title: Electrokinetics of pH-regulated zwitterionic polyelectrolyte nanoparticles.
abstract: The electrokinetic behavior of pH-regulated, zwitterionic polyelectrolyte (PE) nanoparticles (NPs) in a general electrolyte solution containing multiple ionic species is investigated for the first time. The NPs considered are capable of simulating entities such as proteins, biomolecules, and synthetic polymers. The applicability of the model proposed is verified by the experimental data of succinoglycan nanoparticles available in the literature. We show that, in addition to their effective charge density, counterion condensation, double-layer polarization, and electro-osmotic flow of unbalanced counterions inside the double layer all significantly affect the electrophoretic behaviors of NPs. Our model successfully predicts many interesting electrophoretic behaviors, which qualitatively agree with experimental observations available in the literature. In contrast, because the effects of double-layer polarization and charge regulation are neglected, the existing theoretical models fail to explain the experimental results. The results gathered provide necessary information for the interpretation of relevant electrophoresis data in practice, and for nanofluidic applications such as biomimetic ion channels and nanopore-based sensing of single biomolecules.
authors.affiliation: Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan.
authors.forename: Li-Hsien
authors.initials: LH
authors.lastname: Yeh
authors.forename: Yi-Hsuan
authors.initials: YH
authors.lastname: Tai
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.forename: Jyh-Ping
authors.initials: JP
authors.lastname: Hsu
authors.forename: Shizhi
authors.initials: S
authors.lastname: Qian