Gong Haipeng, Freed Karl F
The James Franck Institute, University of Chicago, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2009 Feb 6;102(5):057603. doi: 10.1103/PhysRevLett.102.057603.
Ion-ion interactions are central to numerous phenomena in geology, biology, and material science, but current understanding is based on linear theories of limited physical applicability. Using the Langevin-Debye model, we investigate how nonlinear dielectric saturation alters screening of electrostatic interactions between solvated charges and show that charge screening in liquids strongly depends on the charge magnitudes but negligibly on the ion radii. Qualitatively different universal screening functions are predicted for ions with charges of the same or opposite signs.
离子-离子相互作用是地质、生物学和材料科学中众多现象的核心，但目前的认识是基于物理适用性有限的线性理论。我们使用朗之万-德拜模型，研究了非线性介电饱和如何改变溶剂化电荷之间静电相互作用的屏蔽，并表明液体中的电荷屏蔽强烈依赖于电荷大小，而对离子半径的依赖可忽略不计。对于具有相同或相反符号电荷的离子，预测了定性不同的通用屏蔽函数。
