scholarly journals Enhancing Potential of Trimethylamine Oxide on Atmospheric Particle Formation

Atmosphere ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 35 ◽  
Author(s):  
Nanna Myllys ◽  
Tuomo Ponkkonen ◽  
Sabrina Chee ◽  
James Smith
Keyword(s):  
Cluster Formation ◽  
Particle Formation ◽  
Formation Mechanisms ◽  
Atmospheric Particle ◽  
Dipole Interactions ◽  
Trimethylamine Oxide ◽  
Quantum Chemical Methods ◽  
Low Concentrations ◽  
Stable Clusters ◽  
Level Cluster

The role of an oxidation product of trimethylamine, trimethylamine oxide, in atmospheric particle formation is studied using quantum chemical methods and cluster formation simulations. Molecular-level cluster formation mechanisms are resolved, and theoretical results on particle formation are confirmed with mass spectrometer measurements. Trimethylamine oxide is capable of forming only one hydrogen bond with sulfuric acid, but unlike amines, trimethylamine oxide can form stable clusters via ion–dipole interactions. That is because of its zwitterionic structure, which causes a high dipole moment. Cluster growth occurs close to the acid:base ratio of 1:1, which is the same as for other monoprotic bases. Enhancement potential of trimethylamine oxide in particle formation is much higher than that of dimethylamine, but lower compared to guanidine. Therefore, at relatively low concentrations and high temperatures, guanidine and trimethylamine oxide may dominate particle formation events over amines.

scholarly journals The charging of neutral dimethylamine and dimethylamine–sulfuric acid clusters using protonated acetone

2015 ◽  
Vol 8 (6) ◽  
pp. 2577-2588
Author(s):  
K. Ruusuvuori ◽  
P. Hietala ◽  
O. Kupiainen-Määttä ◽  
T. Jokinen ◽  
H. Junninen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Chemical Ionization ◽  
Lower Troposphere ◽  
Particle Formation ◽  
Atmospheric Conditions ◽  
Atmospheric Particle ◽  
Organic Bases ◽  
Atmospheric Nucleation ◽  
Quantum Chemical Methods ◽  
Vapour Concentration

Abstract. Sulfuric acid is generally considered one of the most important substances taking part in atmospheric particle formation. However, in typical atmospheric conditions in the lower troposphere, sulfuric acid and water alone are unable to form particles. It has been suggested that strong bases may stabilize sulfuric acid clusters so that particle formation may occur. More to the point, amines – strong organic bases – have become the subject of interest as possible cause for such stabilization. To probe whether amines play a role in atmospheric nucleation, we need to be able to measure accurately the gas-phase amine vapour concentration. Such measurements often include charging the neutral molecules and molecular clusters in the sample. Since amines are bases, the charging process should introduce a positive charge. This can be achieved by, for example, using chemical ionization with a positively charged reagent with a suitable proton affinity. In our study, we have used quantum chemical methods combined with a cluster dynamics code to study the use of acetone as a reagent ion in chemical ionization and compared the results with measurements performed with a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF). The computational results indicate that protonated acetone is an effective reagent in chemical ionization. However, in the experiments the reagent ions were not depleted at the predicted dimethylamine concentrations, indicating that either the modelling scheme or the experimental results – or both – contain unidentified sources of error.

scholarly journals The charging of neutral dimethylamine and dimethylamine-sulphuric acid clusters using protonated acetone

2014 ◽  
Vol 7 (11) ◽  
pp. 11011-11044
Author(s):  
K. Ruusuvuori ◽  
P. Hietala ◽  
O. Kupiainen-Määttä ◽  
T. Jokinen ◽  
H. Junninen ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Chemical Ionization ◽  
Lower Troposphere ◽  
Particle Formation ◽  
Atmospheric Conditions ◽  
Atmospheric Particle ◽  
Organic Bases ◽  
Atmospheric Nucleation ◽  
Quantum Chemical Methods ◽  
Vapour Concentration

Abstract. Sulphuric acid is generally considered one of the most important substances taking part in atmospheric particle formation. However, in typical atmospheric conditions in the lower troposphere sulphuric acid and water alone are unable to form particles. It has been suggested that strong bases may stabilize sulphuric acid clusters so that particle formation may occur. More to the point, amines – strong organic bases – have become the subject of interest as possible cause for such stabilisation. To probe whether amines play a role in atmospheric nucleation, we need to be able to measure accurately the gas-phase amine vapour concentration. Such measurements often include charging the neutral molecules and molecular clusters in the sample. Since amines are bases, the charging process should introduce a positive charge. This can be achieved for example using a positively charged reagent with a suitable proton affinity. In our study, we have used quantum chemical methods combined with a cluster dynamics code to study the use of acetone as a reagent in chemical ionization and compared the results with measurements performed with a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF). The computational results indicate that protonated acetone is an effective reagent in chemical ionization. However, in the experiments the charger ions were not depleted at the predicted dimethylamine concentrations, indicating that either the modelling scheme or the experimental results – or both – contain unidentified sources of error.

scholarly journals From quantum chemical formation free energies to evaporation rates

2012 ◽  
Vol 12 (1) ◽  
pp. 225-235 ◽  
Author(s):  
I. K. Ortega ◽  
O. Kupiainen ◽  
T. Kurtén ◽  
T. Olenius ◽  
O. Wilkman ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Atmospheric Aerosols ◽  
Quantum Chemical ◽  
Local Minimum ◽  
Particle Formation ◽  
Free Energies ◽  
Chemical Methods ◽  
The Past ◽  
Quantum Chemical Methods ◽  
Stable Clusters

Abstract. Atmospheric new particle formation is an important source of atmospheric aerosols. Large efforts have been made during the past few years to identify which molecules are behind this phenomenon, but the actual birth mechanism of the particles is not yet well known. Quantum chemical calculations have proven to be a powerful tool to gain new insights into the very first steps of particle formation. In the present study we use formation free energies calculated by quantum chemical methods to estimate the evaporation rates of species from sulfuric acid clusters containing ammonia or dimethylamine. We have found that dimethylamine forms much more stable clusters with sulphuric acid than ammonia does. On the other hand, the existence of a very deep local minimum for clusters with two sulfuric acid molecules and two dimethylamine molecules hinders their growth to larger clusters. These results indicate that other compounds may be needed to make clusters grow to larger sizes (containing more than three sulfuric acid molecules).

scholarly journals From quantum chemical formation free energies to evaporation rates

2011 ◽  
Vol 11 (10) ◽  
pp. 27327-27357 ◽  
Author(s):  
I. K. Ortega ◽  
O. Kupiainen ◽  
T. Kurtén ◽  
T. Olenius ◽  
O. Wilkman ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Atmospheric Aerosols ◽  
Quantum Chemical ◽  
Local Minimum ◽  
Particle Formation ◽  
Free Energies ◽  
Chemical Methods ◽  
The Past ◽  
Quantum Chemical Methods ◽  
Stable Clusters

Abstract. Atmospheric new particle formation is an important source of atmospheric aerosols. Large efforts have been made during the past few years to identify which molecules are behind this phenomenon, but the actual birth mechanism of the particles is not yet well known. Quantum chemical calculations have proven to be a powerful tool to gain new insights into the very first steps of particle formation. In the present study we use formation free energies calculated by quantum chemical methods to estimate the evaporation rates of species from sulfuric acid clusters containing ammonia or dimethylamine. We have found that dimethylamine forms much more stable clusters with sulphuric acid than ammonia does. On the other hand, the existence of a very deep local minimum for clusters with two sulfuric acid molecules and two dimethylamine molecules hinders their growth to larger clusters. These results indicate that other compounds may be needed to make clusters grow to larger sizes (containing more than three sulfuric acid molecules).

Gas Phase Cluster Formation of Sodium Chloride and Water: Monte Carlo Simulations

1991 ◽  
Vol 46 (4) ◽  
pp. 351-356
Author(s):  
Bernd M. Rode
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Cluster Formation ◽  
Ion Pairs ◽  
Particle Interaction ◽  
Distribution Functions ◽  
Prebiotic Atmosphere ◽  
Low Concentrations ◽  
Phase Cluster ◽  
Simulation Parameters

Abstract Monte Carlo simulations of a system of 200 water and 24 NaCl molecules at 6 different densities in the range from 0.003 g/cm3 to 0.999 g,/cm3 and T = 125 °C and 225 CC were performed to obtain some insight into cluster formation which should precede and determine the formation of aerosol structures and has possibly played some role in prebiotic atmosphere chemistry. Solute hydration occurs already at very low concentrations mainly in the form of hydrated molecules ("contact ion pairs"). At higher densities larger cluster structures are observed, leading rather continuously to the structure of the supersaturated 7.1 M NaCl solution at the same temperature. Radial distribution functions, coordination numbers and particle interaction energies are discussed with respect to the simulation parameters density and temperature

scholarly journals Particle concentration and flux dynamics in the atmospheric boundary layer as the indicator of formation mechanism

2011 ◽  
Vol 11 (12) ◽  
pp. 5591-5601 ◽  
Author(s):  
J. Lauros ◽  
A. Sogachev ◽  
S. Smolander ◽  
H. Vuollekoski ◽  
S.-L. Sihto ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Formation Mechanism ◽  
Turbulent Transport ◽  
Particle Formation ◽  
Formation Mechanisms ◽  
Forest Site ◽  
Aerosol Formation ◽  
Flux Dynamics ◽  
Layer Deposition

Abstract. We carried out column model simulations to study particle fluxes and deposition and to evaluate different particle formation mechanisms at a boreal forest site in Finland. We show that kinetic nucleation of sulphuric acid cannot be responsible for new particle formation alone as the simulated vertical profile of particle number concentration does not correspond to observations. Instead organic induced nucleation leads to good agreement confirming the relevance of the aerosol formation mechanism including organic compounds emitted by the biosphere. The simulation of aerosol concentration within the atmospheric boundary layer during nucleation event days shows a highly dynamical picture, where particle formation is coupled with chemistry and turbulent transport. We have demonstrated the suitability of our turbulent mixing scheme in reproducing the most important characteristics of particle dynamics within the boundary layer. Deposition and particle flux simulations show that deposition affects noticeably only the smallest particles in the lowest part of the atmospheric boundary layer.

scholarly journals SO<sub>2</sub> and NH<sub>3</sub> emissions enhance organosulfur compounds and fine particle formation from the photooxidation of a typical aromatic hydrocarbon

2021 ◽  
Vol 21 (10) ◽  
pp. 7963-7981
Author(s):  
Zhaomin Yang ◽  
Li Xu ◽  
Narcisse T. Tsona ◽  
Jianlong Li ◽  
Xin Luo ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Oxidation Mechanism ◽  
Particle Formation ◽  
Urban Atmosphere ◽  
Mass Spectrometry Analysis ◽  
Formation Mechanisms ◽  
Chemical Compositions ◽  
Organosulfur Compounds ◽  
Aerosol Formation ◽  
Secondary Aerosol

Abstract. Aromatic hydrocarbons can dominate the volatile organic compound budget in the urban atmosphere. Among them, 1,2,4-trimethylbenzene (TMB), mainly emitted from solvent use, is one of the most important secondary organic aerosol (SOA) precursors. Although atmospheric SO2 and NH3 levels can affect secondary aerosol formation, the influenced extent of their impact and their detailed driving mechanisms are not well understood. The focus of the present study is to examine the chemical compositions and formation mechanisms of SOA from TMB photooxidation influenced by SO2 and/or NH3. Here, we show that SO2 emission could considerably enhance aerosol particle formation due to SO2-induced sulfate generation and acid-catalyzed heterogeneous reactions. Orbitrap mass spectrometry measurements revealed the generation of not only typical TMB products but also hitherto unidentified organosulfates (OSs) in SO2-added experiments. The OSs designated as being of unknown origin in earlier field measurements were also detected in TMB SOA, indicating that atmospheric OSs might also be originated from TMB photooxidation. For NH3-involved experiments, results demonstrated a positive correlation between NH3 levels and particle volume as well as number concentrations. The effects of NH3 on SOA composition were slight under SO2-free conditions but stronger in the presence of SO2. A series of multifunctional products with carbonyl, alcohols, and nitrate functional groups were tentatively characterized in NH3-involved experiments based on infrared spectra and mass spectrometry analysis. Plausible formation pathways were proposed for detected products in the particle phase. The volatility distributions of products, estimated using parameterization methods, suggested that the detected products gradually condense onto the nucleation particles to contribute to aerosol formation and growth. Our results suggest that strict control of SO2 and NH3 emissions might remarkably reduce organosulfates and secondary aerosol burden in the atmosphere. Updating the aromatic oxidation mechanism in models could result in more accurate treatment of particle formation for urban regions with considerable SO2, NH3, and aromatics emissions.

Ion-induced iodic acid nucleation

2021 ◽  
Author(s):  
Xu-Cheng He ◽  
Siddharth Iyer ◽  
Yee Jun Tham ◽  
Mikko Sipilä ◽  
Jasper Kirkby ◽  
...  
Keyword(s):  
Time Evolution ◽  
Marine Boundary Layer ◽  
Cluster Formation ◽  
Particle Formation ◽  
Galactic Cosmic Rays ◽  
Oxidation Products ◽  
Formation Processes ◽  
Iodic Acid ◽  
Nucleation Mechanisms ◽  
Iodine Oxides

&lt;p&gt;Aside from capable of influencing atmospheric oxidation capacity, iodine species are known to contribute to particle formation processes. Iodine particle formation was commonly believed to be important in coastal regions only, e.g. Mace Head, but emerging evidence shows that it also plays an important role in Arctic regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Although the nucleation mechanisms have been proposed to involve mainly iodine oxides, recent field observations suggest that HIO&lt;sub&gt;3&lt;/sub&gt; plays a key role in the cluster formation processes. Despite these advances, experiments with atmospherically relevant vapor concentrations are lacking and the time evolution of charged cluster formation processes has never been detected at the molecular level to validate the mechanisms observed in the field.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;In this study, we carried out iodine particle formation experiments in the CLOUD chamber at CERN. The precursor vapor (I&lt;sub&gt;2&lt;/sub&gt;) and oxidation products were carefully controlled at concentrations relevant to those in marine boundary layer conditions. Natural galactic cosmic rays were used to produce ions in the chamber which further initiated ion-induced nucleation processes. An atmospheric pressure interface time-of-flight mass spectrometer was used to trace the time evolution of charged iodine clusters which revealed HIO&lt;sub&gt;3&lt;/sub&gt; as the major contributor.&lt;/p&gt;

scholarly journals Predicting atmospheric particle formation days by Bayesian classification of the time series features

Tellus B ◽  
2018 ◽  
Vol 70 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. A. Zaidan ◽  
V. Haapasilta ◽  
R. Relan ◽  
H. Junninen ◽  
P. P. Aalto ◽  
...  
Keyword(s):  
Time Series ◽  
Particle Formation ◽  
Bayesian Classification ◽  
Atmospheric Particle
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