Aerosol particles play an important role in atmospheric physical or chemical reactions. Charging of aerosol particles is also widely used in various engineering applications, such as electrical low-pressure impactors and differential mobility analyzers. In this paper, the charging process of nanometer-sized liquid aerosol particles in an atmospheric environment is studied theoretically and experimentally. The traditional charging equation is modified taking the variation of carried charges and the number density of liquid aerosol particles into consideration, due to the coalescence of liquid aerosol particles that brings 100% charge conversion efficiency. By fitting the experimental data under a low discharge voltage, an appropriate combination (r, η) is selected, where r is a specific droplet radius and η is the corresponding equivalent conversion factor of charges. The results from the fitting combination (r, η) are in good agreement with the experimental data and it further demonstrates that the charging evolution of droplets with various radiuses under various voltages can be derived from the existing experimental data under a low voltage. In addition, the concept of a charging time constant τ _0.1 is introduced to describe the charging rate. This paper may provide a reference to reveal and optimize the charging process of liquid aerosol particles and broaden the engineering applications for the charging of aerosol particles.

气溶胶颗粒在大气物理或化学反应中起重要作用。气溶胶颗粒的装料还广泛用于各种工程应用中，例如低压电动撞击器和差动迁移率分析仪。本文从理论和实验上研究了大气环境中纳米级气溶胶颗粒的充电过程。修改了传统的充电公式，考虑到携带的电荷的变化和液态气雾剂颗粒的数量密度，这归因于液态气雾剂颗粒的聚结带来了100％的电荷转换效率。由低放电电压，适当组合（下拟合实验数据R，η）被选择，其中ř是特定的液滴半径，η是相应的电荷等效转换系数。拟合组合（r，η）的结果与实验数据吻合良好，进一步证明了在低压下，各种半径的液滴在不同电压下的带电演化可以从现有的实验数据中推导出来。此外，充电时间常数的概念τ _0.1被引入来描述充电率。本文可以为揭示和优化液态气溶胶颗粒的充电过程提供参考，并为气溶胶颗粒的充电拓展工程应用。