International Center for Quantum Materials, Peking University, No. 5 Yiheyuan Road, Haidian District, Beijing 100871, People's Republic of China.
Proc Natl Acad Sci U S A. 2012 Aug 14;109(33):13177-81. doi: 10.1073/pnas.1206879109. Epub 2012 Jul 25.
Adsorption of polar monomers on ice surface, relevant to the physical/chemical reaction in ice clouds as well as growth of ice, remains an open issue partially due to the unusual surface characteristics with protons at the top layer of ice. Using first-principle calculations, we explore the adsorption properties of ice surface in terms of a surface proton order parameter, which characterizes the inhomogeneity of the dangling atoms on ice surface. We show that, due to an effective electric field created by dangling OH bonds and lone pairs of water molecules not only directly neighboring but also further away from the adsorbed polar molecule on the ice surface, the adsorption energy of polar monomer on ice surface exhibits large variance and a strong correlation with the proton order parameter of ice surface. Our results about the positive correlation between the inhomogeneity of ice surface and adsorption energies suggest that the physical/chemical reactions as well as the growth of ice may prefer to occur firstly on surfaces with larger proton order parameter.
由于冰表面的特殊质子顶层结构，冰云中物理/化学反应以及冰的生长等相关的极性单体在冰表面的吸附问题仍然没有得到解决。本研究使用第一性原理计算，通过表面质子有序参数来研究冰表面的吸附特性，该参数可以描述冰表面悬挂原子的不均匀性。研究表明，由于悬挂 OH 键和水分子孤对产生的有效电场，不仅直接相邻而且离吸附在冰表面上的极性分子更远的水分子，极性单体在冰表面的吸附能具有很大的可变性，并且与冰表面的质子有序参数强烈相关。我们的研究结果表明，冰表面的不均匀性与吸附能之间存在正相关关系，这表明物理/化学过程以及冰的生长可能更倾向于首先在具有较大质子有序参数的表面上发生。
