Hygroscopicity of polycatechol and polyguaiacol secondary organic aerosol in sub- and supersaturated water vapor environments
Hygroscopicity of polycatechol and polyguaiacol secondary organic aerosol in sub- and supersaturated water vapor environments
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亚饱和和过饱和水蒸气环境中聚儿茶酚和聚愈创木酚二次有机气溶胶的吸湿性
DOI：
10.1039/d1ea00063b
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Asa-Awuku, Akua A.
中科院分区：
文献类型：
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作者：
Malek, Kotiba A.;Gohil, Kanishk;Al-Abadleh, Hind A.;Asa-Awuku, Akua A.
聚儿茶酚和聚愈创木酚是吸光且不溶于水的颗粒，它们通过铁催化反应与生物质燃烧排放物中的芳香族化合物有效形成。关于它们的吸水性和云或雾滴形成能力的定量信息知之甚少。本研究在实验室合成了聚儿茶酚和聚愈创木酚颗粒，并分别使用吸湿性串联微分迁移率分析仪（H-TDMA）和云凝结核计数器（CCNC）在亚饱和和过饱和相对湿度（RH）条件下研究了它们的云凝结成核效率。实验结果表明，两种聚合物材料均具有轻微吸湿性，其单一吸湿性参数（κ）范围为0.03~0.25，处于二次有机气溶胶（SOA）的κ范围内。聚儿茶酚比聚愈创木酚更具吸湿性，这是由于它们的结构差异所致。聚愈创木酚与其他不溶性有机化合物具有相似的吸水性，并且可以使用 Brunauer-Emmett-Teller (BET) 或 Frankel Hill Hershey 吸附等温理论 (FHH-AT) 很好地模拟液滴形成。两种聚合物材料在0.5至30 g L−1范围内都没有很强的表面活性，因此过饱和和过饱和吸湿性测量的差异并不归因于表面活性材料的存在。相反，这是由于化学品和 H-TDMA 的溶解度限制是由水吸附驱动的。这些结果的含义是在气溶胶与云相互作用的背景下讨论的，这些相互作用来自主要和次要来源的气溶胶的吸湿性。
Polycatechol and polyguaiacol are light-absorbing and water-insoluble particles that efficiently form from iron-catalyzed reactions with aromatic compounds from biomass burning emissions. Little quantitative information is known about their water uptake and cloud or haze droplet formation ability. In this study, polycatechol and polyguaiacol particles were synthesized in the laboratory, and their cloud condensation nucleation efficiencies were investigated under sub- and supersaturated relative humidity (RH) conditions using a hygroscopicity tandem differential mobility analyzer (H-TDMA) and a cloud condensation nuclei counter (CCNC), respectively. Experimental results show that both polymeric materials are slightly hygroscopic and that their single hygroscopicity parameter (κ) ranges from 0.03 to 0.25, which is within the κ range for secondary organic aerosols (SOA). Polycatechol is more hygroscopic than polyguaiacol, which is explained by differences in their structure. Polyguaiacol has similar water uptake as other insoluble organic compounds, and droplet formation is modelled well with Brunauer–Emmett–Teller (BET) or Frankel Hill Hershey-Adsorption Isotherm theory (FHH-AT). Both polymeric materials are not strongly surface active in range of 0.5 to 30 g L−1, and thus differences in subsaturated and supersaturated hygroscopicity measurement are not attributed to the presence of surface-active materials. Instead, it is due to the solubility limits of both chemicals and H-TDMA being driven by water adsorption. The implications of these results are discussed in the context of aerosol–cloud interactions from the hygroscopicity of aerosols from primary and secondary sources.