Effects of salt concentration on the polyelectrolyte translocation through a cylinder nanopore

Publication date: Available online 1 November 2019Source: European Polymer JournalAuthor(s): Chang-Hui Wang, Meng-Bo Luo, Xiaojun Xu, Chao Wang, Li-Zhen SunAbstractThe salt concentration-dependent polyelectrolyte translocation through a cylinder nanopore is studied using Langevin dynamics simulation. We use the Debye-Hückel model combined with the generalized Born model to account for the salt-induced screening effect and the polarization effect for the polyelectrolyte charges. We prove the validity of our simulation model through the extensive simulation-experiment comparisons for the polyelectrolyte statistical size (the radius of gyration) at different salt bulk concentrations [s]. The simulation results show that the translocation time τ decreases with increasing [s]. At dilute [s], we find a power-law relation τ ~ [s]β with β < 0. The value of the exponent β is dependent on the driving force f but is insensitive to the polyelectrolyte length N. Moreover, we also study two important scaling relations τ ~ fδ (δ < 0) and τ ~ Nα (α > 0) at different [s]. With the increase of [s], the exponent δ increases and approaches to −1 at high [s], while the exponent α is independent of the salt concentration no matter whether in the quasi-equilibrium state (α = 1.07) or in the non-equilibrium state (α = 1.35).Graphical abstract
Source: European Polymer Journal - Category: Chemistry Source Type: research