The Impacts of Phase Separation and Particle Shape on Aerosol Optical Properties Measured using Single Particle Cavity Ring-Down Spectroscopy

相分离和颗粒形状对使用单颗粒腔衰荡光谱测量的气溶胶光学性质的影响

• 批准号: 2886474
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2886474
• 关键词: Impacts; Phase; Separation; Particle; Shape

Atmospheric aerosol particles regulate Earth's climate, yet their description represents one of the largest uncertainties in climate models. In particular, the interactions of light with atmospheric particles of varying shape and internal structure are understood poorly. The optical properties of morphologically complex aerosols are also important in understanding disease transmission. For example, pathogen-containing droplets emitted during human exhalation are thought to exhibit multiple phases,1,2 and understanding their optical properties is central to designing sterilisation devices that could improve public health. Liquid droplets adopt spherical shapes for which the calculation of optical properties are straightforward. However,solid particles (such as those formed through drying of aqueous droplets that contain dissolved salts) adopt a wide range of shapes that scatter and absorb light in complex ways. Particles also adopt a wide range of internal structures. For example, an aqueous particle comprised of a mixture of organic and inorganic species may undergo liquid-liquid phase separation (LLPS), the optical properties for which will differ from those expected of a homogeneous particle.Few studies have measured the impacts of shape or LLPS on aerosol optical properties with sufficient accuracy or sensitivity to challenge optical models thatdescribe morphologically complex particles.

大气气溶胶颗粒调节地球气候，但它们的描述代表了气候模型中最大的不确定性之一。特别是，人们对光与不同形状和内部结构的大气颗粒之间的相互作用知之甚少。形态复杂的气溶胶的光学特性对于理解疾病传播也很重要。例如，人类呼气过程中排出的含有病原体的液滴被认为表现出多个阶段1,2，了解其光学特性对于设计可改善公共健康的灭菌设备至关重要。液滴采用球形，其光学特性的计算很简单。然而，固体颗粒（例如通过干燥含有溶解盐的水滴而形成的颗粒）具有多种形状，以复杂的方式散射和吸收光。粒子还采用多种内部结构。例如，由有机和无机物质的混合物组成的水性颗粒可能会经历液-液相分离 (LLPS)，其光学性质将不同于均质颗粒的预期光学性质。很少有研究测量形状或形状的影响。 LLPS 对气溶胶光学特性的分析具有足够的精度或灵敏度，足以挑战描述形态复杂颗粒的光学模型。