Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Phys Chem Chem Phys. 2012 Jan 28;14(4):1468-79. doi: 10.1039/c1cp22716e. Epub 2011 Dec 12.
The heterogeneous reactions of hydroxyl radicals (OH) with squalane and bis(2-ethylhexyl) sebacate (BES) particles are used as model systems to examine how distributions of reaction products evolve during the oxidation of chemically reduced organic aerosol. A kinetic model of multigenerational chemistry, which is compared to previously measured (squalane) and new (BES) experimental data, reveals that it is the statistical mixtures of different generations of oxidation products that control the average particle mass and elemental composition during the reaction. The model suggests that more highly oxidized reaction products, although initially formed with low probability, play a large role in the production of gas phase reaction products. In general, these results highlight the importance of considering atmospheric oxidation as a statistical process, further suggesting that the underlying distribution of molecules could play important roles in aerosol formation as well as in the evolution of key physicochemical properties such as volatility and hygroscopicity.
羟基自由基 (OH) 与角鲨烷和双 (2-乙基己基) 癸二酸酯 (BES) 颗粒的多相反应被用作模型体系，以研究在化学还原的有机气溶胶氧化过程中，反应产物的分布如何演变。多代化学动力学模型与之前测量的（角鲨烷）和新的（BES）实验数据进行了比较，结果表明，控制反应过程中平均颗粒质量和元素组成的是不同代氧化产物的统计混合物。该模型表明，尽管最初形成的概率较低，但更高氧化程度的反应产物在气相反应产物的生成中起着重要作用。总的来说，这些结果强调了将大气氧化视为一个统计过程的重要性，进一步表明分子的基础分布可能在气溶胶形成以及挥发性和吸湿性等关键物理化学性质的演变中发挥重要作用。
