Critical assessment of liquid density estimation methods for multifunctional organic compounds and their use in atmospheric science.
Critical assessment of liquid density estimation methods for multifunctional organic compounds and their use in atmospheric science.
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DOI：
10.1021/jp304547r
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发表时间：
2013-04
期刊：
影响因子：
--
通讯作者：
M. Barley;D. Topping;G. Mcfiggans
中科院分区：
文献类型：
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作者：
M. Barley;D. Topping;G. Mcfiggans
为了模拟二次有机气溶胶（SOA）的性质和化学组成，需要估计数千种有机化合物的物理性质数据。七种方法估计液体密度进行评估，对实验数据的测试集的56个多功能有机化合物。Schroeder的基团贡献法与Nannoolal的使用临界性质的Rackett方程相结合，得到了该测试集的最佳液体密度值。在这项工作中，确定了某些基团（芳香胺和酚）的临界性质估计方法中的一些问题，突出了从高质量的实验数据中导出基团贡献方法参数的重要性（和困难）。选择的估计方法适用于2742化合物的大气化学机制，这表明，他们提供了一致的液体密度值的化合物等大气重要的（但研究不足）的官能团，如氢过氧化物，过氧化物，过氧酸，PAN。估计液体密度值也提出了一个选择的化合物预测是重要的大气SOA。吸湿增长因子（预期取决于液体密度的属性）已被计算为广泛的颗粒组合物。结果表明，生长因子对液体密度的敏感性较低，可采用1350 kg·m（-3）的单一密度值计算生长因子，与实验室或现场实测值比较，误差不大。
In order to model the properties and chemical composition of secondary organic aerosol (SOA), estimated physical property data for many thousands of organic compounds are required. Seven methods for estimating liquid density are assessed against experimental data for a test set of 56 multifunctional organic compounds. The group contribution method of Schroeder coupled with the Rackett equation using critical properties by Nannoolal was found to give the best liquid density values for this test set. During this work some problems with the representation of certain groups (aromatic amines and phenols) within the critical property estimation methods were identified, highlighting the importance (and difficulties) of deriving the parameters of group contribution methods from good quality experimental data. A selection of the estimation methods are applied to the 2742 compounds of an atmospheric chemistry mechanism, which showed that they provided consistent liquid density values for compounds with such atmospherically important (but poorly studied) functional groups as hydroperoxide, peroxide, peroxyacid, and PAN. Estimated liquid density values are also presented for a selection of compounds predicted to be important in atmospheric SOA. Hygroscopic growth factor (a property expected to depend on liquid density) has been calculated for a wide range of particle compositions. A low sensitivity of the growth factor to liquid density was found, and a single density value of 1350 kg·m(-3) could be used for all multicomponent SOA in the calculation of growth factors for comparison with experimentally measured values in the laboratory or the field without incurring significant error.