Electrophoresis of core-shell structured cylindrical (nano)particles

This article presents a comprehensive study on the electrophoresis of cylindrical core-shell (nano)particles (NPs), where the inner core is coated with either a soft or semi-soft polyelectrolyte layer (PEL). The semi-soft PEL, characterized by a vanishing Brinkmann screening length, permits only electrolyte ion penetration, while the fluid flow within the soft PEL is regulated by a non-zero Brinkmann screening length. We examine particles with volumetric charges in both the core and shell, modeling the biological and environmental systems. The electrophoretic behavior of these infinitely long cylindrical colloids is investigated under electric fields applied perpendicular, parallel, and at arbitrary angles to the particle axis. Employing weak field and low charge approximations, we have derived the expressions for electrophoretic mobility of these nanoparticles. Our findings reveal notable phenomena, including zero mobility with non-zero charge density and non-zero mobility with zero net charge density. The results presented herein provide valuable insights for experimentalists seeking to accurately determine the intrinsic properties of core-shell structured NPs and environmental entities.