Effect of surface–bulk partitioning on the heterogeneous oxidation of aqueous saccharide aerosols
Effect of surface–bulk partitioning on the heterogeneous oxidation of aqueous saccharide aerosols
复制标题
表面-本体分配对水糖气溶胶非均相氧化的影响
DOI：
10.1039/c8cp06785f
复制
发表时间：
2019
影响因子：
3.3
通讯作者：
Goulay, Fabien
中科院分区：
文献类型：
--
作者：
Fan, Hanyu;Wenyika Masaya, Tadini;Goulay, Fabien
利用常压流动管与颗粒组成的离线分析相结合的方法，研究了混合糖水溶液的非均相氧化反应。对于等摩尔单糖/双糖水溶胶混合物，双糖的衰变速度明显慢于单糖。混合水溶液的分子动力学模拟表明，在水面以下形成了∼10？二糖排斥层。建立了一个简单的化学模型，讨论了双糖表面分配对多相动力学的可能影响。观察到的衰变与颗粒中二糖在界面处的OH自由基空间重叠较差相一致。讨论了分配对大气有机气溶胶非均相氧化的影响。
The OH-initiated heterogeneous oxidation of mixed saccharide aqueous aerosols is investigated using an atmospheric-pressure flow tube coupled to off-line analysis of the particle composition. For equimolar monosaccharide/disaccharide aqueous aerosol mixtures, the decay of the disaccharide is found to be significantly slower than that of the monosaccharide. Molecular dynamics simulations of the mixed aqueous solutions reveal the formation of a ∼10 Å disaccharide exclusion layer below the water surface. A simple chemical model is developed to discuss the possible effect of the disaccharide surface partitioning on the heterogeneous kinetics. The observed decays are consistent with a poor spatial overlap of the OH radical at the interface with the disaccharide in the particle bulk. The effect of partitioning on the heterogeneous oxidation of atmospheric organic aerosols is discussed.