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1. Analyzing ion uptake in ion-exchange membranes using ion association model

   https://doi.org/10.1016/j.memsci.2023.122202  

   Oren, Yaeli S; Nir, Oded; Freger, Viatcheslav (January 2024, Journal of Membrane Science)
2. Role of Ion Dehydration in Ion–Ion Selectivity of Dense Membranes

   https://doi.org/10.1021/acs.est.5c04303  

   Ershov, Alexander; Xu, Hengyu; Li, Ying; Tong, Tiezheng; Epsztein, Razi (August 2025, Environmental Science & Technology)

   Fabricating polymeric membranes with ion-specific selectivity has been targeted in recent years to address the growing challenges of water and resource scarcity. Inspired by discoveries of the selectivity mechanisms in biological channels, ion dehydration has been increasingly recognized as a key phenomenon governing the transport and selectivity in dense polymeric membranes and other synthetic nanochannels. However, understanding the molecular details of this phenomenon and leveraging and controlling it to increase the selectivity between ions in state-ofthe-art membranes remain elusive. In this Perspective, we discuss the foundations of ion dehydration and explore opportunities to study and leverage this phenomenon for improving ion−ion selectivity in membranes. We first introduce the fundamentals and measurements of ion’s hydration properties in solution, distinguishing between static and dynamic hydration properties. Next, we discuss simulation and experimental techniques to study ion dehydration under confinement, highlighting critical knowledge gaps that impede our understanding of this phenomenon. We then discuss effects of ion dehydration on the energy landscape of ion transport and analyze attempts in the literature to improve ion selectivity by promoting dehydration of specific ions. We conclude by proposing research directions to enhance our understanding of ion dehydration and fabricate sustainable and robust membranes with ion-specific selectivity. 

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3. Ion-Ion Interaction Induced Nondispersive Dynamics in an Electrostatic Ion Beam Trap

   https://doi.org/10.1103/PhysRevLett.131.225001  

   Sharma, Deepak; Heber, Oded; Zajfman, Daniel; Ringle, Ryan (November 2023, Physical Review Letters)
4. Electromagnetic ion cyclotron emission from ion-scale magnetic holes

   https://doi.org/10.1063/5.0205942  

   Shahid, Muhammad; Bashir, M Fraz; Artemyev, Anton V; Zhang, Xiao-Jia; Angelopoulos, Vassilis; Murtaza, G (July 2024, Physics of Plasmas)

   Ion-scale magnetic holes are nonlinear plasma structures commonly observed in the solar wind and Earth's magnetosphere. These holes are characterized by the magnetic field depletion filled by hot, transversely anisotropic ions and electrons and are likely formed during the nonlinear stage of ion mirror instability. Due to the plasma thermal anisotropy within magnetic holes, they serve as a host of electromagnetic ion cyclotron waves, whistler-mode waves, and electron cyclotron harmonic waves. This makes magnetic holes an important element of the Earth's inner magnetosphere, where electromagnetic waves generated within may strongly contribute to energetic ion and electron scattering. Such scattering, however, will modify the hot-ion distribution that is trapped within magnetic holes and responsible for the magnetic field stress balance. Therefore, hot ion scattering within magnetic holes likely determines the hole lifetime. In this study, we investigate how ion scattering by electromagnetic waves affects the stress balance and lifetime of magnetic holes. For illustration, we used typical characteristics of magnetic holes, ion populations, and ion cyclotron waves observed in the Earth's magnetosphere. We have demonstrated that ion distribution isotropization via scattering by waves does not change significantly magnetic hole magnitude, but ion losses due to scattering into the atmosphere may limit the hole life-times to 10–30 min in the Earth's inner magnetosphere. 

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5. The ion-ion correlations in organic ionic plastic crystal

   https://doi.org/10.20517/energymater.2024.209  

   Ahmed, Md Dipu; Martins, Murillo L; Abdullah, Mohanad; Singh, Harmandeep; Zheng, Allen; Greenbaum, Steven; Sokolov, Alexei P; Popov, Ivan (March 2025, Energy Materials)

   Organic ionic plastic crystals (OIPCs) are emerging as promising electrolyte materials for solid-state batteries. However, despite the fast ionic diffusion, OIPCs exhibit relatively low DC conductivity in solid phases caused by strong ion-ion correlations that suppress charge transport. To understand the origin of this suppression, we performed a study of ion dynamics in the OIPC 1-Ethyl-1-methylpyrrolidinium bis (trifluoromethyl sulfonyl) imide [P12][TFSI] utilizing dielectric spectroscopy, light scattering, and Nuclear Magnetic Resonance diffusometry. Comparison of the results obtained in this study with the published earlier results on an OIPC with a completely different structure (Diethyl(methyl)(isobutyl)phosphonium Hexafluorophosphate [P1,2,2,4][PF6]) revealed strong similarities in ion dynamics in both systems. Unlike DC conductivity, which may drop more than ten times between melted and solid phases, diffusion of anions and cations remains high and does not show strong changes at phase transition. The conductivity spectra in the broad frequency range demonstrate unusual shapes in solid phases with an additional step separating fast local ion motions from suppressed long-range charge diffusion controlling DC conductivity. We suggested that in solid phases, anions and cations can jump only between the specific ion sites defined by the crystalline structure. These constraints lead to strong cation-cation and anion-anion correlations strongly suppressing long-range charge transport. 

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