Theory of the effect of stress on ultrasonic plane‐wave reflectivity from a water–metal interface

1979 ◽  
Vol 65 (6) ◽  
pp. 1380-1385 ◽  
Author(s):  
B. G. Martin
Keyword(s):  
Plane Wave ◽  
Metal Interface ◽  
Water Metal

Simulation of Ultrashort Laser Pulse Absorption At the Water-metal Interface in Laser-Induced Plasma Micro-Machining

2020 ◽  
Author(s):  
Jiaxi Xie ◽  
Kornel Ehmann ◽  
Jian Cao
Keyword(s):  
Dielectric Breakdown ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Optical Breakdown ◽  
Micro Machining ◽  
Metal Interface ◽  
Breakdown Threshold ◽  
Laser Induced Plasma ◽  
Water Metal ◽  
Ultrashort Laser

Abstract This work proposes a physically consistent numerical model to simulate ultrashort laser absorption by a metallic workpiece at the water-metal interface when optical breakdown of the dielectric occurs. The simulation couples the framework of the Finite-Difference Time-Domain method used in computational electromagnetics with the constitutive relation derived from both the model of direct ablation of metals and the first order model of water breakdown. The simulation is used to describe interface ablation processes such as Laser-Induced Plasma Micro-Machining. Applied to the water-aluminum interface, the model is able to describe the metal absorption and the dielectric breakdown threshold in three-dimensional geometry. It is an extensible monolithic approach in which the absorption by different materials can be described by simply changing the constitutive relations.

scholarly journals Structure, Dynamics, and Wettability of Water at Metal Interfaces

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Suji Gim ◽  
Kang Jin Cho ◽  
Hyung-Kyu Lim ◽  
Hyungjun Kim
Keyword(s):  
Surface Science ◽  
Metal Surfaces ◽  
Molecular Level ◽  
Contact Angles ◽  
Ambient Conditions ◽  
Metal Interface ◽  
Energy Applications ◽  
Structural Details ◽  
Water Metal ◽  
Metal Interfaces

Abstract The water/metal interface often governs important chemophysical processes in various technologies. Therefore, from scientific and engineering perspectives, the detailed molecular-level elucidation of the water/metal interface is of high priority, but the related research is limited. In experiments, the surface-science techniques, which can provide full structural details of the surface, are not easy to directly apply to the interfacial systems under ambient conditions, and the well-defined facets cannot be entirely free from contamination at the contact with water. To answer long-standing debates regarding the wettability, structure, and dynamics of water at metal interfaces, we here develop reliable first-principles-based multiscale simulations. Using the state-of-the-art simulations, we find that the clean metal surfaces are actually superhydrophilic and yield zero contact angles. Furthermore, we disclose an inadequacy of widespread ice-like bilayer model of the water adlayers on metal surfaces from both averaged structural and dynamic points of view. Our findings on the nature of water on metal surfaces provide new molecular level perspectives on the tuning and design of water/metal interfaces that are at the heart of many energy applications.

scholarly journals Diversity at the Water–Metal Interface: Metal, Water Thickness, and Confinement Effects

2016 ◽  
Vol 2 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Luca Bellarosa ◽  
Rodrigo García-Muelas ◽  
Guillem Revilla-López ◽  
Núria López
Keyword(s):  
Confinement Effects ◽  
Metal Interface ◽  
Water Metal ◽  
Metal Water

Vapor bubble induced electric current generation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenzhuo Li ◽  
Wanying Zhang ◽  
Lingye Zhou ◽  
Qingchen Shen ◽  
Modi Jiang ◽  
...  
Keyword(s):  
Electric Current ◽  
Heating Temperature ◽  
Thin Liquid Film ◽  
Electric Energy ◽  
Energy Output ◽  
Water Evaporation ◽  
Metal Interface ◽  
Current Output ◽  
Water Metal ◽  
The Impact

Abstract Contact electrification (CE) has been utilized in various energy conversion systems in recent years. This work presents a constant electric energy output that was generated based on the CE at the water–metal interface. When a grounded Pt mesh is placed in water that is heated to boil, a continuous flow of electrons between the Pt mesh and the ground is generated. A possible mechanism for the generation of such electric current is based on the CE between the surface of the Pt mesh and water molecules. The local high-pressure thin liquid film regions between vapor bubbles and surface of Pt mesh promote this CE process. The constant water evaporation and bubble detachment enable the continuous electric current output. In this work, the impact of the heating temperature and the bias voltages on the generation of the current was also studied. This work provides an alternative approach to generate unidirectional current on the basis of CE at the water–metal interface, and it also offers new insights in the design of CE-based systems for the generation of electricity.

scholarly journals Ten Facets, One Force Field: The GAL19 Force Field for Water - Noble Metal Interfaces

2020 ◽  
Author(s):  
Paul Clabaut ◽  
Paul Fleurat-Lessard ◽  
Carine Michel ◽  
Stephan Steinmann
Keyword(s):  
Force Field ◽  
Water Adsorption ◽  
Water Layer ◽  
Additive Functional ◽  
Accurate Estimation ◽  
Metal Interface ◽  
Representative Sampling ◽  
Water Metal ◽  
Adsorption Energies ◽  
Metal Interfaces

<div>Understanding the structure of the water/metal interfaces plays an important role in many are as ranging from surface chemistry to environmental processes. Due to their intrinsic complexity, the water/metal interfaces cannot yet be adequately described by quantum mechanical approaches and accurate force-fields are therefore needed. We develop and parametrize GAL19, a novel force-field to describe the interaction of water with two facets (111 and 100) of five metals (Pt, Pd, Au, Ag, Cu). To increase transferability compared to its predecessor GAL17, the water-metal interaction is described as a sum of pair-wise terms. The interaction energy has three contributions: (i) physisorption is described via a Tang and Toennies potential, (ii) chemisorption and surface corrugation relies on an attractive Gaussian term and (iii) the angular dependence is explicitly included as a truncated Fourier series. 13 parameters are used for each metal surface and were fitted on 250 water adsorption energies computed at the PBE+dDsC level. </div><div>The performance of GAL19 was evaluated on a set of more than 600 DFT adsorption energies for each surface, leading to an average root mean square deviation (RMSD) of only 1 kcal/mol, correctly reproducing the adsorption trends: strong on Pt and Pd but weaker on Ag, Au and Cu. This force-field was then used to simulate the water/metal interface for all ten surfaces for 1 ns. Structural analyses reveal similar tendencies for all surfaces: a first, dense water layer that is mostly adsorbed on the metal top sites, and a second layer up to around 6 Å, which is less structured. On Pt and Pd, the first layer is strongly organized with water lying flat on the surface. The pairwise additive functional form allows to simulate the water adsorption on alloys, which is demonstrated at the example of Ag/Cu and Au/Pt alloys. The water/Ag-Cu interface is predicted to be disordered with water mostly adsorbed on Cu which should exacerbate the Ag reactivity. On the contrary, incorporating Pt into Au materials leads to a structuring of the water interface. Our promising results make GAL19 an ideal candidate to get representative sampling of complex metal/water interfaces as a first step towards accurate estimation of free energies of reactions in solution at the metal interface.</div>

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