RUI: Kinetics and Products of Hydroxyl Radical (OH) and Chlorine (Cl) Reactions with High Molecular Weight Organic Aerosol Precursor Compounds

对C8-C15高分子量有机气溶胶前体化合物（OAPCs）与大气氧化剂的相互作用进行实验研究，有助于解决大气有机气溶胶化学问题。本项目目的是利用相对速率/放电流量/质谱（RR/DF/MS）技术获取高分子量OAPCs与羟基自由基（OH）和氯自由基（Cl）在220-300 K下反应的速率常数和中间产物信息。这一目标将通过以下一系列活动来实现：1)确定在室温下，在低压和湍流条件下，OH和Cl与3至6个高MW OAPCs反应的速率系数。高分子量OAPCs的主要选择包括正癸烷、正十一烷、正十二烷、十二环己烷、十二环己烷、辛烷、壬烷、癸烷、辛烷酸、壬烷酸、蒎烯、蒽和萘。2)确定了在对流层温度范围（220-300 K）下，OH和Cl与选定的高MW OAPCs反应的速率常数。如果高MW OAPCs在流动反应器上的吸附对动力学结果有显著影响，则在湍流条件下测量速率常数。否则，将在低压条件下确定速率常数作为温度的函数。3)所研究反应的水和盐酸产物的鉴定和定量，如果反应在220-300 K下有多个途径，则确定分支比。从拟议的研究中获得的结果将深入了解大气有机气溶胶的形成、生长和氧化，并提高目前对高MW OAPCs的自然和人为排放对空气质量的影响的理解。从该项目获得的动力学和产品数据将为现有的涉及有机气溶胶的大气模型数据库增加重要的新输入。这个项目的广泛影响将主要是对加州州立大学富勒顿分校（CSUF）的研究环境产生重大的积极影响，这是一个以本科生为主的机构。该项目将为CSUF培养高素质的研究人员和科学家。参与该项目的研究生和本科生将被介绍到大气化学的前沿，并将面临解决研究过程中提出的环境和科学问题的挑战。他们还将接触和学习各种科学方法和技术，包括操作和维护质谱仪、高真空系统、微波放电装置和湍流，以及动力学和产品数据的获取和分析。最后，他们将参加国内和国际会议，展示他们的成果，并在同行评审的科学期刊上发表他们的成果。本研究的一个教育目标是为大三和大四的本科生提供机会，特别是那些代表性不足的群体（少数民族，女性），有切实的研究经验，以培养他们对大气和环境化学的兴趣。

Experimental investigations of the interactions between C8-C15 high molecular weight (MW) organic aerosol precursor compounds (OAPCs) and atmospheric oxidants will be conducted to help address issues concerning atmospheric organic aerosol chemistry. The objective of this project is to acquire rate constants and intermediate/product information at 220-300 K for reactions of Hydroxyl Radical (OH) and Chlorine (Cl) radicals with high MW OAPCs using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique. This objective will be achieved through the following set of activities:1) Determination of rate coefficients for the reactions of OH and Cl with three to six high MW OAPCs under both low pressure and turbulent flow conditions at room temperature. Primary choices of high MW OAPCs include n-decane, n-undecane, n-dodecane, dodecylcyclohexane, decylcyclohexane, octanal, nonanal, decanal, octanoic acid, nonanoic acid, pinenes, anthracene, and naphthalene.2) Determination of rate constants for the reactions of OH and Cl with selected high MW OAPCs at temperature ranges representative of the troposphere (220-300 K). If the adsorption of high MW OAPCs onto the flow reactor significantly affects the kinetic results, the rate constants will be measured under turbulent flow conditions. Otherwise rate constants as a function of temperature will be determined under low-pressure conditions.3) Identification and quantification of the water and hydrocholoric acid products for the reactions under investigation, and determination of the branching ratio if the reaction has more than one pathway at 220-300 K.Results obtained from the proposed research will provide insight on the formation, growth, and oxidation of atmospheric organic aerosols, and improve current understanding of the impact of natural and anthropogenic emissions of high MW OAPCs on air quality. The kinetic and product data obtained from this project will add important new inputs to the existing database for atmospheric modeling involving organic aerosols.The broader impacts of this project will be primarily the significant positive impact on the research environment at California State University Fullerton (CSUF), which is a predominantly undergraduate institution. The project will lead to the training of high quality researchers and scientists at CSUF. Both graduate and undergraduate students involved in this project will be introduced to the frontiers of atmospheric chemistry and will be challenged to address both environmental and scientific questions raised during the research. They will also be exposed to and learn a variety of scientific methods and techniques, including operation and maintenance of a mass spectrometer, high vacuum systems, microwave discharge devices, and turbulent flows, plus kinetic and product data acquisition and analysis. Finally, they will participate in national and international meetings to present their results, and publish their results in peer-reviewed scientific journals.One educational goal of this research is to provide opportunities for junior and senior undergraduate students, especially those of underrepresented groups (minorities, females), to have tangible research experience in order to foster their interests in atmospheric and environmental chemistry.