Hierarchical and Shape-Intelligent Colloidal Particles via Lithographically Patterned Layered Precursors

纳米到微米尺寸颗粒的设计和合成一直是界面和材料科学的一个永恒主题。颗粒已被制备成具有一定范围的形状、尺寸和多分散性，更常见的是通过溶胶-凝胶或乳液聚合方法。核-壳、空-壳和混合粒子系统一直受到人们的高度关注。然而，对于聚合物颗粒，中空壳模板法和乳液聚合法在很大程度上限于球形颗粒。该项目旨在通过采用高通量颗粒制造方法来超越这些限制，该方法通过光刻方法提供形状，尺寸，尺寸分布和核壳结构的各种复杂性。 具体地，将探索基于光刻图案化的逐层（LbL）聚电解质的聚合物前体膜的新型颗粒，所述聚合物前体膜具有通过表面引发聚合（SIP）的接枝聚合物刷的顶层。两层之间的相相互作用参数对比将在选择性溶剂中实现“剥离和折叠”机制：LbL组分折叠以形成内部核和SIP作为外壳。 LbL和SIP方法的许多有据可查的化学、制造方法和应用都可以结合。应该可以在这些聚合物颗粒内分层分布化学物质，从而允许各向异性相分离的多相颗粒组合物。该协议的一个基本挑战是匹配的溶剂，温度和压力环境的动力学和热力学考虑，一旦颗粒从表面释放。各种界面敏感的光谱，散射，zeta电位和显微镜技术将被用来表征这些新的胶体材料。这些颗粒预期可用于作为纳米载体的分子、染料、无机纳米颗粒的包封，并且还用作研究聚合物和混合材料中的胶体现象的重要平台，所述聚合物和混合材料可通过理论和模拟研究来增强。该项目将提供可用于制药工业、显示器工业、以及环境或健康监测协议。举例来说：药物可以通过设计封装和释放;基于封装的纳米颗粒可以制造新的发光材料，并且具有各种人工形状和大小的颗粒可以用于模拟有害病毒和噬菌体。一些科学家和工程师将参与探索类似于半导体微处理器工业所用工艺的光刻技术的局限性，但将其应用于粒子生产和研究。一个重要的直接影响是教育和培训年轻科学家和研究人员，他们精通新材料的合成和表征，并开发高通量制造方法。两个高级博士在材料合成、胶体制造和表面表征方面有经验和资格的候选人将接受培训。高素质的本科生也将得到指导。Advincula研究小组的分析和材料专业知识涵盖了聚合物材料，混合材料和表面科学的不同领域，也是高中生科学和教育推广的有效平台。主要研究者（PI）将提供一个部门的课程，包括胶体颗粒的设计和使用以及材料研究中表面分析的重要性。PI将针对有才华的少数民族学生和妇女参与，这是PI自学术生涯开始以来的承诺。

TECHNICAL SUMMARY: The design and synthesis of nano- to micron-sized particles have been a perennial theme in interfacial and materials science. Particles have been prepared with a range of shape, size, and polydispersities more commonly through the sol-gel or emulsion polymerization methods. There has been a high interest on core-shell, hollow-shell, and hybrid particle systems. However, for polymer particles, hollow-shell templating and emulsion polymerization methods are largely limited to spherically shaped particles. This project aims to go beyond these limitations by employing a high-throughput particle fabrication method that offers various complexities in shape, size, size distribution, and core-shell architectures through lithographic methods. Specifically, novel particles based on lithographically patterned polymer precursor films of layer-by-layer (LbL) polyelectrolytes with a top layer of grafted polymer brushes by surface initiated polymerization (SIP) will be explored. The phase-interaction parameter contrast between the two layers will enable a "lift-off and fold-in" mechanism in a selective solvent: the LbL component folding in to form the interior core and the SIP as the outer shell. Many of the well-documented chemistries, fabrication methods, and applications of the LbL and SIP methods can be incorporated. It should be possible to distribute hierarchically the chemical species within these polymer particles allowing for anisotropically phase-separated multiphasic particle compositions. A fundamental challenge of the protocol is to match the kinetic and thermodynamic considerations of the solvent, temperature, and pressure environments once the particles are released from the surface. Various interfacial-sensitive spectroscopic, scattering, zeta potential, and microscopic techniques will be utilized to characterize these new colloidal materials. These particles are expected to be useful for the encapsulation of molecules, dyes, inorganic nanoparticles as nanocarriers and also serve as an important platform for the investigation of colloidal phenomena in polymeric and hybrid materials that can be augmented by theory and simulations studies.NON-TECHNICAL SUMMARY: The project will make available novel materials and products that can be used for the pharmaceutical industry, display industry, and environmental or health monitoring protocols. For example: drugs can be encapsulated and released by design; new light emitting materials can be made based on encapsulated nanoparticles, and particles with various artificial shapes and sizes can be used to mimic harmful viruses and bacteriophages. A number of scientists and engineers will be involved in exploring the limits of lithographic technologies similar to processes used for the semi-conductor microprocessor industry but applying it to particle production and investigation. An important immediate impact is the education and training of young scientists and researchers who are skilled in the synthesis and characterization of new materials combined with developing high-throughput fabrication methods. Two advanced Ph.D. candidates who are experienced and qualified in materials synthesis, colloidal fabrication, and surface characterization will be trained. Highly qualified undergraduate students will also be mentored. The analytical and materials expertise in the Advincula Research group encompasses different areas of polymer materials, hybrid materials, and surface science and has also been an effective platform for science and education outreach among high school students. The Principal Investigator (PI) will offer a Departmental course to include the design and uses of colloidal particles and the importance of surface analysis in materials research. The PI will target talented minority students and women to participate, a commitment by the PI since the beginning of his academic career.