ICARUS Chamber Experiment: Nguyen Group_20190702_ALPHA-PINENE/OZONE/10102-44-0/hydrogen peroxide_Nitrate radical_Ammonium sulfate_2.8ugm3_seeds

Goals: To quantify the nitrooxy-hydroperoxide yield and the SOA yield from nighttime RO2+HO2-dominated NO3-initiated chemistry of a-pinene by adding H2O2 + ozone + NO2 to the chamber. Part of a series of varying initial seed particle surface area to see how that affects SOA formation.Summary: H2O2, NO2, and O3 were injected in the chamber and allowed to equilibrate, forming NO3 (and some N2O5) and probably HO2. Ammonium sulfate seed particles were injected. Then a-pinene was injected and decayed by simultaneous reaction with ozone and NO3. Gas phase was monitored by CF3O- CIMS and particle formation by SMPS. A filter was collected for later offline analysis.Organization: Nguyen Group Lab Affiliation: UC Davis Chamber: Tran's big bag of airExperiment Category: Gas phase chemical reaction, Aerosol formation Oxidant: Nitrate radical Reactants: ALPHA-PINENE, OZONE, 10102-44-0, hydrogen peroxide Reaction Type: Dark oxidation Relative Humidity: 5 Temperature: 22 Seed Name: Ammonium sulfate Pressure: 755 Torr

研究目标：通过向反应腔室中加入过氧化氢（H₂O₂）、臭氧（O₃）与二氧化氮（NO₂），量化由硝酸根自由基（NO₃）引发的、夜间以RO₂+HO₂为主导的α-蒎烯（a-pinene）化学反应所生成的硝基氢过氧化物产率与二次有机气溶胶（Secondary Organic Aerosol, SOA）产率。本实验属于一系列改变初始种子颗粒表面积的研究子集，旨在揭示该参数对二次有机气溶胶生成过程的调控效应。
实验流程：首先向腔室注入过氧化氢、二氧化氮与臭氧并使其达到平衡，生成硝酸根自由基与少量五氧化二氮（N₂O₅），同时大概率生成氢过氧自由基（HO₂）；随后注入硫酸铵种子颗粒；再注入α-蒎烯，其将与臭氧及硝酸根自由基同时发生反应并逐渐降解。气相组分采用CF₃O⁻化学电离质谱（CF3O- CIMS）进行在线监测，颗粒成核与生长过程则通过扫描迁移率粒子粒径谱仪（SMPS）实时测定。此外还采集了滤膜样品，用于后续离线分析。
依托单位：阮氏课题组实验室（Nguyen Group Lab），隶属于加州大学戴维斯分校（UC Davis）
实验腔室：特兰大气袋装置（Tran's big bag of air）
实验类别：气相化学反应、气溶胶生成
氧化剂：硝酸根自由基
反应物：α-蒎烯、臭氧、CAS编号10102-44-0、过氧化氢
反应类型：暗氧化反应
相对湿度：5%
温度：22℃
种子颗粒名称：硫酸铵
压力：755托（Torr）