Size-dependent depositional loss of inorganic, organic, and mixed composition particles to Teflon chamber walls under various environmental and chemical conditions
Size-dependent depositional loss of inorganic, organic, and mixed composition particles to Teflon chamber walls under various environmental and chemical conditions
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DOI：
10.1080/02786826.2023.2298219
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发表时间：
2024-01
影响因子：
5.2
通讯作者：
Adrianne Nakagawa;K. Bates;Tran B. Nguyen
中科院分区：
文献类型：
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作者：
Adrianne Nakagawa;K. Bates;Tran B. Nguyen
摘要在粒子形成和老化的实验研究中，聚四氟乙烯室壁的一阶粒子损失修正是不确定性的重要来源。粒度分布和环境因素显着影响壁损失校正，因此，重要的是要表征尺寸依赖的颗粒损失的档案下无数的实验条件下，可能会改变沉积速率。这项工作研究了无机（硫酸铵，AS），有机（山梨糖醇，C6 H14 O 6），和混合组合物（AS +山梨糖醇，1：1摩尔）颗粒在不同的室温度（20-40 °C），相对湿度（RH，<10-80%），照明（黑暗与100%室光），颗粒水（结晶与潮解与亚稳态），和室使用历史条件（清洁室与以下化学实验）下的铁氟龙室的尺寸依赖性损失系数。结果发现，温度和光照对所有颗粒的损失率的影响可忽略不计，而RH、颗粒水和灭菌室使用历史在所有测试条件下均具有重大影响。颗粒壁损失率在潮湿条件下比干燥条件下更高，潮解颗粒比干燥颗粒在类似的RH。尽管推荐了腔室冲洗方案，但在壁损失实验前一天将酸性物质引入腔室壁的化学条件导致壁损失率曲线的不确定性高达50%。这些数据表明，敏感的OA形成或老化实验可以考虑从目标实验中获得同一天的壁损失曲线。否则，颗粒壁损失的尺寸相关校正应考虑颗粒组成，颗粒水，RH，壁使用历史，并可能照明条件。版权所有© 2024美国气溶胶研究协会
Abstract Corrections for first-order particle losses to Teflon chamber walls are important sources of uncertainty in experimental studies of particle formation and aging. Particle size distributions and environmental factors significantly influence wall loss corrections; thus, it is important to characterize size-dependent particle loss profiles under myriad experimental conditions that may alter deposition rates. This work investigated size-dependent loss coefficients of inorganic (ammonium sulfate, AS), organic (sorbitol, C6H14O6), and mixed composition (AS + sorbitol, 1:1 by mole) particles to a Teflon chamber under varying chamber temperature (20–40 °C), relative humidity (RH, <10–80%), illumination (dark vs. 100% chamber lights), particle water (crystalline vs. deliquesced vs. metastable), and chamber usage history conditions (clean chamber vs. following chemical experiments). It was found that temperature and lights had negligible to minor effects on loss rates for all particles, while RH, particle water, and chamber usage history each had major effects under all tested conditions. Particle wall loss rates were higher under humid than dry conditions, and higher for deliquesced particles than for dry particles at similar RH. Chemical conditions that introduced acidic species to chamber walls the day prior to a wall loss experiment were responsible for uncertainties of up to ∼50% in wall loss rate profiles, despite recommended chamber flushing regimens. These data suggest that sensitive OA formation or aging experiments may consider obtaining same-day wall loss profiles from the target experiment. Otherwise, size-dependent corrections for particle wall loss should consider particle composition, particle water, RH, wall usage history, and possibly illumination conditions. Copyright © 2024 American Association for Aerosol Research