Surface Initiated Polymerization from Nanoparticles: Polymer Brushes on Nanoparticles as Polymeric Building Blocks

智力上的功绩。随着人们对纳米现象的兴趣与日俱增，人们需要了解如何合成和组装纳米材料的构件。关于无机纳米材料的合成，如半导体或磁性纳米粒子的合成，以及具有纳米级特征的有机大分子的合成，如嵌段共聚物微相分离结构域，有大量的信息。目前的一个重大挑战是创造新的纳米构建块，将无机纳米材料的有用的光学和磁性与有机纳米材料的多功能、反应性、自组装和机械性能结合在一起。拟议研究的目标是合成可用于组装更复杂材料的聚合物/纳米颗粒构建块。这项建议的具体目标是(1)开发适用于具有光致发光和磁性的纳米粒子(如CdSe和g-Fe2O3)的引发剂附着策略；(2)促进刷子合成的科学，包括深入研究纳米粒子引发剂的丙烯酸酯聚合和纳米粒子表面的嵌段共聚物的接枝；以及(3)开发从纳米粒子表面接枝反应单体的方法，这些单体然后可用于在互补的官能化表面组装纳米粒子的图案或构建纳米粒子的复杂组装。这项研究将有助于了解如何在纳米尺度上制备和组装物质。聚合物层将从表现出有趣的磁性和光学性质的纳米颗粒的外部生长出来，然后聚合物的化学功能将被用来选择性地与有图案的表面和其他纳米颗粒相互作用。这种合成和组装工艺可以作为工具来构建尺寸从几十纳米到微米的设备。该研究项目将在聚合物科学和纳米科学的重要领域为研究生和本科生提供培训和职业发展的机会，学生将获得重要的研究技能。该项目的PI和学生参与者还将通过参与加州大学戴维斯分校的COSMOS计划，努力促进高中阶段对聚合物/材料科学的学习。在项目期间的一个暑假，PI将设计并教授一门名为《聚合物与日常用品》的短期课程，提供给参与项目的高中生。参与的研究生将帮助完成一些实验室练习和实地考察。人们希望，早期对聚合物/材料科学的刺激体验将鼓励更多的学生在进入大学后继续学习科学(和材料科学)。

Intellectual Merit. With increased interest in nanoscale phenomena has arisen a need to understand how to synthesize and assemble the building blocks of nanoscale materials. There is much information on the synthesis of inorganic nanomaterials, such as semiconductor or magnetic nanoparticles, and there is much information on the synthesis of organic macromolecules that exhibit nanoscale features, such as block copolymer microphase separation domains. A significant challenge now is to create new nanosized building blocks that merge the useful optical and magnetic properties of inorganic nanomaterials with the versatile functionality, reactivity, self-assembly, and mechanical properties of organic nanomaterials. The objective of the proposed research is the synthesis of polymer / nanoparticle building blocks that could be used to assemble more complex materials. The specific aims of this proposal are (1) to develop initiator attachment strategies that are applicable to nanoparticles with photoluminescent and magnetic properties, such as CdSe and g-Fe2O3; (2) to further the science of brush synthesis including an in depth look at the polymerization of acrylates from nanoparticle initiators and the grafting of block copolymers from nanoparticle surfaces; and (3) to develop methods to graft reactive monomers from nanoparticle surfaces which can then be used to assemble patterns of nanoparticles on complementary functionalized surfaces or to build complex assemblies of nanoparticles.Broader Impact. This research will contribute to knowledge about how to prepare and assemble matter on the nanometer scale. Polymer layers will be grown from the exterior of nanoparticles that exhibit interesting magnetic and optical properties, and then the chemical functionality of the polymer will be used to interact the nanoparticles selectively with patterned surfaces and with other nanoparticles. Such syntheses and assembly processes could be used as tools to construct devices with sizes ranging from tens of nanometers to microns. The resulting materials could also be used as components of biological and chemical sensors, materials for flexible and energy efficient displays, or magnetic resonance and optical imaging agents.This research project will provide training and career advancement for graduate and undergraduate students in the important areas of polymer science and nanoscience, and the students will gain important research skills. The PI and student participants in this project will also work to promote learning about polymer / materials science at the high school level through involvement in the COSMOS Program at UC Davis. During one of the summers of the project period, the PI will design and teach a short course entitled "Polymers and Everyday Things" to be offered to the participating high school students. Participating graduate students will help out with some of the laboratory exercises and field trips. It is hoped that an early, stimulating experience with polymer / materials science will encourage more students to pursue studying science (and materials science) when they attend college.