Neutral molecular cluster formation of sulfuric acid–dimethylamine observed in real time under atmospheric conditions

• DOI: 10.1073/pnas.1404853111
• Publication Date: 2014-10-07T02:54:30Z
• Authors: Andreas Kürten; Tuija Jokinen; Mario Simon; Mikko Sipilä; Nina Sarnela; Heikki Junninen; Alexey Adamov; João Almeida; Antonio Amorim; Federico Bianchi; Martin Breitenlec...; Josef Dommen; Neil M. Donahue; Jonathan Duplissy; Sebastian Ehrhart; Richard C. Flagan; Alessandro Franchin; Jani Hakala; Armin Hansel; Martin Heinritzi; Manuel Hutterli; Juha Kangasluoma; Jasper Kirkby; Ari Laaksonen; Katrianne Lehtipalo; Markus Leiminger; Vladimir Makhmutov; Serge Mathot; Antti Onnela; Tuukka Petäjä; Arnaud P. Praplan; Francesco Riccobono; Matti P. Rissanen; Linda Rondo; Siegfried Schobes...; John H. Seinfeld; Gerhard Steiner; António Tomé; Jasmin Tröstl; Paul M. Winkler; Christina Williamson; Daniela Wimmer; Penglin Ye; Urs Baltensperger; Kenneth S. Carslaw; Markku Kulmala; Douglas R. Worsnop; Joachim Curtius
• Keywords: atmospheric chemistry; Atmospheric chemistry; 550; aerosol particles; Atmospheric nucleation; FOS: Physical sciences; 103039 Aerosol physics; 01 natural sciences; ORGANIC VAPORS; Physics - Chemical Physics; PARTICLE FORMATION; WATER; RATES; 103039 Aerosolphysik; mass spectrometry; 0105 earth and related environmental sciences; Chemical Physics (physics.chem-ph); AMMONIA; NUCLEI; Mass spectrometry; AMINES; Aerosol particles; atmospheric nucleation; Physical sciences; Physics - Atmospheric and Oceanic Physics; 13. Climate action; 103037 Environmental physics; Atmospheric and Oceanic Physics (physics.ao-ph); GROWTH; AEROSOL NUCLEATION; CONTRIBUTE; 103037 Umweltphysik

Significance A significant fraction of atmospheric aerosols is formed from the condensation of low-volatility vapors. These newly formed particles can grow, become seeds for cloud particles, and influence climate. New particle formation in the planetary boundary layer generally proceeds via the neutral channel. However, unambiguous identification of neutral nucleating clusters has so far not been possible under atmospherically relevant conditions. We explored the system of sulfuric acid, water, and dimethylamine in a well-controlled laboratory experiment and measured the time-resolved concentrations of neutral clusters. Clusters containing up to 14 sulfuric acid and 16 dimethylamine molecules were observed. Our results demonstrate that a cluster containing as few as two sulfuric acid and one or two dimethylamine molecules is already stable against evaporation.