Laser-Based Diagnostics for Aerosolized Nanoparticles

基于激光的雾化纳米颗粒诊断

• 批准号: RGPIN-2018-03756
• 负责人: Daun, Kyle
• 金额: $ 9.32万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760415
• 关键词: Laser; Based; Diagnostics; Aerosolized; Nanoparticles

The unique properties of nanoparticles place them prominently at the frontiers of material science. Metal nanoparticles improve the performance solar photovoltaics, for example, while graphitic nanoparticles enable smaller, lighter, and longer-lasting batteries. Since nanoparticle functionality depends strongly on size and shape, new tools that measure these attributes are needed to control bulk nanoparticle production, and to understand their nucleation and growth. At the same time, growing attention focuses on how nanoparticles adversely affect human health and the environment, also in ways that depend strongly on size and morphology. Scientists and engineers increasingly turn to laser-induced incandescence (LII) and multiangle elastic light scattering (MAELS) to characterize synthetic nanoparticles. Nevertheless, significant issues remain with both techniques. LII researchers have derived increasingly-elaborate measurement models for interpreting data without considering how model complexity impacts the reliability of LII-derived estimates, while several commonly-observed spectral features in LII data elude physical interpretation altogether. In the case of MAELS, small errors in the light scattering model are amplified by data inversion into large biases in recovered parameters. These deficiencies limit the reliability of nanoparticle-related quantities derived from these diagnostics.The proposed research program will address these shortcomings by improving the LII and MAELS measurement models, with the long-term goal of developing reliable laser-based nanoparticle diagnostics. Research will commence with a theoretical and experimental investigation of the LII spectroscopic submodel, focusing on a microplasma that may form around the nanoparticle during laser excitation. In parallel, the applicant's team will use Bayesian techniques to derive robust LII and MAELS measurement models for metal nanoparticles, which will then be extended to the more complex case of soot. Finally, these algorithms will be incorporated into a combined LII-MAELS instrument that simultaneously measures primary particle diameter, volume fraction, radius-of-gyration, and fractal dimension of aerosolized nanoaggregates.The metrology techniques developed through this research will be used by Canada's emerging nanotechnology industry to develop new products and materials, and help safeguard Canada's environment and the health of Canadians. More fundamentally, this research will improve our understanding of light-nanoparticle interactions, and provide a way to estimate thermophysical properties under extreme temperatures inaccessible to other measurement modalities. Finally, this research will equip nine HQP with skills in experimentation, theoretical analysis, and numerical simulation, preparing them for careers in both industry and academia.

纳米颗粒的独特特性将它们在材料科学的边界占据着重要性。例如，金属纳米颗粒改善了性能太阳能光伏，而石墨纳米颗粒可以实现较小，更轻且持久的电池。由于纳米颗粒功能在很大程度上取决于尺寸和形状，因此需要测量这些属性的新工具以控制散装纳米颗粒的产生，并了解它们的成核和生长。同时，越来越多的关注集中在纳米颗粒上如何对人类健康和环境产生不利影响，这也很大程度上取决于大小和形态。 科学家和工程师越来越多地转向激光诱导的白炽灯（LII）和多安弹性光散射（Maels）来表征合成纳米颗粒。然而，这两种技术仍然存在重大问题。 LII的研究人员已经得出了越来越大的测量模型来解释数据，而不考虑模型复杂性如何影响LII衍生估计的可靠性，而LII数据中的几种通常具有普遍观察到的光谱特征则完全忽略了物理解释。对于运动，光散射模型中的小误差通过数据反转扩大到回收参数中的巨大偏见。这些缺陷限制了从这些诊断中得出的纳米颗粒相关数量的可靠性。拟议的研究计划将通过改善LII和梅尔斯测量模型来解决这些缺点，其长期目标是开发可靠的基于激光的纳米粒子诊断。研究将从对LII光谱子模型的理论和实验研究开始，重点是在激光激发期间可能在纳米颗粒周围形成的微质量。同时，申请人的团队将使用贝叶斯技术来得出稳健的LII和MALES纳米颗粒的测量模型，然后将其扩展到更为复杂的烟灰情况。 Finally, these algorithms will be incorporated into a combined LII-MAELS instrument that simultaneously measures primary particle diameter, volume fraction, radius-of-gyration, and fractal dimension of aerosolized nanoaggregates.The metrology techniques developed through this research will be used by Canada's emerging nanotechnology industry to develop new products and materials, and help safeguard Canada's environment and the health of Canadians. 从根本上讲，这项研究将提高我们对轻纳米颗粒相互作用的理解，并提供一种在极端温度下估算其他测量方式无法获得的热物理特性的方法。最后，这项研究将为9个HQP提供实验，理论分析和数值模拟的技能，为行业和学术界的职业做好准备。