Water–ion interaction in a nanoconfined environment that deeply constrains spatial freedoms of local atomistic motion with unconventional coupling mechanisms beyond that in a free, bulk state is essential to spark designs of a broad spectrum of nanofluidic devices with unique properties and functionalities. Here, it is reported that the interaction between ions and water molecules in a hydrophobic nanopore forms a coordination network with an interaction density that is nearly fourfold that of the bulk counterpart. Such strong interaction facilitates the connectivity of the water–ion network and is uncovered by corroborating the formation of ion clusters and the reduction of particle dynamics. A liquid‐nanopore energy‐dissipation system is designed and demonstrated in both molecular simulations and experiments that the formed coordination network controls the outflow of confined electrolytes along with a pressure reduction, capable of providing flexible protection for personnel and devices and instrumentations against external mechanical impact and attack.

Zr-4 alloy tubes, as the primary cladding material in nuclear reactor cores, face the critical challenge of oxidative attack in 1200 °C steam environments. To address this issue, high-temperature oxidation-resistant coatings fabricated via extreme high-speed laser cladding (EHLA) present a promising mitigation strategy. In this study, Y₂O₃-modified (0.0–5.0 wt.%) Cr/FeCrAl composite coatings were designed and fabricated on Zr-4 substrates using the EHLA process, followed by systematic investigation of Y doping effects on coating microstructures and steam oxidation resistance (1200 °C, H₂O atmosphere). Experimental results demonstrate that Y₂O₃ doping remarkably enhanced the oxidation resistance, with optimal performance achieved at 2.0 wt.% Y₂O₃ (31% oxidation mass gain compared to the substrate after 120-min exposure). Microstructural analysis reveals that the dense grain boundary network facilitates rapid surface diffusion of Al, promoting continuous Al₂O₃ protective film formation. Additionally, Y segregation at grain boundaries suppressed outward diffusion of Cr³⁺ cations, effectively inhibiting void formation at the oxide-coating interface and improving interfacial stability. The developed rare-earth-oxide-doped composite coating via extreme high-speed laser cladding process shows promising applications in surface-strengthening engineering for nuclear reactor Zr-4 alloy cladding tubes, providing both theoretical insights and technical references for the design of high-temperature oxidation-resistant coatings in nuclear industry.

Understanding liquid flow behavior in a nanoenvironment is of utmost importance for a vast array of biological and engineering applications. Both the liquid–solid interaction (LSI) and liquid–gas interaction (LGI) significantly affect the liquid outflow from hydrophobic nanopores in a liquid–gas–nanopore system. However, the individual contribution of these interactions on the spontaneous liquid outflow from the hydrophobic nanopores is not clear. To fill this scientific gap, we present an experimental study of the competition between the LSI and LGI on the nanoscale liquid outflow behavior in a liquid nanofoam (LN) system. LN samples, consisting of water and nanoporous silicas with similar pore size distribution but different average pore sizes, are subjected to cyclic pressure-induced liquid infiltration-outflow tests with or without the presence of a gas phase. Considerable difference in the liquid outflow behavior has been observed as pore size varies, indicating the size effect on the competition between the LSI and LGI. In smaller nanopores, the stronger LSI dominates the liquid outflow behavior as the LGI is diminished due to the nanoconfinement enhanced gas oversolubility. In contrast, in larger nanopores, LGI becomes a stronger driving force for the liquid outflow. These fundamental findings provide important insights on liquid flow behavior in a nanoenvironment and can facilitate a rational design of high performance nanofluidics-based systems.