10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Hygroscopicity Dependent Upon Reaction Between Components in Internally Mixed Sodium Pyruvate and Ammonium Sulfate Aerosols
Hui Yang, PANG SHUFENG, Yunhong Zhang, Beijing Institute of Technology
Abstract Number: 59 Working Group: Aerosol Chemistry
Abstract In atmosphere, some compounds are mixed in a particle. The chemical reaction between components can lead to gas-particle repartition of volatile species, which has the important effect on SOA formation and climate. Herein, the reaction between sodium pyruvate and ammonium sulfate was monitored by using the attenuated total reflectance Fourier transform infrared (ATR-FTIR).
With decreasing RH, the feature bands of sodium pyruvate and ammonium sulfate decreased gradually, indicating a depletion of sodium pyruvate and ammonium sulfate. At 65.5 % RH, a sharp and narrow peak at 1132 cm−1 appeared, which is accompanied by the degration of the band at 1095 cm-1 into a weak shoulder, suggesting the formation of crystalline sodium sulfate. As the continuous decrease in RH, the 1132 cm-1 peak became stronger, indicating more crystal sodium sulfate. So it can be concluded that the reaction between sodium pyruvate and ammonium sulfate reduced to sodium sulfate and release of ammonia and pyruvic acid release.
When the RH take a cyclic change, water content decreased to ~50% or original droplets. In the second RH cycle, water content can restore. So the water content decrease should rise from the particulate reaction which ended after a RH cycle. Because of changeable compositions, the efflorescence RH on second dehumidifying was 67.1%, slightly higher than that of 64.2% on first dehydration.