Tailoring Polymer Nanocomposite Properties by Nanoparticle Assembly

技术综述：基于聚合物接枝纳米粒子(NP)的新型材料是本提案的重点。由于无机纳米粒子和有机聚合物通常“不喜欢”对方，这些“毛茸茸”的粒子表现得像嵌段共聚物或两亲分子。因此，当它们被放置在有机基质中时，它们可以自组装成一系列的超结构。了解控制NP组装的因素，以及这种组装状态如何影响所得材料的性能是人们感兴趣的中心问题。作为这一全球努力的一部分，这项提案将涉及四个问题，其中两个涉及组装过程的基本原理，最后两个涉及NP组装状态与所产生的性质之间的关系：(I)能否批判性地描述管理嵌段共聚启发的“毛状”NP组装的材料科学？(2)是否可以使用外场(例如剪切)来引导NP组装，最终目的是设计具有定向传输特性的膜？(3)接枝的纳米粒子是否可以在界面上组装，以增容不相容的聚合物混合物？请注意，该提案在这里仅涉及实验方面，但将利用PIS小组中的两个平行的理论成果。因此，理论和实验相结合的方法将被用来理解这类新型材料应用的基本基础。非技术总结：这项提议的主要主张是，对纳米粒子空间分布的控制是创造具有可调性能的新聚合物材料的核心。因此，预计拟议的工作将对一系列新的应用产生关键影响，例如，自愈合材料、有机光伏、电池、净水膜、药物输送和先进光刻。这些变革性的研究活动与广泛的教育和外联活动相结合。在最近成功招收高中生和本科生进行暑期研究的激励下，PI将招募(并留住)未被充分代表的学生，包括女性和少数族裔，进入哥伦比亚大学化学工程系。该协会还与纽约城市学院和纽约科学院化学工程系合作，将大纽约地区的学者(教职员工和学生)、当地工业和国家实验室聚集在一起，举行一年一度的化学工程研讨会。我们的目标不仅是让学生进入当地的行业，也是为了吸引行业参与者进入哥伦比亚大学的更高学位和/或进修课程。

TECHNICAL SUMMARY: Novel materials based on polymer-grafted nanoparticles (NP) are the focus of this proposal. Since inorganic NPs and organic polymers typically "dislike" each other, these "hairy" particles behave like block-copolymers or amphiphiles. They can, therefore, self-assemble into a range of superstructures when placed in an organic matrix. Understanding the factors controlling NP assembly, and how this assembly state affects the properties of the resulting material are the central issues of interest. As part of this global effort, four questions will be addressed in this proposal, two of which relate to the fundamentals of the assembly process, while the last two refer to the relationship between the NP assembly state and resulting properties: (i) Can the materials science that governs block-copolymer-inspired "hairy" NP assembly be critically delineated ? (ii) Can NP assembly be directed using external fields, e.g., shear, with the ultimate goal of designing membranes with directional transport properties? (iii) Can grafted NPs be assembled at interfaces with the aim of compatibilizing immiscible polymer blends? Note that this proposal will only address experimental aspects here, but shall leverage two parallel theoretical efforts in the PIs group. Thus, a combined theory and experiment based approach will be used to understand the fundamental underpinnings of the applications of this novel class of materials.NON-TECHNICAL SUMMARY: The main assertion of this proposal is that the control over the spatial distribution of nanoparticles is central to creating new polymeric materials with tunable properties. Thus, it is expected that the proposed work will critically impact a range of novel applications, e.g., self-healing materials, organic photovoltaics, batteries, water purification membranes, drug delivery, and advanced lithography. These transformative research activities are coupled to extensive education and outreach activities. Motivated by recent successes in recruiting high school and undergraduate students for summer research, the PI will recruit (and retain) underrepresented students, both women and minorities, into the Chemical Engineering department at Columbia. The PI is also working with the Chemical Engineering department at the City College of New York and the New York Academy of Sciences to bring together academics in the Greater New York area (faculty and students), local industry and national laboratories in an annual chemical engineering symposium. The goal is, not only to place students into local industry, but also to attract industrial participants into higher degree and/or refresher programs at Columbia.