Effects of Molecular-Level Compositional Variability in Organic Aerosol on Phase State and Thermodynamic Mixing Behavior
Effects of Molecular-Level Compositional Variability in Organic Aerosol on Phase State and Thermodynamic Mixing Behavior
复制标题
DOI：
10.1021/acs.est.9b02664
复制
发表时间：
2019-11-19
影响因子：
11.4
通讯作者：
Gentner, Drew R.
中科院分区：
文献类型：
--
作者：
Ditto, Jenna C.;Joo, Taekyu;Gentner, Drew R.
有机气溶胶分子水平的组成和结构影响其化学/物理性质、转化和影响。在这里，我们使用的功能化OA从三个不同的领域网站的分子水平的化学组成，以评估OA相态和热力学混合的易变性的分子水平的组成的影响。对于这些环境站点，模拟的气溶胶相态范围从液体到半固体。所观察到的OA组合物的可变性对所得的相态有一定影响，但其他因素如无机离子的存在、气溶胶液态水以及与水的内部与外部混合是这些颗粒是否以液体、半固体或固体形式存在的决定因素。有机分子组成对相分离（相对于充分混合）体系的相态决定起着更重要的作用。类似地，尽管观察到OA组成差异，但OA样品与气溶胶液态水、异戊二烯氧化产物或单萜氧化产物的热力学混合相容性在每个活动中保持相当一致。过滤取样的OA和异戊二烯或单萜氧化产物的混合通常在两个季节都是有利的，而与水混合通常是不利的。
The molecular-level composition and structure of organic aerosol (OA) affect its chemical/physical properties, transformations, and impacts. Here, we use the molecular-level chemical composition of functionalized OA from three diverse field sites to evaluate the effect of molecular-level compositional variability on OA phase state and thermodynamic mixing favorability. For these ambient sites, modeled aerosol phase state ranges from liquid to semisolid. The observed variability in OA composition has some effect on resulting phase state, but other factors like the presence of inorganic ions, aerosol liquid water, and internal versus external mixing with water are determining factors in whether these particles exist as liquids, semisolids, or solids. Organic molecular composition plays a more important role in determining phase state for phase-separated (verus well-mixed) systems. Similarly, despite the observed OA compositional differences, the thermodynamic mixing favorability for OA samples with aerosol liquid water, isoprene oxidation products, or monoterpene oxidation products remains fairly consistent within each campaign. Mixing of filter-sampled OA and isoprene or monoterpene oxidation products is often favorable in both seasons, while mixing with water is generally unfavorable.