title: Potential of mean force between like-charged nanoparticles: Many-body effect.
abstract: Ion-mediated interaction is important for the properties of polyelectrolytes such as colloids and nucleic acids. The effective pair interactions between two polyelectrolytes have been investigated extensively, but the many-body effect for multiple polyelectrolytes still remains elusive. In this work, the many-body effect in potential of mean force (PMF) between like-charged nanoparticles in various salt solutions has been comprehensively examined by Monte Carlo simulation and the nonlinear Poisson-Boltzmann theory. Our calculations show that, at high 1:1 salt, the PMF is weakly repulsive and appears additive, while at low 1:1 salt, the additive assumption overestimates the repulsive many-body PMF. At low 2:2 salt, the pair PMF appears weakly repulsive while the many-body PMF can become attractive. In contrast, at high 2:2 salt, the pair PMF is apparently attractive while the many-body effect can cause a weaker attractive PMF than that from the additive assumption. Our microscopic analyses suggest that the elusive many-body effect is attributed to ion-binding which is sensitive to ion concentration, ion valence, number of nanoparticles and charges on nanoparticles.
authors.affiliation: Center for Theoretical Physics and Key Laboratory of Artificial Micro &Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center for Theoretical Physics and Key Laboratory of Artificial Micro &Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
authors.forename: Jin-Si
authors.initials: JS
authors.lastname: Zhang
authors.affiliation: Center for Theoretical Physics and Key Laboratory of Artificial Micro &Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
authors.forename: Ya-Zhou
authors.initials: YZ
authors.lastname: Shi
authors.affiliation: Department of Physics, School of Physics &Information Engineering, Jianghan University, Wuhan 430056, China.
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Zhu
authors.affiliation: Center for Theoretical Physics and Key Laboratory of Artificial Micro &Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072, China.
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Tan