Constraining the Degradation Pathways of Siloxanes in the Atmosphere

限制硅氧烷在大气中的降解途径

• 批准号: 1808606
• 负责人: Eleanor Browne
• 金额: $ 34.13万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1808606&HistoricalAwards=false
• 关键词: Constraining; Degradation; Pathways; Siloxanes; Atmosphere

This award from the Environmental Chemical Sciences Program in the Division of Chemistry and the Atmospheric Chemistry Program in the Division of Atmospheric and Geospace Sciences supports Professor Eleanor Browne and her graduate and undergraduate students. They study the atmospheric degradation processes of the organosilicon compounds known as siloxanes. Siloxanes are high-production compounds manufactured for a variety of uses, including as components of adhesives, coatings, and personal care products. The siloxanes can be detected in environmental samples worldwide including in remote Arctic regions. Due to the environmental persistence of these compounds and concerns over their toxicity to aquatic organisms, the environmental chemistry of siloxanes is an emerging area of interest. In the environment, siloxanes preferentially partition to the atmosphere where they undergo chemical reactions to form new products. These products may have a different fate than the original compound. This project improves the understanding of the timescale and products of the atmospheric degradation of siloxanes and provides the data necessary to evaluate their environmental fate. Through this project, graduate, undergraduate, and high-school students receive training in atmospheric chemistry techniques and analytical instrumentation. Students also develop scientific communication skills by creating videos describing the work. Results are incorporated into undergraduate educational materials. This project uses laboratory experiments to investigate the multigenerational atmospheric chemistry of siloxanes. The reaction rates of common linear and cyclic siloxanes with the hydroxyl radical and chlorine atom are measured to understand the lifetime of the compounds. The work investigates the mechanism and products of the gas-phase oxidation of siloxanes under conditions approximating urban, rural, and remote atmospheres. Experiments probing the uptake of oxidation products into particles explore the interactions between gas-phase siloxanes and submicron particles. Both reactants and products are measured in real time with chemical ionization mass spectrometry.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项获得了化学和大气化学科学系的环境化学科学计划，大气和地理水平科学系为埃莉诺·布朗（Eleanor Browne）教授及其毕业生和本科生提供支持。他们研究了有机硅化合物的大气降解过程，称为硅氧烷。 Siloxanes是用于多种用途的高生产化合物，包括作为粘合剂，涂料和个人护理产品的组成部分。在全球环境样品中，包括在偏远北极地区，可以检测到硅氧烷。由于这些化合物的环境持久性以及对它们对水生生物的毒性的关注，因此，硅氧烷的环境化学是一个新兴领域。在环境中，硅氧烷优先分配到会产生化学反应以形成新产品的大气中。这些产品的命运可能与原始化合物不同。该项目提高了对Siloxanes大气降解的时间表和产物的理解，并提供了评估其环境命运所需的数据。通过这个项目，毕业生，本科和高中生接受大气化学技术和分析仪器的培训。学生还通过创建描述作品的视频来发展科学的沟通技巧。结果被纳入本科教育材料中。 该项目使用实验室实验研究硅氧烷的多代大气化学。测量了常见线性和环状硅氧烷与羟基和氯原子的反应速率，以了解化合物的寿命。这项工作研究了近似城市，农村和偏远大气的条件下的硅氧烷气相氧化的机制和产物。探测氧化产物摄入颗粒的实验探索了气相西子和亚微米颗粒之间的相互作用。反应物和产品都是通过化学电离质谱实时测量的。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响标准，被认为值得通过评估来获得支持。

项目成果

Atmospheric Chemistry of Volatile Methyl Siloxanes: Kinetics and Products of Oxidation by OH Radicals and Cl Atoms

• DOI: 10.1021/acs.est.0c01368
• 发表时间: 2020-05-19
• 期刊: ENVIRONMENTAL SCIENCE & TECHNOLOGY
• 影响因子: 11.4
• 作者: Alton, Mitchell W.;Browne, Eleanor C.
• 通讯作者: Browne, Eleanor C.

Volatile Methyl Siloxane Atmospheric Oxidation Mechanism from a Theoretical Perspective─How is the Siloxanol Formed?

理论视角下的挥发性甲基硅氧烷大气氧化机理——硅氧烷醇是如何形成的？

• DOI: 10.1021/acs.jpca.3c06287
• 发表时间: 2023
• 期刊: The Journal of Physical Chemistry A
• 作者: Alton, Mitchell W.;Johnson, Virginia L.;Sharma, Sandeep;Browne, Eleanor C.
• 通讯作者: Browne, Eleanor C.