Determination of the collision rate coefficient between charged iodic acid clusters and iodic acid using the appearance time method
Determination of the collision rate coefficient between charged iodic acid clusters and iodic acid using the appearance time method
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DOI：
10.1080/02786826.2020.1839013
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发表时间：
2020-11-11
影响因子：
5.2
通讯作者：
Kulmala, Markku
中科院分区：
文献类型：
--
作者：
He, Xu-Cheng;Iyer, Siddharth;Kulmala, Markku
离子增强了大气气溶胶粒子的形成速度，而气溶胶粒子在地球辐射平衡中发挥着重要作用。离子诱导成核涉及中性单体逐步增生到含有离子的分子簇上，这有助于稳定簇以防止蒸发。虽然存在理论框架来计算中性分子和离子之间的碰撞速率系数，但它们需要实验证实，理想情况下是在大约1000个离子对cm（-3）的大气相关条件下。在这里，在大气条件下进行的实验中，在欧洲核子研究中心云室，我们已经测量了中性碘酸（HIO3）单体和带电的碘酸分子簇含有多达11个碘原子之间的碰撞速率系数。推导了计算离子与极性分子碰撞速率系数的三种方法。在用动力学模型评估后，发现50%出现时间方法是最稳健的。测得的碰撞速率系数为（2.4 +/-0.8）× 10（-9）cm（3）s（-1），与表面电荷俘获理论的预期值接近。
Ions enhance the formation rate of atmospheric aerosol particles, which play an important role in Earth's radiative balance. Ion-induced nucleation involves the stepwise accretion of neutral monomers onto a molecular cluster containing an ion, which helps to stabilize the cluster against evaporation. Although theoretical frameworks exist to calculate the collision rate coefficients between neutral molecules and ions, they need to be experimentally confirmed, ideally under atmospherically relevant conditions of around 1000 ion pairs cm(-3). Here, in experiments performed under atmospheric conditions in the CERN CLOUD chamber, we have measured the collision rate coefficients between neutral iodic acid (HIO3) monomers and charged iodic acid molecular clusters containing up to 11 iodine atoms. Three methods were analytically derived to calculate ion-polar molecule collision rate coefficients. After evaluation with a kinetic model, the 50% appearance time method is found to be the most robust. The measured collision rate coefficient, averaged over all iodine clusters, is (2.4 +/- 0.8)x10(-9 )cm(3) s(-1), which is close to the expectation from the surface charge capture theory.