[摘要] The uptake kinetics of gaseous ClONO
2 and BrONO
2 on aqueoussurfaces were measured, as a function of temperature and liquid composition(pure water and NaCl or NaBr containing solutions) using the droplet traintechnique coupled to a mass spectrometer. The uptake kinetics are driven bythe reactivity of these gases and, for both compounds, the uptake rates onpure water or on NaCl solutions (0.1M) are comparable. The uptakecoefficient γ of ClONO
2 does not depend on the temperaturewhile that of BrONO
2 increases slightly when the temperature is raisedfrom 272 to 280K. For ClONO
2 and BrONO
2, the uptake ratesincrease on NaBr-doped droplets, enabling the estimation of the massaccommodation coefficient α. The corresponding values for αare 0.108±0.033 for ClONO
2 and 0.063±0.021 forBrONO
2 where the statistical errors correspond to ±2σ.
The reactions of ClONO2 and BrONO2 on NaCl solutions leadrespectively to the formation of Cl2 and BrCl. The uptake ofClONO2 on NaBr solutions generates BrCl as primary product, which inturn can react with NaBr to produce Br2. As expected, the only productof BrONO2 reaction on NaBr solution is Br2.
