论文标题
与水解物接触的电介质表面充电 - CO $ _2 $的影响
Charging of dielectric surfaces in contact with aqueous electrolyte -- the influence of CO$_2$
论文作者
论文摘要
水性环境中介电表面的电荷状态具有基本和技术重要性。在这里，我们研究了溶解的分子co $ _2 $对三个化学上不同表面的充电（Sio $ _2 $，聚苯乙烯，全氟二甲苯二甲苯甲烷）的影响。我们通过电动实验确定它们的电荷状态。我们将理想的，$ _2 $的参考系统与针对环境CO $ _2 $条件平衡的系统进行了比较。在参考系统中，SIO $ _2 $的盐依赖性被削弱，并在有机表面倒置。我们表明，仅筛查和pH驱动的电荷调节无法解释观察到的效果。作为其他原因，我们暂时建议由于分子CO $ _2 $的扩散吸附的薄层而引起的表面电荷的介电调节。即使在亲水性和部分离子化的二氧化硅表面上，这种动态层的形成也受到最小的理论模型的支持，并由分子模拟产生。
The charge state of dielectric surfaces in aqueous environments is of fundamental and technological importance. Here, we study the influence of dissolved molecular CO$_2$ on the charging of three, chemically different surfaces (SiO$_2$, Polystyrene, Perfluorooctadecyltrichlorosilane). We determine their charge state from electrokinetic experiments. We compare an ideal, CO$_2$-free reference system to a system equilibrated against ambient CO$_2$ conditions. In the reference system, the salt-dependence is weakened for SiO$_2$ and inverted for the organic surfaces. We show that screening and pH-driven charge regulation alone cannot explain the observed effects. As additional cause, we tentatively suggest dielectric regulation of surface charges due to a diffusively adsorbed thin layer of molecular CO$_2$. The formation of such a dynamic layer even at the hydrophilic and partially ionized silica surfaces is supported by a minimal theoretical model and results from molecular simulations.
