The Role of Grafting Mechanism on the Self-Assembly and Properties of Polymer Nanocomposites

接枝机制对聚合物纳米复合材料自组装和性能的作用

• 批准号: 1709061
• 负责人: Sanat Kumar
• 金额: $ 59.2万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709061&HistoricalAwards=false
• 关键词: Role; Grafting; Mechanism; Self; Assembly

NON-TECHNICAL SUMMARY: The addition of inorganic nanoparticles (NPs) to a polymer (i.e. a plastic material) can result in hybrid materials with highly improved properties. A classic example is that, while rubber (as e.g. in an eraser) has extremely poor wear resistance, the addition of silica nanoparticles causes the wear resistance to go up so much that a car can drive with tires that last over 50,000 miles. While such property improvements are what drive developments in the field of polymer nanocomposites, the inherent problem is that the nanoparticles are chemically so different from the polymer (a hydrocarbon material) and thus have a strong tendency to separate from each other akin to a water-oil suspension. Thus, the desirable, favorable property improvements that can only be realized by the intimate mixing of the polymer and the NPs become hard to realize on a routine basis. The work here proposes to remedy this problem by chemically grafting polymer chains onto the NPs so that the inorganic particle surface can be "shielded" from the polymer, thus allowing miscibility to be obtained. In particular, the work focuses on two strategies for this grafting: either grafting fully formed chains to the surfaces, or growing the chains piece-by-piece from the surface. Which of these strategies allows better control over particle-polymer miscibility and therefore improve properties the most is the focus of this research. In addition to this technical emphasis, the proposed work will also stress the broad, interdisciplinary education of students and the recruitment and retention of women and minority students into STEM programs by attracting high-school and undergraduate students into engineering research activities in the PI's laboratory.TECHNICAL SUMMARY: The focus of this proposal is on the self-assembly of polymer-grafted nanoparticles (NPs) in a polymer matrix with the goal of impacting the behavior of the resulting hybrid (or composite) material. This physical situation has relevance to improved performance in, for example, rubber tires and epoxies (which are used in electronic packaging and computer chip applications). This underpinning question will be studied through the exploration of three test-beds by judiciously combining theory and experiments. In particular, emphasis will be placed on role of the mechanism by which chains are grafted onto NP surfaces on the final material properties, i.e., whether the chains are preformed and attached to the surface or if the chains are grown link-by-link from the surface. It is expected that the former mechanism will yield a more uniform polymer coverage on the NP surface. The consequence of these differences in surface coverage on the assemblies formed and the resulting properties is the ultimate focus of this work. These research activities are coupled to extensive education and outreach activities. A major focus will be to recruit underrepresented students (both women and minorities) at both the undergraduate and graduate levels. It is planned to grow both the current summer high-school research program, and also the research-experiences-for-undergraduates program during the schoolyear, with the goal of recruiting (and hopefully retaining) women and minorities into STEM efforts.

非技术摘要：将无机纳米颗粒（NP）添加到聚合物（即塑料材料）中会导致具有高度改进特性的混合材料。一个经典的例子是，虽然橡胶（例如在橡皮擦中）具有极差的耐磨性，但添加二氧化硅纳米颗粒会导致耐磨性上升，以至于汽车可以驾驶持续50,000英里的轮胎。 尽管这种性质改进是在聚合物纳米复合材料领域推动发展的方法，但固有的问题是，纳米颗粒在化学上与聚合物（碳氢化合物材料）如此不同，因此具有与水油悬浮液相同的彼此分离的强烈趋势。因此，只有通过聚合物和NP的亲密混合才能实现的理想，有利的财产改进，在常规的基础上很难实现。这里的工作提议通过将聚合物链化学上的聚合物链上的NPS来解决这个问题，以便可以从聚合物中“屏蔽”无机颗粒表面，从而可以获得可质的能力。特别是，该作品着重于这种嫁接的两种策略：将完全形成的链条移植到表面，或者从表面逐件构成链条。这些策略中的哪种可以更好地控制粒子聚合物的混杂性，因此最大的特性是这项研究的重点。 In addition to this technical emphasis, the proposed work will also stress the broad, interdisciplinary education of students and the recruitment and retention of women and minority students into STEM programs by attracting high-school and undergraduate students into engineering research activities in the PI's laboratory.TECHNICAL SUMMARY: The focus of this proposal is on the self-assembly of polymer-grafted nanoparticles (NPs) in a polymer matrix with the goal of影响所得混合（或复合）材料的行为。这种身体状况与改善橡胶轮胎和环氧树脂的性能相关（用于电子包装和计算机芯片应用程序）。通过明智地结合理论和实验，将通过探索三个测试床来研究这个基础问题。特别是，将重点放在链条上的链条上的机理上的作用，即在最终材料特性上移植到NP表面上，即是否预先形成并附着在表面上，还是链条从表面链接起来。预计以前的机制将在NP表面产生更均匀的聚合物覆盖率。这些成型组件的表面覆盖范围以及所得属性的结果是这项工作的最终重点。这些研究活动与广泛的教育和外展活动相结合。主要重点是在本科和研究生级别招募代表性不足的学生（妇女和少数民族）。 计划在校长期间发展当前的夏季高中研究计划，以及在校长的研究经验计划，目的是招募（并希望保留）妇女和少数群体进入STEM努力。

项目成果

Detecting bound polymer layers in attractive polymer–nanoparticle hybrids

检测有吸引力的聚合物与纳米颗粒混合物中的结合聚合物层

• DOI: 10.1039/d1nr02395k
• 发表时间: 2021
• 期刊: Nanoscale
• 影响因子: 6.7
• 作者: Emamy, Hamed;Starr, Francis W.;Kumar, Sanat K.
• 通讯作者: Kumar, Sanat K.

Assembly of Polymer-Grafted Nanoparticles in Polymer Matrices

• DOI: 10.1021/acsnano.0c05495
• 发表时间: 2020-10-27
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Koh, Clement;Grest, Gary S.;Kumar, Sanat K.
• 通讯作者: Kumar, Sanat K.

Impact of the Distributions of Core Size and Grafting Density on the Self-Assembly of Polymer Grafted Nanoparticles

• DOI: 10.1021/acs.macromol.7b01093
• 发表时间: 2017-10-10
• 期刊: MACROMOLECULES
• 影响因子: 5.5
• 作者: Bachhar, Nirmalya;Jiao, Yang;Kumar, Sanat K.
• 通讯作者: Kumar, Sanat K.

Role of Grafting Mechanism on the Polymer Coverage and Self-Assembly of Hairy Nanoparticles

• DOI: 10.1021/acsnano.7b02657
• 发表时间: 2017-07-01
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Asai, Makoto;Zhao, Dan;Kumar, Sanat K.
• 通讯作者: Kumar, Sanat K.

Compatibilizing Immiscible Polymer Blends with Sparsely Grafted Nanoparticles

• DOI: 10.1021/acs.macromol.0c02108
• 发表时间: 2020-12-08
• 期刊: MACROMOLECULES
• 影响因子: 5.5
• 作者: Alkhodairi, Husam;Russell, Sebastian T.;Kumar, Sanat K.
• 通讯作者: Kumar, Sanat K.