Interfacial Tensions of Aged Organic Aerosol Particle Mimics Using a Biphasic Microfluidic Platform
| Autor: | Hallie C. Boyer, Andrew R. Metcalf, Cari S. Dutcher |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Ammonium sulfate
010504 meteorology & atmospheric sciences Microfluidics 02 engineering and technology 01 natural sciences Surface tension chemistry.chemical_compound Formaldehyde Surface Tension Environmental Chemistry Organic Chemicals Sulfate Microscale chemistry 0105 earth and related environmental sciences Aerosols Aqueous solution Atmosphere Water General Chemistry Particulates Pyruvaldehyde 021001 nanoscience & nanotechnology Aerosol Solutions chemistry Chemical engineering Ammonium Sulfate Environmental chemistry Particle Particulate Matter Gases 0210 nano-technology |
| Zdroj: | Environmental Science & Technology. 50:1251-1259 |
| ISSN: | 1520-5851 0013-936X |
| Popis: | Secondary organic aerosol (SOA) particles are a major component of atmospheric particulate matter, yet their formation processes and ambient properties are not well understood. These complex particles often contain multiple interfaces due to internal aqueous- and organic-phase partitioning. Aerosol interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which ambient organic vapors interact with suspended particles. To accurately predict the evolution of SOA in the atmosphere, we must improve our understanding of aerosol interfaces. In this work, biphasic microscale flows are used to measure interfacial tension of reacting methylglyoxal, formaldehyde, and ammonium sulfate aqueous mixtures with a surrounding oil phase. Our experiments show a suppression of interfacial tension as a function of organic content that remains constant with reaction time for methylglyoxal-ammonium sulfate systems. We also reveal an unexpected time dependence of interfacial tension over a period of 48 h for ternary solutions of both methylglyoxal and formaldehyde in aqueous ammonium sulfate, indicating a more complicated behavior of surface activity where there is competition among dissolved organics. From these interfacial tension measurements, the morphology of aged atmospheric aerosols with internal liquid-liquid phase separation is inferred. |
| Databáze: | OpenAIRE |
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