Abstract Heterogeneous condensation events play an important role in the atmospheric environment and pre-technique for fine particle removal. In present work, superhydrophobic/particle surfaces were prepared and applied to achieve the direct observation of heterogeneous condensation on uniform particle's surface by an environmental scanning electronic microscope (ESEM). It indicates that heterogeneous condensation site on a single particle is randomly distributed. However, when the particles are connected together, heterogeneous condensation always occurs at the interface of particles. It shows that the interface between particles is favorable for nucleation process. This is because the Gibbs free energy barrier of critical cluster formed at the particle interface is smaller than that at other sites. Basing on the experimental and critical free energy calculation results, the evolution of heterogeneous condensation on particles is inferred. It shows that the initial stage and critical supersaturation of heterogeneous condensation on two or more particles are the same.

中文翻译：

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直接观察具有均匀表面的微米颗粒上的异质凝结

摘要 非均相冷凝事件在大气环境和细颗粒物去除前技术中起着重要作用。在目前的工作中，制备并应用超疏水/颗粒表面，以通过环境扫描电子显微镜（ESEM）直接观察均匀颗粒表面的异质凝聚。这表明单个颗粒上的异质凝结点是随机分布的。然而，当粒子连接在一起时，粒子的界面处总会发生异质凝聚。这表明粒子之间的界面有利于成核过程。这是因为在粒子界面形成的临界团簇的吉布斯自由能垒比其他位置小。根据实验和临界自由能计算结果，推断粒子上的非均相凝聚的演化。这表明两个或多个粒子上的非均相凝聚的初始阶段和临界过饱和度是相同的。