Multi-layered Nanocoating of Nano and Submicron Sized Particles at Large Scale

原子层沉积（ALD）工艺将进行大规模的超细颗粒的表面化学改性，并研究UVA/UVB透射率和自组装的改性颗粒的效用。 在研究的一个方面，多层和纳米层压陶瓷膜将使用流化床工艺放置在单个初级亚微米和纳米级无机颗粒的表面上。研究工作包括理解亚微米和纳米级颗粒的流化行为，这些颗粒受颗粒间力的影响，并作为动态聚集体，以及随后将单个初级颗粒流化为轻聚集体的能力。 这是首次尝试通过ALD在流化颗粒上放置纳米厚度多层膜。 选择防晒UVA/UVB系统（ZnO/TiO 2）以提供良好表征的应用，其具有用于测试非水性制剂（防晒乳液）中的复合粉末行为的确定性方法。 在研究的另一个方面，无机纳米膜将通过ALD放置在纳米球形颗粒的表面上，以控制它们的表面电荷（阴离子和阳离子）。 将研究含有等浓度的带相反电荷的纳米球的溶液用于离子自组装成纳米球“盐”。 调查将扩展到双层涂层的纳米尺寸的基底颗粒，其中内层赋予纳米粒子上的光学功能和外层赋予离子自组装的电荷功能。 在这种方式下，自组装的光子晶体阵列与控制衍射图案将进行研究。 该项目的总体目标是展示通过ALD在超细颗粒上的多层膜以及这种表面改性颗粒在配方和纳米制造阵列中的效用。这项新的研究提供了对纳米颗粒表面化学的大规模控制，以促进功能化纳米颗粒在配方中的使用，并用于制造新的组件。 待研究的纳米颗粒表面包覆方法能够广泛应用于许多系统。 本研究为两位博士提供了独特的教育经验。学生和大约20名本科生在三年的计划。 当地的工业合作伙伴ALD Nanosolutions已同意与学生合作（例如，通过顶点设计项目），以更好地了解研究的科学和应用方面，并促进技术转让。

Atomic Layer Deposition (ALD) processing will be carried out to modify the surface chemistry of ultrafine particles at large scale and to investigate the utility of the modified particles for UVA/UVB transmittance and self assembly. In one aspect of the research, multilayered and nanolaminated ceramic films will be placed on the surface of individual primary submicron and nanosized inorganic particles using a fluidized bed process. The research effort includes an understanding of the fluidization behavior of the submicron and nanosized particles that are affected by interparticle forces and that fluidize as dynamic aggregates, and the subsequent ability to nanocoat individual primary particles fluidizing as light aggregates. This is a first attempt to place nanothick multilayers on fluidized particles by ALD. A sunscreen UVA/UVB system (ZnO/TiO2) has been selected to provide for a well characterized application with definitive methods for testing the composite powder behavior in non-aqueous formulations (sunscreen lotions). In another aspect of the research, inorganic nanofilms will be placed on the surface of nanospherical particles by ALD to control their surface charge (anionic and cationic). Solutions containing equal concentration of oppositely charged nanospheres will be investigated for ionic self-assembly into nanospherical "salts". The investigation will be extended to bilayered coatings on nanosized substrate particles where the inner layer imparts optical functionality on the nanoparticles and the outer layer imparts charge functionality for ionic self assembly. In this manner, the self assembly of photonic crystalline arrays with controlled diffraction patterns will be investigated. The overall goal of the project is to demonstrate multi-layered films on ultrafine particles by ALD and the utility of such surface modified particles in formulations and nanofabricated arrays.This novel research provides for the large scale control of nanoparticle surface chemistry to facilitate the use of functionalized nanoparticles in formulations and for fabricating novel components. The nanoparticle surface coating method to be investigated is enabling and widely applicable to many systems. This research provides for a unique educational experience for two Ph.D. students and approximately 20 undergraduates over the three year program. A local industrial partner, ALD Nanosolutions, has agreed to work with the students (e.g., through capstone design projects) to better understand both the scientific and applied aspects of the research and to facilitate technology transfer.