Alstadt Valerie J, Dawson Joseph Nelson, Losey Delanie J, Sihvonen Sarah K, Freedman Miriam Arak
Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
J Phys Chem A. 2017 Oct 26;121(42):8166-8175. doi: 10.1021/acs.jpca.7b06359. Epub 2017 Oct 13.
Heterogeneous ice nucleation is an important mechanism for cloud formation in the upper troposphere. Recently, pores on atmospheric particles have been proposed to play a significant role in ice nucleation. To understand how ice nucleation occurs in idealized pores, we characterized the immersion freezing activity of various sizes of carbon nanotubes. Carbon nanotubes are used both as a model for pores and proxy for soot particles. We determined that carbon nanotubes with inner diameters between 2 and 3 nm exhibit the highest ice nucleation activity. Implications for the freezing behavior of porous materials and nucleation on soot particles will be discussed.
非均相冰核化是对流层上层云形成的重要机制。最近，有人提出大气颗粒上的孔隙在冰核化过程中起着重要作用。为了了解理想化孔隙中冰核化是如何发生的，我们对各种尺寸的碳纳米管的浸入冻结活性进行了表征。碳纳米管既被用作孔隙的模型，也被用作烟尘颗粒的替代物。我们确定内径在2到3纳米之间的碳纳米管表现出最高的冰核化活性。将讨论对多孔材料冻结行为和烟尘颗粒成核的影响。
