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    Item type:Publication, Access status: without files ,
    Isotopic fingerprints of proton-mediated dielectric relaxation in solid and liquid water
    (American Physical Society (APS), 2026-03-20)
    Ryzhov, Alexander
    ;
    Kapralov, Pavel
    ;
    Stolov, Mikhail
    ;
    Freger, Viatcheslav
    ;
    Andreev, Anton
    We report cross-validated measurements of the isotope effect on dielectric relaxation for four isotopologues of ice and water, including the 1–105 Hz region, in which only sporadic and inconsistent measurements were previously available. In ice, the relaxation rates exhibit an activated temperature dependence with an isotope-independent activation energy. Across 248–273 K, the H2O-to-D2O relaxation rate ratio remains constant at 2.0±0.1. This scaling agrees with Kramers’ theory in the high-friction limit if the moving mass is the proton or deuteron, indicating that dielectric relaxation is governed by a classic proton transfer over an energy barrier rather than molecular reorientation.
    Publicationtype: Journal Article
      47
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    Item type:Publication, Access status: with files ,
    Triboelectrification during non-wetting liquids intrusion–extrusion in hydrophobic nanoporous silicon monoliths
    (Elsevier, 2025-12-15)
    Bartolomé, Luis
    ;
    Verziaggi, Nicola
    ;
    Brinker, Manuel
    ;
    Amayuelas López Eder
    ;
    Merchiori, Sebastiano
    Triboelectric nanogenerators (TENGs) have emerged as promising devices for converting mechanical energy into electrical energy through contact electrification and electrostatic induction. However, the generated energy, unlike instantaneous power, current and voltage, is rarely addressed in the vibrant research field of TENGs. In this study, we investigate Intrusion–Extrusion Triboelectric Nanogenerators (IE-TENGs) based on nanoporous silicon monoliths and non-wetting liquids (i.e., water and a 1 mg/mL polyethylenimine solution), addressing the energy generated during this process, conversion efficiency as well as the mechanism underlying the observed phenomena. Compared to powder-based IE-TENGs, the use of monolithic silicon structures enables more efficient and reproducible energy harvesting, with significant improvements in both instantaneous power density and energy per cycle. We also analyzed the impact of compression rate and liquid properties on electrical output, showing that higher compression rates improve power generation, while modifying the liquid medium significantly improves conversion efficiency, reaching up to 9 %. Furthermore, through computational analysis, we identify the crucial role of grafting defects on the generated triboelectric output. This work introduces a novel approach to triboelectric energy harvesting by implementing a monolithic nanoporous architecture and offering an alternative pathway for enhancing contact electrification via confined solid–liquid interfaces. These findings provide new insights into the triboelectric behavior of porous systems and pave the way for next-generation high-performance IE-TENGs, with potential applications in wearable electronics, environmental energy harvesting, and self-powered sensing systems.
    Publicationtype: Journal Article
      38  64
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    Item type:Publication, Access status: without files ,
    Colossal effect of nanopore surface ionic charge on the dynamics of confined water
    (American Chemical Society (ACS), 2025-09-29)
    Mozhdehei, Armin
    ;
    Lenz, Philip
    ;
    Gries, Stella Inge Martha
    ;
    Meinert, Sophia Marie
    ;
    Lefort, Ronan
    Interfacial interactions significantly alter the fundamental properties of water confined in mesoporous structures with crucial implications for geological, physicochemical, and biological processes. Herein, we focused on the effect of changing the surface ionic charge of nanopores with comparable pore sizes (3.5–3.8 nm) on the dynamics of confined liquid water. The control of the pore surface ionicity was achieved by using two periodic mesoporous organosilicas (PMOs) containing either neutral or charged forms of a chemically similar bridging unit. The effect on the dynamics of water at the nanoscale was investigated in the temperature range 245–300 K, encompassing the glass transition by incoherent quasi-elastic neutron scattering (QENS). For both types of PMOs, the water dynamics revealed two distinct types of molecular motions: rapid local movements and translational jump diffusion. While the neutral PMO induces a moderate confinement effect, we show that the charged PMO drastically slows down water dynamics, reducing translational diffusion by a factor of 4 and increasing the residence time by an order of magnitude. Notably, by changing the pore filling values, we demonstrate that for charged PMOs, this effect extends beyond the interfacial layer of surface-bound water molecules to encompass the entire pore volume. Thus, our observation indicates a dramatic change in the long-range character of the interaction of water confined in nanopores with surface ionic charge compared to a simple change in hydrophilicity. This is relevant for the understanding of a broad variety of applications in (nano)technological phenomena and processes such as nanofiltration and membrane design.
    Publicationtype: Journal Article
      31