Webinar title: Microdroplet Chemistry and Environmental Implication

Speaker: Liwu Zhang

Webinar time: 14:00, Dec 22, 2023 (Friday)

Venue: Room 231, New Environmental Building; Tencent Meeting 656-744-632, Password 231222

Inviter: Xu Haomiao, Yan Naiqiang

Abstract：

Microdroplets are widely prevalent in nature and, due to their abundant gas-liquid interfaces, possess physicochemical properties that are significantly different from those of bulk solutions. This report will focus on discussing the unique physical and chemical properties of microdroplets, their role in atmospheric pollution, and their applications in pollution control. We have found that the rate of chemical reactions within microdroplets is significantly increased compared to bulk phases. Atmospheric aerosol microdroplets act as microreactors, where pH plays a crucial role in regulating these processes. The problem of spatial distribution of pH and chemical species within atmospheric microdroplets has not yet been resolved. We have proposed a non-invasive technique using stimulated Raman scattering microscopy to visualize the three-dimensional pH distribution within microdroplets of various sizes. Additionally, we have discovered that reducing the diameter of microdroplets can significantly enhance the rate of photochemical reactions, attributed to the unique chemical mechanisms at the gas-liquid interface, revealing the importance of this interface in promoting photochemical reactions. This study provides new perspectives and a deeper understanding of microdroplet chemistry and its environmental significance.

About the speaker：

    张立武，复旦大学环境科学与工程系教授，博士生导师，副系主任。2009年博士毕业于清华大学化学系，2009-2012年在德国汉诺威大学从事博士后研究（洪堡学者），2012-2014年在剑桥大学物理系从事博士后研究（欧盟玛丽居里学者）。主要从事环境颗粒物污染领域的研究。迄今已在PNAS、Angew、EST等著名期刊发表学术论文140余篇，他人引用10000余次。入选国家海外高层次人才引进计划，主持国家重点研发计划国际合作重点专项等。担任英国皇家化学会期刊Environ Sci: Adv副主编。曾获教育部自然科学一等奖（第四）、中国化学会青年环境化学奖、德国洪堡学者等奖励。