Deliquescence Relative Humidity and Reversible Non-deliquescent Water Uptake in the Sodium Salts of Succinic Acid

Abstract

When metal ions from sea spray and other sources interact with dicarboxylic acids dissolved in atmospheric droplets, the results can be the precipitate of organic salts under dry atmospheric conditions. This study focused on the hygroscopic properties of the sodium salts of succinic acid (NaHC4H4O4 and Na2C4H4O4). The salts reversibly take up water at relative humidities (RHs) lower than the deliquescence relative humidity (DRH) at 298 K. At higher RH values, a normal DRH is observed and temperature-dependent values were determined. The enhanced water content of otherwise dry particles may have an impact on heterogeneous chemistry on these particles as well as their optical properties.

Mario Molina Memorial Special Issue

“…The thermodynamics of aerosols, including their acidity and phase changes, impact atmospheric chemistry and climate. Molina and colleagues pioneered creative approaches combining spectroscopy, microscopy, and calorimetry to study phase behavior in droplets and aerosols. , Changes in the particle phase and morphology as a result of liquid–liquid phase separation, reverse micelle formation, and crystallization or glass formation can impact mass transfer, including reactive uptake , and water uptake, or impact particle-phase chemical kinetics . The acidity may differ between the bulk and interface of aqueous droplets .…”