Understanding ion-ion interactions in bulk and aqueous interfaces using molecular simulations

• Published in: Faraday discussions Vol. 16; pp. 151 - 16
• Main Authors: Dang, Liem X, Sun, Xiuquan, Ginovska-Pangovska, Bojana, Annapureddy, Harsha V. R, Truong, Tai Ba
• Format: Journal Article
• Language: English
• Published: England 01.01.2013
• Subjects: Contact; Interfacial properties; Mathematical models; Reflectivity; Simulation; X-rays
• ISSN: 1359-6640; 1364-5498
• DOI: 10.1039/c2fd20093g

In addition to its scientific significance, the distribution of ions in the bulk and at aqueous interfaces is also very important for practical reasons. Providing a quantitative description of the ionic distribution, and describing interactions between ions in different environments, remains a challenge, and is the subject of current debate. In this study, we found that interionic potentials of mean force (PMFs) and interfacial properties are very sensitive to the ion-ion interaction potential models. Our study predicted a Sr 2+ -Cl − PMF with no contact ion-pair state and a shallow solvent-separated ion-pair state. In addition, we were able to quantitatively capture the experimental X-ray reflectivity results of the aqueous salt interface of the Sr 2+ -Cl − ion-pair, and provided a detailed physical description of the interfacial structure for this system. We also predicted the X-ray reflectivity results for SrBr 2 and SrI 2 systems.