Continuous Acoustic Assembly of Metallic Nanoparticles in Microfluidic Systems

该项目将利用过去二十年开发的丰富的功能金属纳米颗粒，通过提供新的连续纳米制造方法，将纳米颗粒定向组装成定义明确的、多组分和多功能的纳米簇。这项工作的广泛目标是开发一套新的制造工具，用于可扩展、连续地生产球形或多面体形状的金属纳米颗粒的规则组装。定向组装将通过使用超声波将纳米颗粒包装在一起(声阻导入)完成，之后纳米颗粒将组织成高度规则的填充结构，以最大限度地增加单个纳米颗粒可用的能态数量(熵组装)。这种方法的一个优点是减少了污染。这项工作将发展连续纳米颗粒组装的基本基础，并将它们转化为原型制造过程。这些工艺将能够为包括医学、生物技术、光子学、催化和安全(防伪措施)在内的许多应用制造高价值产品。为了展示这项新技术的影响，该项目将创建定义明确的多功能纳米簇，用于药物输送和生物成像等高性能应用。纳米粒子组件的制造将在微流控系统中完成，其中包括超声驻波以实现纳米粒子的声熵组装，以及光化学交联反应以共价稳定物理组装的簇。为了实现这些目标，将完成几项关键任务--(I)研究导致纳米粒子连续声学和熵组装的基本过程，(Ii)对纳米粒子进行表面修饰，以实现多功能，包括胶体稳定性、配体和染料结合以及触发交联，(Iii)开发新的计量工具，使工艺优化能够最大限度地提高产量、产量和纯度，以及(Iv)研究在药物输送和生物成像中具有有用的多模式功能的纳米粒子模型组装，以最大限度地提高声熵纳米组装的科学和社会影响。这项研究计划将包括基础研究，以展示纳米级现象所特有的新制造原理，例如在没有限制固体边界的情况下粒子的熵组装，同时克服技术障碍，例如增强通常与纳米颗粒组装相关的传质受限动力学。该项目还将提供制造技术方面的几项创新，包括以异质颗粒、棒和细丝的形式连续和可扩展地生产定义良好的纳米颗粒组件，以及基于声阻抗谱和激光散射的新的纳米制造过程控制方法。

This project will exploit the wealth of functional metallic nanoparticles developed over the last two decades by providing new continuous nanomanufacturing methods for directed assembly of nanoparticles into well-defined, multicomponent and multifunctional nanoclusters. The broad goal of this work is to develop a suite of new manufacturing tools for the scalable, continuous production of regular assemblies of metallic nanoparticles that are either spherical or polyhedral in shape. Directed assembly will be accomplished through the use of ultrasonic waves to pack nanoparticles together (acoustophoresis), after which the nanoparticles will organize into highly regular, packed structures to maximize the number of energy states available to individual nanoparticles (entropic assembly). An advantage of this method is reducing contamination. This work will develop the fundamental underpinnings of continuous nanoparticle assembly and translate them into prototype manufacturing processes. These processes will be capable of fabricating high-value products for a number of applications including medicine, biotechnology, photonics, catalysis, and security (anti-counterfeiting measures). To demonstrate the impact of this new technology, this project will create well-defined, multifunctional nanoclusters for high performance applications such as drug delivery and bioimaging.The fabrication of nanoparticle assemblies will be accomplished in microfluidic systems that include ultrasonic standing waves to achieve acousto-entropic assembly of the nanoparticles and photochemical crosslinking reactions to covalently stabilize the physically assembled clusters. To achieve these aims, several key tasks will be completed--(i) study of the fundamental processes leading to continuous acoustic and entropic assembly of nanoparticles, (ii) surface modification of the nanoparticles to allow multi-functionality, including colloidal stability, ligand and dye binding, and triggered crosslinking, (iii) development of new metrology tools that permit process optimization to maximize throughput, yield and purity, and (iv) study of model nanoparticle assemblies that have useful, multimodal functionalities in drug delivery and bioimaging to maximize the scientific and societal impact of acousto-entropic nanoparticle assembly. This research program will include basic studies to demonstrate new manufacturing principles that are unique to nanoscale phenomena, such as entropic assembly of particles in the absence of confining solid boundaries, while at the same time overcoming technical barriers, such as enhancement of the mass transfer limited kinetics typically associated with nanoparticle assembly. This project will also provide several innovations in manufacturing technology including continuous and scalable production of well defined nanoparticle assemblies in the form of heterogeneous particles, rods and filaments, as well as new nanomanufacturing process control methodologies based on acoustic impedance spectroscopy and laser light scattering.