Abstract：With combination of a pulse relative humidity (RH) controlling system and rapid scan vacuum FTIR technique, dynamic hygroscopicity of aerosol can be studied during pulse RH process. The time-resolved FTIR spectra can provide both water content of aerosols and water vapor amount of the aerosol ambient in sub-second time resolution. Experiments were performed on sodium nitrate, magnesium sulfate and magnesium nitrate aerosols. By comparing their hygroscopicity in pulse RH process and quasi-equilibrium state, for sodium nitrate aerosols, under time resolution of 0.12 s, we didn’t see water transfer delay between aerosols and ambient environment. For magnesium sulfate aerosols, after gel formation, the water transfer speed is limited by the aerosol bulk phase. While for aged magnesium nitrate aerosols, non-soluble species generated and formed a film on the surface of aerosol particles, which slow down the water exchange rate between aerosols and ambient environment. This method turned out to be an efficient and convenient tool to elucidate the water transfer process controlled by bulk and surface for aerosols.
Key words：Relative humidity pulse;Aerosol;Mass transfer process
张 云，庞树峰，张韫宏* . 脉动相对湿度方法观测由体相及界面控制的气溶胶传质过程 [J]. 光谱学与光谱分析, 2016, 36(03): 887-889.
ZHANG Yun, PANG Shu-feng, ZHANG Yun-hong* . A Relative Humidity Pulse Approach to Observe Mass Transfer Processes Controlled by Bulk and Surface for Aerosols. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(03): 887-889.
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