含表面活性成分气溶胶颗粒吸湿生长动力学机理研究

吸湿生长通过改变大气气溶胶颗粒的物理化学性质而影响其环境和健康效应，表面活性成分对该非稳态过程有重要影响，然而当前对其认识还很缺乏。本项目拟采用分子动力学模拟、多相流动力学理论建模和实验研究相结合的方法探究含表面活性成分气溶胶颗粒吸湿生长动力学机理。基于分子动力学模拟定量获取描述颗粒吸湿生长过程中结构界面特性和热质传递过程的微观参数的演变机制；基于分层思想构建气溶胶吸湿生长非稳态过程预测模型，详细考虑水蒸气扩散和可逆吸收、颗粒表面至核心热质传递、表面活性成分分配、组分分子间相互作用对分子活度和扩散动力学的影响等，且微观参数采用分子动力学模拟结果；基于实验探究单个气溶胶颗粒在吸湿生长过程中形貌结构和粒径的变化速率，验证并完善非稳态理论模型。最终基于模型获得吸湿生长机理性认识。项目旨在解决含表面活性成分气溶胶颗粒吸湿生长过程中的复杂热质传递问题，并为大气气溶胶污染的预测和治理提供科学依据。

Hygroscopic growth affects the environmental and health effects of atmospheric aerosol particles by changing their physicochemical properties. Surface active ingredients have an important influence on this non-steady state process. However, the current understanding of this issue is insufficient. In this proposal, molecular dynamics simulation, theoretical modeling of multiphase flow dynamics and experimental investigation would be conducted to deeply explore the kinetic mechanism in hygroscopic growth of aerosol particles containing surface active ingredients. Molecular dynamic method would be employed to quantitatively reveal the evolution mechanism of microscopic parameters descibing the structural and interfacal properties of aerosol particles and the heat and mass transfer processes during their hygroscopic growth. The prediction model of the aerosol hygroscopic growth unsteady process would be established based on the layering concept, in which the water vapor diffusion and reversible absorption, heat and mass transfer between the surface and core of particle, partitioning of the surface active ingredients, effects of intermolecular interaction on molecular activity and diffusion dynamics, etc. are considered in detail. An experiment system would be designed to investigate the morphology and size change rate of the single particle during its hygroscopic growth. The experimental outcomes would be used to verify and improve the prediction model of the unsteady process. Finally, the mechanism understanding of the hygroscopic growth will be obtained based on the prediction model. This project aims to solve the complex heat and mass transfer problems in the hygroscopic growth process of aerosol particles containing surface active ingredients, and provide scientific basis for the prediction and management of atmospheric aerosol pollution.