Thermodynamics of the formation of atmospheric organic particulate matter by accretion reactions - 2. Dialdehydes, methylglyoxal, and diketones
Thermodynamics of the formation of atmospheric organic particulate matter by accretion reactions - 2. Dialdehydes, methylglyoxal, and diketones
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DOI：
10.1016/j.atmosenv.2005.07.056
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发表时间：
2005-11-01
影响因子：
5
通讯作者：
Pankow, JF
中科院分区：
文献类型：
--
作者：
Barsanti, KC;Pankow, JF
通过吸收性气体/颗粒分配来预测大气中有机颗粒物（OPM）的形成，需要了解所有可凝结物质的特性、大气含量和物理性质。来自现场和实验室实验的数据表明，一部分大气有机颗粒物样本是由挥发性有机化合物氧化过程中产生的产物组成的。有人提出，这些最初形成的氧化产物中的一些也通过分子量（MW）增长“聚积反应”促进了大气有机颗粒物的形成。此类反应的作用以及评估它们在大气有机颗粒物形成方面的热力学相关性的一般理论方法，在先前的研究中已经进行了讨论。本研究在考虑乙二醛、另外两种二醛、甲基乙二醛和两种二酮的聚积反应时运用了该方法。用于预测生成自由能（ΔG(f)°）值（以及因此的平衡常数（K）值）的方法表明：（1）对于1,4 - 丁二醛、2,3 - 丁二酮和2,5 - 己二酮，所考虑的聚积反应是不利的；（2）对于C - 6及更高的二醛，如果在动力学上有利，通过羟醛缩合的反应在某些情况下可能有助于大气有机颗粒物的形成；（3）对于乙二醛，二醇及后续低聚物的形成，以及对于甲基乙二醛，羟醛缩合在热力学上是有利的，如果在动力学上有利，可能对大气中的有机颗粒物有显著贡献。（c）2005爱思唯尔有限公司。保留所有权利。
Predicting the formation of organic particulate matter (OPM) in the atmosphere by absorptive gas/particle partitioning requires a knowledge of the identities, atmospheric levels, and physical properties of all condensable species. Data from field and chamber experiments have shown that a portion of atmospheric OPM samples are comprised of products generated during oxidation of volatile organic compounds. It has been suggested that some of these initially formed oxidation products also contribute to the formation of atmospheric OPM via molecular-weight (MW) building "accretion reactions". The role of such reactions as well as a general theoretical approach for evaluating their thermodynamic relevance in regard to atmospheric OPM formation, have been discussed in prior work. This work utilizes that approach in considerations of accretion reactions of glyoxal, two other dialdehydes, methylglyoxal, and two diketones. The methods used to predict free energy of formation (Delta G(f)degrees) values (and hence equilibrium constant (K) values) indicate that: (1) for 1,4-butanedial, 2,3-butanedione, and 2,5-hexanedione, the accretion reactions considered are not favorable; (2) for C-6 and higher dialdehydes, reaction by aldol condensation may contribute to atmospheric OPM formation under certain circumstances, if kinetically favorable; and (3) for glyoxal, diol and subsequent oligomer formation, and for methylglyoxal, aldol condensation, are thermodynamically favorable, and may contribute significantly to OPM in the atmosphere, if kinetically favorable. (c) 2005 Elsevier Ltd. All rights reserved.