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离子和带电粒子之间的相互作用受纳米/胶体颗粒表面上离子吸附控制,同时它决定着颗粒的微观性质、界面反应过程以及颗粒间相互作用。现有的离子界面反应理论没有考虑到离子特异性对离子-表面相互作用的影响。本研究建立了带电颗粒表面离子吸附模型。结果表明蒙脱石胶体表面离子吸附平衡存在着强烈的离子特异性效应。离子和表面之间的吸附能随离子浓度的增加而降低,随着粒子电荷密度(绝对值)升高而增加。根据建立的模型还可预测吸附反离子在扩散层中的位置,进而可计算出离子的吸附能与活化能。活化能直接决定了离子的吸附饱和度,且不同的离子遵循相同的规律。本研究表明建立的离子-表面相互作用模型在固/液界面反应中具有普适性的应用。
The interaction between ions and charged particles is controlled by ion adsorption on the surface of the nano / colloidal particles, and at the same time it determines the micro-properties of the particles, the interfacial reaction process and the interparticle interactions. Existing ion-interface reaction theory does not consider the effect of ion-specific ion-surface interaction. In this study, a model of ion adsorption on charged particle surface was established. The results show that there is a strong ion-specific effect on the ion adsorption equilibrium of montmorillonite colloids. The adsorption between the ions and the surface can decrease as the ion concentration increases, increasing as the charge density (absolute value) of the particles increases. According to the established model, the position of the adsorbed counter ions in the diffusion layer can also be predicted, and then the adsorption and activation energy of the ions can be calculated. Activation energy directly determines the adsorption of ions saturation, and different ions follow the same rules. This study shows that the established ion-surface interaction model has universal applicability in solid / liquid interface reactions.