Aerosol Optical Tweezers Constrain the Morphology Evolution of Liquid-Liquid Phase-Separated Atmospheric Particles
Aerosol Optical Tweezers Constrain the Morphology Evolution of Liquid-Liquid Phase-Separated Atmospheric Particles
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DOI：
10.1016/j.chempr.2019.10.018
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发表时间：
2020-01-09
期刊：
影响因子：
23.5
通讯作者：
Sullivan, Ryan C.
中科院分区：
文献类型：
--
作者：
Gorkowski, Kyle;Donahue, Neil M.;Sullivan, Ryan C.
大气颗粒物的化学模型对于理解气溶胶颗粒物在大气化学、空气污染、人类健康和气候变化中的作用至关重要。推进这些模型需要新的框架，可以现实地预测关键粒子属性如何演变。我们提出了这样一个框架来预测粒子相分离和形态将占上风，这控制着每个粒子如何与大气相互作用并影响大气。我们研究了α-蒎烯二次有机气溶胶（SOA）与不同的有机相的混合行为，相对湿度是不同的，以确定极性，溶解性，界面张力之间的相互作用，并由此产生的形态。使用气溶胶光镊实验和文献数据的测量，观察到随着大气氧化的增加，形态的一般趋势，从两相部分吞没（其中两相立即进入气相）到两相核壳（其中有机壳隐藏核），最后到单相，均匀形态。
Chemical models of atmospheric particles are vital in understanding the role of aerosol particles in atmospheric chemistry, air pollution, human health, and climate change. Advancing these models requires new frameworks that can realistically predict how critical particle properties evolve. We present such a framework for predicting particle phase separation and which morphology will prevail; this controls how each particle interacts with and affects the atmosphere. We studied the mixing behavior of alpha-pinene secondary organic aerosol (SOA) with different organic phases, as relative humidity was varied to determine the interplay between polarity, miscibility, interfacial tension, and the resulting morphology. Using measurements from aerosol optical tweezers experiments and literature data, a general trend in morphology with increasing atmospheric oxidation was observed, from biphasic partially engulfed (where both phases are immediately accessible to the gas phase) to biphasic core shell (where the organic shell conceals the core) and finally to a single-phase, homogeneous morphology.