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Full-Text Articles in Physical Sciences and Mathematics

Hygroscopic Growth Of Ammonium Sulfate/Dicarboxylic Acids, Matthew E. Wise, Jason D. Surratt, Daniel B. Curtis, John E. Shilling, Margaret A. Tolbert Oct 2003

Hygroscopic Growth Of Ammonium Sulfate/Dicarboxylic Acids, Matthew E. Wise, Jason D. Surratt, Daniel B. Curtis, John E. Shilling, Margaret A. Tolbert

CUP Faculty Research

Recent studies have shown that tropospheric sulfate aerosols commonly contain 50% by mass organic species. The influence of these organics on the chemical and physical properties of sulfate aerosols is not fully established. We have measured the water activity of pure dicarboxylic acids and eutonic mixtures of ammonium sulfate/dicarboxylic acids at 25°C and have calculated van't Hoff factors for each individual system. We have also used the vapor pressure data to determine the hygroscopic growth curves for pure dicarboxylic acids and eutonic mixtures and provide power law fits to the data. For the systems studied we find that the presence …


Phase Changes In Internally Mixed Maleic Acid/Ammonium Sulfate Aerosols, Sarah D. Brooks, Rebecca M. Garland, Matthew E. Wise, Anthony J. Prenni, Melinda Cushing, Erika Hewitt, Margaret A. Tolbert Aug 2003

Phase Changes In Internally Mixed Maleic Acid/Ammonium Sulfate Aerosols, Sarah D. Brooks, Rebecca M. Garland, Matthew E. Wise, Anthony J. Prenni, Melinda Cushing, Erika Hewitt, Margaret A. Tolbert

CUP Faculty Research

A temperature controlled flow tube system equipped with Fourier transform infrared (FTIR) detection of particle phase and relative humidity was used to measure the deliquescence and efflorescence of ammonium sulfate, maleic acid, and internally mixed maleic acid/ammonium sulfate particles. Our results indicate that maleic acid aerosols begin to take up water starting at a low relative humidity, ∼20%, and continue the constant uptake of water until the final deliquescence relative humidity (DRH), 89%, is reached. Internally mixed particles containing maleic acid and ammonium sulfate were found to deliquesce at a lower relative humidity (RH) than either of the pure species. …


Solubility And Freezing Effects Of Fe2+ And Mg2+ In H2so4 Solutions Representative Of Upper Tropospheric And Lower Stratospheric Sulfate Particles, Matthew E. Wise, Sarah D. Brooks, Rebecca M. Garland, Daniel J. Cziczo, Scot T. Martin, Margaret A. Tolbert Jul 2003

Solubility And Freezing Effects Of Fe2+ And Mg2+ In H2so4 Solutions Representative Of Upper Tropospheric And Lower Stratospheric Sulfate Particles, Matthew E. Wise, Sarah D. Brooks, Rebecca M. Garland, Daniel J. Cziczo, Scot T. Martin, Margaret A. Tolbert

CUP Faculty Research

Chemical elements characteristic of earth minerals and meteorites are present within background tropospheric and stratospheric sulfate aerosol particles. However, it is unknown if these elements are present predominantly as solids, including possible sulfates, carbonates, and oxides, or rather as soluble aqueous metal ions or complexes. Further, it is unclear how these impurities could affect particle freezing. To address these questions, we have determined the total equilibrium metal solubility ([Fe2+]T and [Mg2+]T) in 20–90 wt % sulfuric acid solutions over the temperature range 200–300 K. We have measured solubilities using samples of MgSO4 …