Functional Assemblies of Block Copolymers and Polymer-Stabilized Nanoparticles

光子学、信号处理、生物成像和传感领域对先进材料的需求刺激了纳米级调谐材料特性的研究领域的发展。嵌段共聚物是一种具有显著自组织倾向的合成分子，具有各种形态的复杂胶体结构，包括胶束和囊泡。金属和半导体纳米粒子由于其独特的光学和电子特性，可以作为尺寸的函数进行调节，因此作为各种纳米结构材料的基石，它们是令人兴奋的候选者。对于器件和先进材料的应用，在聚合物和纳米复合材料中控制纳米颗粒和嵌段共聚物的组装是一个关键的挑战。

The need for advanced materials for photonics, signal processing, biological imaging, and sensing has spurred a growing field of research into tuning material properties at the nano-scale. Block copolymers are synthetic molecules with a remarkable tendency to self-organize into complex colloidal structures of various morphologies, including micelles and vesicles. Metallic and semiconductor nanoparticles are exciting candidates as building blocks for a diverse range of nanostructured materials, due to unique optical and electronic properties that can be tuned as a function of size. For applications in devices and advanced materials, controlling the assembly of nanoparticles and block copolymers in polymeric and nanocomposite materials is a critical challenge. My research program focuses on developing new methods for hierarchical organization of block copolymers and metal and semiconductor nanoparticles in polymer systems, both in thin films and colloids. Our strategy for nanoparticle assembly utilizes hybrid building blocks consisting of nanoparticles encapsulated inside stable polymeric micelles. We use the polymeric brush layer surrounding each nanoparticle to harness various spontaneous structure-forming processes, resulting in controlled nanoparticle self-assembly on multiple length scales. These bottom-up processes can also be coupled to top-down methodologies such as microcontact printing and microfluidics, in order to exercise external handles on size, structure, and complexity. We also seek to understand the collective optical properties of the resulting polymer-nanoparticle assemblies, and how these properties relate to structure on various length scales. Through the combined development of structure control and determination of structure-property relations in polymer-nanoparticle materials, we will establish methodologies for tuning function toward various applications, including photonic circuit elements, chemical and temperature sensors, and multifunctional drug-delivery vehicles.