From volatile organic compounds to aerosols: quantum-level insights into humidity-induced cluster formation in atmospheres

Abstract

New particle formation (NPF) is a key factor in producing the aerosol populations in the atmosphere. This has enormous effects on controlling the climate, improving air quality, and protecting human health. Volatile organic compounds (VOCs) are a significant cause of NPF because they help prenucleation clusters form, which are the building blocks of aerosol particles. We employed density functional theory (DFT) to investigate the structure and thermodynamics of molecular clusters composed of acetic acid, acetone, acetaldehyde, and formaldehyde in the presence of ammonia and varying amounts of water molecules (n = 0–30). Our study examines binding energies, enthalpies, and free energies that are BSSE-corrected across a range of atmospheric temperatures (T) and pressures (P), reflecting the changes in the real-world environment. We also look at Rayleigh scattering levels , which shows a steady rise with cluster hydration. The results show that different VOC systems interact and cluster in distinct ways, providing more information about their roles in the atmosphere. This study may offer fresh insights into how different VOCs function in specific scenarios, which is necessary to comprehend new particle formation events in polluted areas.