有机酸在气溶胶多种成核机制中作用机理的理论研究

气溶胶对环境空气质量、大气能见度、人体健康和气候变化等具有重大影响，特别是近年来雾霾污染已成为中国严重的环境问题之一。雾霾问题的实质是气溶胶污染问题，而成核是气溶胶形成的关键步骤。气溶胶的成核是通过氢键、卤键及质子传递等相互作用形成分子团簇的过程。有机酸在大气中广泛存在，在气溶胶常见的成核机制如中性成核、离子感应成核以及碘氧化物成核中都起到至关重要的作用。然而目前由于受仪器限制有机酸参与成核的微观机理尚不清楚，实验和观测结果不统一，严重影响气溶胶的污染控制。本项目拟采用高水平量子化学计算和分子模拟的方法系统地研究有机酸在不同成核机制中的作用，从分子、原子水平上探索其形成的分子团簇的结构信息、能量信息、相互作用机理及平衡常数等，并确定临界核的化学组成及粒径大小。期望通过本项目的研究，为有效控制二次有机气溶胶污染，以及治理大气灰霾污染和环境立法、环境规划，提供强有力的理论依据和科技支撑。

Aerosols have significant impact on ambient air quality, atmospheric visibility, human health and climate change, especially in recent years haze pollution has become one of serious environmental problems in China. The essence of the haze problem is aerosol pollution, and nucleation is the key step in the formation of aerosols. Aerosol nucleation process is the formation of molecular clusters through hydrogen bonding, halogen bonding and proton transfer process. Currently, organic acids are widespread in the atmosphere, and the common nucleation mechanisms of the aerosol play a crucial role in neutral nucleation, ion induced nucleation and iodine oxide nucleation. However, due to the limit of current instrument, the microscopic mechanism of nucleation of organic acid is unclear, and experimental and observational results are not coincident, it seriously affects the aerosol pollution control. This project intends to use high-level quantum chemical calculations and molecular modeling methods to systematically study the role of organic acids in different nucleation mechanisms, obtain structural information, energy information, interaction mechanism and equilibrium constants of the formed molecular clusters at the molecular and atomic level, and determine the chemical composition and particle size of the critical nucleus. We expect that this research can provide a strong theoretical basis and technological support for not only the effective control of secondary organic aerosol pollution and atmospheric haze pollution, but also the environmental legislation and environmental planning.