Yong Liu (6908)Alexander Laskin (1354857)
The hygroscopic behavior of CH<sub>3</sub>SO<sub>3</sub>Na, CH<sub>3</sub>SO<sub>3</sub>NH<sub>4</sub>, (CH<sub>3</sub>SO<sub>3</sub>)<sub>2</sub>Mg, and (CH<sub>3</sub>SO<sub>3</sub>)<sub>2</sub>Ca particles as a function of relative humidity (RH) has been studied using microscopic Fourier transform infrared (micro-FTIR) spectroscopy. The approach used exposure of substrate-deposited, ∼1 μm dry-size particles to humidified nitrogen followed by micro-FTIR spectroscopy over a selected sample area. The results show that CH<sub>3</sub>SO<sub>3</sub>Na particles undergo characteristic phase transitions at deliquescence relative humidity (DRH) of 71% and efflorescence relative humidity (ERH) of ∼40%. In contrast, CH<sub>3</sub>SO<sub>3</sub>NH<sub>4</sub>, (CH<sub>3</sub>SO<sub>3</sub>)<sub>2</sub>Mg, and (CH<sub>3</sub>SO<sub>3</sub>)<sub>2</sub>Ca particles do not undergo phase transitions and exhibit continuous, reversible uptake and evaporation of water under the influence of changing RH. The extent of water uptake is quantified and presented as water-to-solute ratios (WSR) in particles as a function of RH. The WSR values are determined from the integrated absorbance of the water and the solute-specific bands in IR spectra recorded at different RH.
Paolo Sebastianelli (5234441)Pablo M. Cometto (1627615)Rodolfo G. Pereyra (5234438)
Jürgen O. Daiss (2649646)Katrin A. Barth (2704345)Christian Burschka (1724161)Patrick Hey (2704354)Rainer Ilg (2490280)Karsten Klemm (2704351)Ingo Richter (2703022)Stephan A. Wagner (2704348)Reinhold Tacke (1561765)
Zhen-Zhen Xu (2126308)Hong-Jun Fan (1799563)
Rafael ValienteLuís LezamaFernando RodríguezM. Valle
Zhong-Xia Wang (665287)Yi Zhang (9093)Yuan-Yuan Tang (3188598)Peng-Fei Li (577606)Ren-Gen Xiong (1510501)