Insight into Acid鈥揃ase Nucleation Experiments by Comparison of the Chemical Composition of Positive, Negative, and Neutral Clusters

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• 作者：Federico Bianchi ; Arnaud P. Praplan ; Nina Sarnela ; Josef Dommen ; Andreas K眉rten ; Ismael K. Ortega ; Siegfried Schobesberger ; Heikki Junninen ; Mario Simon ; Jasmin Tr枚stl ; Tuija Jokinen ; Mikko Sipil盲 ; Alexey Adamov ; Antonio Amorim ; Joao Almeida ; Martin Breitenlechner ; Jonathan Duplissy ; Sebastian Ehrhart ; Richard C. Flagan ; Alessandro Franchin ; Jani Hakala ; Armin Hansel ; Martin Heinritzi ; Juha Kangasluoma ; Helmi Keskinen ; Jaeseok Kim ; Jasper Kirkby ; Ari Laaksonen ; Michael J. Lawler ; Katrianne Lehtipalo ; Markus Leiminger ; Vladimir Makhmutov ; Serge Mathot ; Antti Onnela ; Tuukka Pet盲j盲 ; Francesco Riccobono ; Matti P. Rissanen ; Linda Rondo ; Ant贸nio Tom茅 ; Annele Virtanen ; Yrj枚 Viisanen ; Christina Williamson ; Daniela Wimmer ; Paul M. Winkler ; Penglin Ye ; Joachim Curtius ; Markku Kulmala ; Douglas R. Worsnop ; Neil M. Donahue ; Urs Baltensperger
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：December 2, 2014
• 年：2014
• 卷：48
• 期：23
• 页码：13675-13684
• 全文大小：448K
• ISSN：1520-5851

文摘

We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid鈥揵ase addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster鈥揷luster collision.