A predictive model for salt nanoparticle formation using heterodimer stability calculations
<p>Acid–base clusters and stable salt formation are critical drivers of new particle formation events in the atmosphere. In this study, we explore salt heterodimer (a cluster of one acid and one base) stability as a function of gas-phase acidity, aqueous-phase acidity, heterodimer proton tran...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-08-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/21/11637/2021/acp-21-11637-2021.pdf |
| _version_ | 1818356688503177216 |
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| author | S. Chee K. Barsanti J. N. Smith N. Myllys N. Myllys |
| author_facet | S. Chee K. Barsanti J. N. Smith N. Myllys N. Myllys |
| author_sort | S. Chee |
| collection | DOAJ |
| description | <p>Acid–base clusters and stable salt formation are critical drivers of new particle formation events in the atmosphere. In this study, we explore salt heterodimer (a cluster of one acid and one base) stability as a function of gas-phase acidity, aqueous-phase acidity, heterodimer proton transference, vapor pressure, dipole moment and polarizability for salts comprised of sulfuric acid, methanesulfonic acid and nitric acid with nine bases. The best predictor of heterodimer stability was found to be gas-phase acidity. We then analyzed the relationship between heterodimer stability and <span class="inline-formula"><i>J</i><sub>4×4</sub></span>, the theoretically predicted formation rate of a four-acid, four-base cluster, for sulfuric acid salts over a range of monomer concentrations from <span class="inline-formula">10<sup>5</sup></span> to <span class="inline-formula">10<sup>9</sup></span> molec cm<span class="inline-formula"><sup>−3</sup></span> and temperatures from 248 to 348 K and found that heterodimer stability forms a lognormal relationship with <span class="inline-formula"><i>J</i><sub>4×4</sub></span>. However, temperature and concentration effects made it difficult to form a predictive expression of <span class="inline-formula"><i>J</i><sub>4×4</sub></span>. In order to reduce those effects, heterodimer concentration was calculated from heterodimer stability and yielded an expression for predicting <span class="inline-formula"><i>J</i><sub>4×4</sub></span> for any salt, given approximately equal acid and base monomer concentrations and knowledge of monomer concentration and temperature. This parameterization was tested for the sulfuric acid–ammonia system by comparing the predicted values to experimental data and was found to be accurate within 2 orders of magnitude. We show that one can create a simple parameterization that incorporates the dependence on temperature and monomer concentration on <span class="inline-formula"><i>J</i><sub>4×4</sub></span> by defining a new term that we call the normalized heterodimer concentration, <span class="inline-formula">Φ</span>. A plot of <span class="inline-formula"><i>J</i><sub>4×4</sub></span> vs. <span class="inline-formula">Φ</span> collapses to a single monotonic curve for weak sulfate salts (difference in gas-phase acidity <span class="inline-formula">>95</span> kcal mol<span class="inline-formula"><sup>−1</sup></span>) and can be used to accurately estimate <span class="inline-formula"><i>J</i><sub>4×4</sub></span> within 2 orders of magnitude in atmospheric models.</p> |
| first_indexed | 2024-12-13T20:01:11Z |
| format | Article |
| id | doaj.art-20f75bec28e745aaa0c7376fcc639b77 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-13T20:01:11Z |
| publishDate | 2021-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-20f75bec28e745aaa0c7376fcc639b772022-12-21T23:33:11ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242021-08-0121116371165410.5194/acp-21-11637-2021A predictive model for salt nanoparticle formation using heterodimer stability calculationsS. Chee0K. Barsanti1J. N. Smith2N. Myllys3N. Myllys4Department of Chemistry, University of California, Irvine, CA, USADepartment of Chemical & Environmental Engineering, University of California, Riverside, CA, USADepartment of Chemistry, University of California, Irvine, CA, USADepartment of Chemistry, University of California, Irvine, CA, USADepartment of Chemistry, University of Jyväskylä, Jyväskylä, Finland<p>Acid–base clusters and stable salt formation are critical drivers of new particle formation events in the atmosphere. In this study, we explore salt heterodimer (a cluster of one acid and one base) stability as a function of gas-phase acidity, aqueous-phase acidity, heterodimer proton transference, vapor pressure, dipole moment and polarizability for salts comprised of sulfuric acid, methanesulfonic acid and nitric acid with nine bases. The best predictor of heterodimer stability was found to be gas-phase acidity. We then analyzed the relationship between heterodimer stability and <span class="inline-formula"><i>J</i><sub>4×4</sub></span>, the theoretically predicted formation rate of a four-acid, four-base cluster, for sulfuric acid salts over a range of monomer concentrations from <span class="inline-formula">10<sup>5</sup></span> to <span class="inline-formula">10<sup>9</sup></span> molec cm<span class="inline-formula"><sup>−3</sup></span> and temperatures from 248 to 348 K and found that heterodimer stability forms a lognormal relationship with <span class="inline-formula"><i>J</i><sub>4×4</sub></span>. However, temperature and concentration effects made it difficult to form a predictive expression of <span class="inline-formula"><i>J</i><sub>4×4</sub></span>. In order to reduce those effects, heterodimer concentration was calculated from heterodimer stability and yielded an expression for predicting <span class="inline-formula"><i>J</i><sub>4×4</sub></span> for any salt, given approximately equal acid and base monomer concentrations and knowledge of monomer concentration and temperature. This parameterization was tested for the sulfuric acid–ammonia system by comparing the predicted values to experimental data and was found to be accurate within 2 orders of magnitude. We show that one can create a simple parameterization that incorporates the dependence on temperature and monomer concentration on <span class="inline-formula"><i>J</i><sub>4×4</sub></span> by defining a new term that we call the normalized heterodimer concentration, <span class="inline-formula">Φ</span>. A plot of <span class="inline-formula"><i>J</i><sub>4×4</sub></span> vs. <span class="inline-formula">Φ</span> collapses to a single monotonic curve for weak sulfate salts (difference in gas-phase acidity <span class="inline-formula">>95</span> kcal mol<span class="inline-formula"><sup>−1</sup></span>) and can be used to accurately estimate <span class="inline-formula"><i>J</i><sub>4×4</sub></span> within 2 orders of magnitude in atmospheric models.</p>https://acp.copernicus.org/articles/21/11637/2021/acp-21-11637-2021.pdf |
| spellingShingle | S. Chee K. Barsanti J. N. Smith N. Myllys N. Myllys A predictive model for salt nanoparticle formation using heterodimer stability calculations Atmospheric Chemistry and Physics |
| title | A predictive model for salt nanoparticle formation using heterodimer stability calculations |
| title_full | A predictive model for salt nanoparticle formation using heterodimer stability calculations |
| title_fullStr | A predictive model for salt nanoparticle formation using heterodimer stability calculations |
| title_full_unstemmed | A predictive model for salt nanoparticle formation using heterodimer stability calculations |
| title_short | A predictive model for salt nanoparticle formation using heterodimer stability calculations |
| title_sort | predictive model for salt nanoparticle formation using heterodimer stability calculations |
| url | https://acp.copernicus.org/articles/21/11637/2021/acp-21-11637-2021.pdf |
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