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

技术综述：纳米到微米级颗粒的设计和合成一直是界面科学和材料科学中的一个长期主题。更常见的是通过溶胶-凝胶或乳液聚合方法制备具有各种形状、大小和多分散性的颗粒。人们对核壳、中空壳和混合粒子系统有很高的兴趣。然而，对于聚合物粒子，中空壳层模板和乳液聚合方法在很大程度上局限于球形粒子。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在形状、大小、大小分布和核壳结构方面提供各种复杂性。具体地说，将探索基于表面引发聚合(SIP)的具有顶层接枝聚合物刷子的逐层(LBL)聚电解质的光刻图案聚合物前驱体薄膜的新型颗粒。两层膜之间的相作用参数对比将在选择性溶剂中实现一种“提离和折叠”机制：LbL组分折叠形成内核，而SIP组分作为外壳。许多有充分记录的化学成分、制造方法和LBL和SIP方法的应用都可以结合在一起。应该可以在这些聚合物颗粒内分级分布化学物种，从而允许各向异性相分离的多相颗粒组成。该方案的一个根本挑战是，一旦颗粒从表面释放出来，就必须符合溶剂、温度和压力环境的动力学和热力学考虑。各种界面敏感的光谱、散射、Zeta电位和显微技术将被用来表征这些新的胶体材料。这些颗粒有望用于将分子、染料、无机纳米颗粒作为纳米载体进行封装，也可以作为研究聚合物和杂化材料中胶体现象的重要平台，可以通过理论和模拟研究来加强。非技术概述：该项目将提供可用于制药工业、显示器工业和环境或健康监测协议的新型材料和产品。例如：药物可以通过设计进行封装和释放；可以基于包裹的纳米颗粒制造新的发光材料，各种人工形状和大小的颗粒可以用来模仿有害的病毒和噬菌体。一些科学家和工程师将参与探索光刻技术的极限，类似于用于半导体微处理器行业的工艺，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的科学家和研究人员，他们精通新材料的合成和表征，并开发高通量制造方法。将培训两名在材料合成、胶体制造和表面表征方面经验丰富和合格的高级博士候选人。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，也是在高中生中推广科学和教育的有效平台。首席调查员(PI)将开设一门系级课程，包括胶体颗粒的设计和使用，以及表面分析在材料研究中的重要性。PI将以有才华的少数族裔学生和女性为目标参与，这是PI自他的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.