Amorphous silica-rich surface layers, also called gels, can passivate silicate glass and minerals depending on environmental conditions. However, several uncertainties remain on the mechanisms controlling the formation of these layers. In this paper, the influence of exogenous ions supplied by solutions is studied, both on the formation and on the properties of the gel formed on international simple glass (ISG). ISG was altered at 90 °C, pH_90 °C 7, in silica-saturated solutions containing various alkaline cations separately (Li⁺, Na⁺, K⁺, and Cs⁺). The alteration kinetics observed with Li and Na in the solution is similar to that observed with no ions, while K and Cs in the solution tend to decrease glass alteration. Furthermore, for K or Cs ions, the kinetics decreases as the ionic strength of the solution increases. The passivation layer formed in these solutions shows a selectivity toward cations following the series K > Cs > Na >> Li. These alkalis replace Ca from pristine glass in the altered structures, leading to differences in [AlO₄]⁻ units charge compensation. Importantly, exchange between Ca and alkali also affects the total quantity of water inside each gel and this effect is well correlated with the observed drop in glass alteration.

富含二氧化硅的无定形表面层，也称为凝胶，可以根据环境条件钝化硅酸盐玻璃和矿物质。但是，控制这些层形成的机制仍存在一些不确定性。在本文中，研究了溶液提供的外源离子对国际简单玻璃（ISG）上形成的凝胶的形成和性质的影响。ISG在90℃，pH值改变的_{90  ℃下}图7，在含有各种碱金属阳离子分开（栗二氧化硅-饱和溶液⁺，钠⁺，K ⁺，和Cs ⁺）。在溶液中用Li和Na观察到的变化动力学与在没有离子的情况下观察到的相似，而溶液中的K和Cs倾向于减少玻璃的变化。此外，对于K或Cs离子，动力学随着溶液离子强度的增加而降低。在这些溶液中形成的钝化层显示出对阳离子的选择性，遵循系列K> Cs> Na >> Li。这些碱替代了原始玻璃中改变结构的Ca，导致[AlO ₄ ] ^-单位电荷补偿的差异。重要的是，Ca和碱之间的交换也会影响每种凝胶内的水总量，并且这种效果与观察到的玻璃蚀变下降有很好的相关性。