Zhou Xiaoqi, Meng Zhisen, Picaud Sylvain, Devel Michel, Carrete Jesús, Madsen Georg K H, Zhou Yulu, Wang Zhao
Department of Physics, Guangxi University, Nanning 530004, China.
Institut UTINAM, CNRS UMR 6213, UBFC, 25030 Besançon, France.
ACS Omega. 2021 Oct 14;6(42):27898-27904. doi: 10.1021/acsomega.1c03571. eCollection 2021 Oct 26.
Molecular dynamics simulations are performed to characterize the nucleation behavior of organic compounds in the gas phase. Six basic molecular species are considered-ethylene, propylene, toluene, styrene, ethylbenzene, and -xylene-in interaction with onion-like carbon nanostructures that model soot nanoparticles (NPs) at room temperature. We identify a shell-to-island aggregation process during the physisorption of aromatic molecules on the soot surface: The molecules tend to first cover the NP in a shell, on top of which additional adsorbates form island-shaped aggregates. We present results for the binding energy, suggesting that the NPs lead to the formation of more stable molecular aggregates in comparison with the pure gas phase. Our findings describe a plausible microscopic mechanism for the active role of soot in the formation and growth of organic particulate matter.
进行分子动力学模拟以表征有机化合物在气相中的成核行为。考虑了六种基本分子种类——乙烯、丙烯、甲苯、苯乙烯、乙苯和二甲苯——在室温下与模拟烟灰纳米颗粒（NP）的洋葱状碳纳米结构相互作用。我们确定了芳香分子在烟灰表面物理吸附过程中的壳到岛的聚集过程：分子倾向于首先以壳的形式覆盖NP，在其之上额外的吸附质形成岛状聚集体。我们给出了结合能的结果，表明与纯气相相比，NP导致形成更稳定的分子聚集体。我们的发现描述了一个关于烟灰在有机颗粒物形成和生长中起积极作用的合理微观机制。
