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 α-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.

大气颗粒的化学模型对于理解气溶胶颗粒在大气化学，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，这些框架可以现实地预测关键粒子属性的演化方式。我们提出了一种预测颗粒相分离以及哪种形态将占主导的框架。这样可以控制每个粒子与大气的相互作用和影响方式。我们研究了α-pine烯次生有机气溶胶（SOA）与不同有机相的混合行为，因为相对湿度发生了变化，从而确定了极性，可混溶性，界面张力以及所形成的形态之间的相互作用。利用气溶胶光镊实验的测量结果和文献数据，