Butreddy Pravalika, Heo Jaeyoung, Rampal Nikhil, Liu Tingting, Liu Lili, Smith William, Zhang Xin, Prange Micah P, Legg Benjamin A, Schenter Gregory K, De Yoreo James J, Chun Jaehun, Stack Andrew G, Nakouzi Elias
Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.
Material Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States.
ACS Nano. 2024 Sep 12. doi: 10.1021/acsnano.4c05563.
The connection between solution structure, particle forces, and emergent phenomena at solid-liquid interfaces remains ambiguous. In this case study on boehmite aggregation, we established a connection between interfacial solution structure, emerging hydration forces between two approaching particles, and the resulting structure and kinetics of particle aggregation. In contrast to expectations from continuum-based theories, we observed a nonmonotonic dependence of the aggregation rate on the concentration of sodium chloride, nitrate, or nitrite, decreasing by 15-fold in 4 molal compared to 1 molal solutions. These results are accompanied by an increase in repulsive hydration forces and interfacial oscillatory features from 0.27-0.31 nm in 0.01 molal to 0.38-0.52 nm in 2 molal. Moreover, molecular dynamics (MD) simulations indicated that these changes correspond to enhanced ion correlations near the interface and produced loosely bound aggregates that retain electrolyte between the particles. We anticipate that these results will enable the prediction of particle aggregation, attachment, and assembly, with broad relevance to interfacial phenomena.
固液界面处溶液结构、颗粒作用力和涌现现象之间的联系仍不明确。在本次关于勃姆石聚集的案例研究中，我们建立了界面溶液结构、两个接近颗粒之间出现的水化力以及由此产生的颗粒聚集结构和动力学之间的联系。与基于连续介质理论的预期相反，我们观察到聚集速率对氯化钠、硝酸盐或亚硝酸盐浓度呈非单调依赖性，与1摩尔溶液相比，在4摩尔溶液中聚集速率降低了15倍。这些结果伴随着排斥性水化力的增加以及界面振荡特征从0.01摩尔溶液中的0.27 - 0.31纳米增加到2摩尔溶液中的0.38 - 0.52纳米。此外，分子动力学（MD）模拟表明，这些变化对应于界面附近增强的离子相关性，并产生了在颗粒之间保留电解质的松散结合聚集体。我们预计这些结果将有助于预测颗粒的聚集、附着和组装，与界面现象广泛相关。
