From Supersonic Expansions to Atmospheric Particles: Bridging the Gap Between Early Nucleation Stages and Aerosols

CFM Colloquium Series

Aerosols play a key role in physicochemical processes affecting climate change and human health. Understanding the early stages of nucleation is crucial for improving climate models and mitigating aerosol-related impacts. However, uncertainties remain regarding nucleation mechanisms, including the identification of species involved and the evolution of small clusters into aerosol particles.1,2

For years, the Spectroscopy, Spectrometry and Materials Group (GS2M) at the University of the Basque Country (UPV/EHU) has studied the conformational landscape and the intra- and intermolecular interactions governing various molecules in the isolated phase, developing advanced spectroscopic techniques to unravel molecular clustering processes while maintaining precise control of the physical and chemical properties of the systems studied. Whilst Microwave (MW) Spectroscopy resolves molecular energy levels that differ by only a few kHz, providing a very precise structural view, the combination of nanosecond laser pulses with mass spectrometric detection allows the discrimination of larger molecular conformers. These techniques, combined with computational calculations, provide a complete picture of nucleation processes from the smallest clusters to the largest molecular aggregates close to aerosol particles.3,4,5

Building on our previous experience, we now seek to expand our focus to aerosol formation, taking advantage of our knowledge and methodologies to deepen the study of these complex systems. In this talk, we present high-resolution spectroscopy in supersonic expansions as a powerful tool to investigate the nucleation mechanisms of atmospheric species of interest. In addition, we discuss future prospects for the design and construction of an experiment aimed at aerosol generation.

References:

1S.-H. Lee, H. Gordon, H. Yu, K. Lehtipalo, R. Haley, Y. Li and R. Zhang, Journal of Geophysical Research: Atmospheres, 2019, 124, 7098–7146

2J. Elm, J. Kubecka, V. Besel, M. J. Jääskeläinen, R. Halonen, T. Kurten and H. Vehkamäki, Journal of Aerosol Science, 2020, 149, 105621.

3M. Parra-Santamaria, 76th International Symposium on Molecular Spectroscopy, 2023, p. 225.

4Maider Parra-Santamaria, Conference of Young Researchers in Atomic and Molecular Physics (J2IFAM), 2022, p. 225.

5 Iker León, Imanol Usabiaga, Pedro F. Arnaiz, Alberto Lesarri and José A. Fernández, Chem. Eur. J. 2018, 24, 10291 – 10295.