NER: Large Scale Synthesis and Assembly of Micro- and Nanoparticles with Dipolar Charge and Anisotropic Shape

abstractcts - 0403462 - o。具有特定方向相互作用的微纳米级聚合物颗粒可以组装成先进的“智能”材料和消费产品，然而这种颗粒目前还不容易获得。本文介绍了两种大规模合成具有各向异性电荷或形状的新型聚合物颗粒的新技术。第一类粒子将具有永久的偶极矩和/或四极矩。合成技术是基于乳液和微乳液在恒定或交变电场存在下的聚合（或凝固）。这些粒子将表现出偶极子-偶极子相互作用，这将使它们定向自组装成具有远程定向的结构。将制造的第二种新型粒子是圆柱形聚合物微棒。PI已经发现了一种可扩展的工艺，通过剪切和“干燥”聚合物溶液中的乳化液滴来制造这种圆柱形颗粒。制备不同长宽比的胶体棒可以控制它们的取向、熵和诱导的偶极相互作用。这些各向异性粒子将用于组装各种先进材料，如离子和pH敏感凝胶、胶体液晶、不常见对称性的光子晶体和电流变流体。所建议活动的智力价值。两个原始的概念，为制造新的性质和相互作用的新型粒子的基本扩展。水中电各向异性粒子之间依赖于取向的非dlvo表面力引起了广泛的学术和工业研究人员的兴趣。对这些粒子的接触可能会导致对非dlvo力的新的基本见解。棒状粒子使熵自组织新现象的基础研究成为可能。新型的微纳米结构将通过这些粒子的工程组装而形成。这些结构包括由颗粒而不是分子形成的“胶体”液晶，具有新型对称性的光子晶体，强相互作用的水基电流变流体和材料，其中颗粒根据环境变化而组装或拆卸。拟议活动所产生的更广泛影响。该项目将首次允许大规模、高效和廉价地制造具有各向异性形状和/或定向相互作用的胶体颗粒。本科生研究项目、工业科学家拓展课程以及国内和国际合作也在计划之中。由此产生的新材料和技术的潜在受益者包括化学、制药和生物医学行业，以及制造显示器、光子学和光电子设备的公司。一些可能的应用是在数百万美元的行业中，例如用胶体液晶取代显示器中的分子液晶，以及开发具有更高粘度和更好光学性能的新型聚合物“乳胶”涂料。光子晶体和水基电流变流体可以在新兴的高技术中找到应用。用于医疗应用的新型“智能”离子敏感或生物分子敏感凝胶也可以制造出来。这将导致在纳米尺度上可扩展和高效的制造过程。

AbstractCTS-0403462O. Velev, North Carolina State UniversityMicro- and nanometer sized polymer particles possessing specific directional interactions can be assembled into advanced "smart" materials and consumer products, however such particles are not readily available to date. Two new techniques for large-scale synthesis of novel classes of polymer particles with anisotropic charge or shape are extended here. The first class of particles will have permanent dipolar and/or quadrupolar moments. The synthesis technique is based on polymerization (or solidification) of emulsions and microemulsions in the presence of constant or alternating electric field. These particles will exhibit dipole-dipole interactions that will make them directionally self-assemble into structures with long-range orientation. The second new class of particles that will be fabricated are cylindrical polymer microrods. The PI has discovered a scalable process for making such cylindrical particles by shearing and "drying" of emulsified droplets from polymer solution. Fabrication of colloid rods of different aspect ratios will allow controlling their orientational, entropic and induced dipolar interactions. These anisotropic particles will be used for the assembly of a variety of advanced materials such as ion- and pH sensitive gels, colloidal liquid crystals, photonic crystals of uncommon symmetry and electrorheological fluids.Intellectual merit of the proposed activity. Two original concepts for fabrication of new classes of particles with fundamentally novel properties and interactions are extended. The orientation dependent non-DLVO surface forces between electrically anisotropic particles in water could be of interest to a wide community of academic and industrial researchers. Access to these particles could lead to new fundamental insights into non-DLVO forces. The rod-like particles make possible fundamental research in new phenomena of entropic self-organization. New types of micro- and nanostructures will be formed by engineered assembly of these particles. These structures include "colloidal" liquid crystals from particles instead of molecules, photonic crystals with novel symmetries, strongly interacting water-based electrorheological fluids and materials where the particles assemble or disassemble in response to changes in their environment.Broader impacts resulting from the proposed activity. This project will for the first time allow the large-scale, efficient and inexpensive fabrication of colloidal particles with anisotropic shape and/or directional interactions. Undergraduate student research projects, an outreach course for industrial scientists, and national and international collaborations are also planned. Potential beneficiaries of the resulting novel materials and technologies include the chemical, pharmaceutical and biomedical industries, and companies making displays, photonics and optoelectronic devices. Some possible applications are in multi-million dollar industries, such as replacing the molecular liquid crystals in displays with colloidal liquid crystals, and developing new polymer "latex" paints with higher viscosity and better optical properties. Photonic crystals and water-based electrorheological fluids could find application in emerging high technologies. Novel "smart" ion-sensitive or biomolecule-sensitive gels for medical applications could also be fabricated. This will lead to scalable and efficient manufacturing processes at the nanoscale.