提案的重点是通过无机纳米粒子与有机聚合物的各向同性接枝而产生的新型材料。由于无机纳米粒子和有机聚合物通常不喜欢对方，这些杂化粒子表现得像纳米粒子两亲体。与两亲体类似，这些杂交粒子可以自组装成一系列与物理和生物科学中的许多应用直接相关的上层结构。初步计算表明，这种自组装反映了粒子分数接近时的能量增益与扭曲接枝聚合物的熵损失之间的平衡。pi计划从理论上考虑这个问题，并开始描绘这些自组装结构形成的参数空间区域，以及它们是平衡的，而不是适合于动力学控制的临时演变结构。展望未来，我们想知道更复杂的结构，比如嵌段共聚物接枝的颗粒会有怎样的表现。这个问题的灵感来自于从三嵌段共聚物中预测和获得的大型结构动物学。pi还将这些想法扩展到其他纳米颗粒形状，例如纳米棒和纳米片，并检查可能出现的纳米颗粒组合的形状。同样，受到广泛的嵌段共聚物实验活动的启发，pi研究了外场（例如，流、电、磁）在指导形成的上层结构中的作用。首要目标是预先设计各向同性装饰的纳米粒子，使其能够自发地组装成越来越复杂的上层结构。虽然这些问题从基本观点来看是重要的，但它们将具有特别的实际意义，因为它们提供了控制全局纳米颗粒分散状态的独特方法，从而控制聚合物纳米复合材料的宏观性质。两位pi建议在两位pi之间进行合作，他们将结合计算机模拟和平均场理论来解决支持我们对纳米粒子两亲体自组装（和定向组装）的初步理解的基本问题。在过去的二十多年里，这些pi一直在积极合作，他们为拟议的研究带来了独立但互补的技能。地理上的接近和共享的研究生也极大地促进了这项研究，并强调了所提议的活动的协同性质。更广泛的影响：修饰纳米粒子自组装成任意复杂的超结构的能力，以及通过使用外场来指导组装过程的能力，可能从根本上改变我们设计具有理想宏观性能的纳米粒子组装（以及聚合物纳米复合材料）的能力。除了这些研究活动外，pi还将继续开发针对代表性不足的少数民族的REU项目。pi应利用FAMU作为合作学校，是一所历史上的黑人学校这一事实，并利用这一点招收本科生，目标是将他们留在科学领域。