Perfluoropropionic Acid-Driven Nucleation of Atmospheric Molecules under Ambient Conditions

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Computational Chemistry

Background:

• Secondary organic aerosols (SOAs) impact atmospheric quality and human health.
• Persistent organic pollutants (POPs), particularly perfluorinated compounds (PFCAs), are of growing concern due to their environmental persistence and adverse health effects.
• Understanding the role of specific PFCAs, like perfluoropropionic acid (PFPA), in atmospheric processes is crucial.

Purpose of the Study:

• To investigate the electrostatic interactions between perfluoropropionic acid (PFPA) and key atmospheric molecules using high-level density functional theory.
• To analyze the structural, energetic, electrical, and spectroscopic properties of binary PFPA-atmospheric molecule clusters.
• To assess the potential role of PFPA in atmospheric nucleation and new particle formation.

Main Methods:

• High-level density functional theory (DFT) calculations.
• Systematic quantum chemical analysis of binary clusters.
• Evaluation of structural, energetic, electrical, and spectroscopic properties, including Rayleigh activities.

Main Results:

• PFPA forms highly stable hydrogen-bonded binary clusters with atmospheric nucleation precursors such as sulfuric acid (H2SO4) and methanesulfonic acid (MSA).
• The formation of these clusters leads to a significant increase in Rayleigh scattering activities.
• Analysis of binding energies and free-energy changes indicates PFPA's potential involvement in atmospheric nucleation processes.

Conclusions:

• Perfluoropropionic acid (PFPA) can effectively participate in the initial stages of atmospheric nucleation.
• PFPA-containing clusters contribute to new particle formation in the atmosphere.
• These findings highlight the importance of considering PFPA in atmospheric aerosol research and pollution assessment.