J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague, Czech Republic.
J Chem Phys. 2012 Jul 21;137(3):034304. doi: 10.1063/1.4733987.
Uptake of several atmospheric molecules on free ice nanoparticles was investigated. Typical examples were chosen: water, methane, NO(x) species (NO, NO(2)), hydrogen halides (HCl, HBr), and volatile organic compounds (CH(3)OH, CH(3)CH(2)OH). The cross sections for pickup of these molecules on ice nanoparticles (H(2)O)(N) with the mean size of N≈260 (diameter ~2.3 nm) were measured in a molecular beam experiment. These cross sections were determined from the cluster beam velocity decrease due to the momentum transfer during the pickup process. For water molecules molecular dynamics simulations were performed to learn the details of the pickup process. The experimental results for water are in good agreement with the simulations. The pickup cross sections of ice particles of several nanometers in diameter can be more than 3 times larger than the geometrical cross sections of these particles. This can have significant consequences in modelling of atmospheric ice nanoparticles, e.g., their growth.
研究了几种大气分子在自由冰纳米粒子上的吸收情况。选择了典型的例子：水、甲烷、NO(x) 物种（NO、NO(2)）、氢卤化物（HCl、HBr）和挥发性有机化合物（CH(3)OH、CH(3)CH(2)OH）。在分子束实验中测量了这些分子在平均大小为 N≈260（直径~2.3nm）的冰纳米粒子（H(2)O）(N)上的吸收截面。这些截面是通过团簇束速度由于在吸收过程中动量传递而降低来确定的。对于水分子，进行了分子动力学模拟以了解吸收过程的细节。水的实验结果与模拟结果吻合良好。直径数纳米的冰粒子的吸收截面可以比这些粒子的几何截面大 3 倍以上。这在大气冰纳米粒子的建模中可能会产生重大影响，例如它们的生长。
