权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Vaporization of Nanoparticles in Low Temperature Plasmas

纳米粒子在低温等离子体中的汽化

基本信息

批准号：
1702334
负责人：
Elijah Thimsen
金额：
$ 24.9万
依托单位：
Washington University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1702334&HistoricalAwards=false
关键词：
Vaporization Nanoparticles Low Temperature Plasmas

项目摘要

This award will support computational and experimental research towards understanding the mechanisms for synthesis of nanomaterials in low temperature plasmas. The high chemical reactivity of low temperature plasmas (LTPs) -- a mix of free interacting charged and neutral particles -- presents a tremendous opportunity for producing novel materials. With the theoretical limits for processing materials into new configurations via interactions with LTPs still unknown, there is also a chance for experimental discovery of novel processes to alter materials in unexpected ways. The use of LTPs in manufacturing of nanomaterials is ubiquitous, for example, in producing integrated circuits used in computers or in developing advanced electricity storage batteries. Fundamental knowledge of the formation and growth of nanoparticles in low temperature plasma is, thus, essential to the further improvement of advanced manufacturing processes. This project will explore a new aerosol mechanism in LTPs that has not been previously considered. The mechanism allows for the production of monodispersed nanoparticles comprised of materials for which production methods are currently not known. In LTPs, nanoparticles can be vaporized as a result of ion bombardment. The vaporization results in a supersaturated vapor. The supersaturated vapor, in turn, condenses back onto particles in the plasma or nucleates new clusters. This process of vaporization in the plasma followed by condensation can result in a monodispersed size distribution. In fact, such a process can transform a polydispersed aerosol into a monodispersed aerosol with high mass yield. Strong preliminary evidence supports the new mechanism. The goals of this project are to 1) develop a robust computational model that incorporates the new mechanism, which will be general and applicable to many different materials using the plasma parameters and residence time as inputs; 2) develop methods to experimentally control the position of the monodispersed peak; 3) identify scaling parameters that would allow the mass throughput to be increased while maintaining a given monodispersed size distribution; and 4) apply the mechanism to synthesize compound semiconductor nanocrystals containing two or more elements.

该奖项将支持计算和实验研究，以了解低温等离子体中纳米材料合成的机制。低温等离子体（LTPs）是一种自由相互作用的带电粒子和中性粒子的混合物，其高化学反应性为生产新材料提供了巨大的机会。由于通过与ltp的相互作用将材料加工成新结构的理论限制仍然未知，因此也有机会通过实验发现以意想不到的方式改变材料的新工艺。ltp在纳米材料制造中的应用是无处不在的，例如，在生产用于计算机的集成电路或开发先进的储能电池中。因此，纳米颗粒在低温等离子体中的形成和生长的基本知识对于进一步改进先进的制造工艺是必不可少的。本项目将探索一种新的气溶胶机制，这是以前没有考虑过的。该机制允许生产由生产方法目前尚不清楚的材料组成的单分散纳米颗粒。在LTPs中，纳米颗粒可以由于离子轰击而汽化。汽化产生过饱和蒸汽。而过饱和的蒸汽，反过来又凝结回等离子体中的粒子或形成新的团核。这种在等离子体中汽化然后冷凝的过程可以导致单分散的尺寸分布。事实上，这种工艺可以将多分散气溶胶转化为具有高质量产率的单分散气溶胶。强有力的初步证据支持这一新机制。该项目的目标是1)开发一个包含新机制的强大计算模型，该模型将是通用的，适用于许多不同的材料，使用等离子体参数和停留时间作为输入；2)建立实验控制单分散峰位置的方法；3)确定可在保持给定单分散粒度分布的同时增加质量吞吐量的缩放参数；4)应用该机制合成含有两种或两种以上元素的复合半导体纳米晶体。