Reversible strain by physisorption in nanoporous gold

Detsi, Eric; Chen, Z. G.; Vellinga, WP Willem Pier; Onck, Patrick; Hosson, de Jeff

doi:10.1063/1.3625926

Cited by 54 publications

(32 citation statements)

References 19 publications

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“…The porosity of the alloy is determined from the base chemistry of the precursor alloy, while the ligament size (or pore size) is controlled by the de-alloying conditions (such as rate) and any subsequent annealing to coarsen the structure [5]. Nanoporous metals have been noted as viable candidates for materials in catalysts [6][7][8] and sensors and actuators [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

The mechanical response of core-shell structures for nanoporous metallic materials

Abdolrahim

Bahr

Revard

et al. 2013

Philosophical Magazine

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Nanoporous gold (NP-Au) exhibits microscale plasticity, but macroscopically fails in a relatively brittle manner. This current study suggests that a core-shell structure can increase both ductility and strength of NP-Au. A core Au foam structure was created using conventional dealloying methods with average ligament size of 60 nm. Nickel was then electroplated on to the NPAu with layer thicknesses ranging from 2.5 nm to 25 nm. Nanoindentation demonstrated a significant increase in the hardness of the coated Np-Au, to about five times of that of the pure Np-Au, and a decrease in creep by increasing the thickness of the coated Ni layer. Molecular dynamics simulations of Au-Ni ligaments show the same trend of strengthening behavior with increasing Ni thickness suggesting that the strengthening mechanisms of the Np-Au are comparable to those for fcc nano ligaments. The simulations demonstrate two different strengthening mechanisms with the increased activity of the twins in plated Au-Ni ligaments, which leads to more ductile behavior, as opposing to the monolithic Au ligaments where nucleation of dislocations govern the plasticity during loading.

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Section: Introductionmentioning

confidence: 99%

The mechanical response of core-shell structures for nanoporous metallic materials

Abdolrahim

Bahr

Revard

et al. 2013

Philosophical Magazine

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“…Nanoporous gold (NPG) made by dealloying has attracted much attention due to its prospective applications in, e.g., actuation [1][2][3][4][5][6], catalysis [7,8], sensing [9,10], and microfluidics [11]. The material represents a network of short fibers or 'ligaments' with dimensions that can be controlled between 5 nm and several micrometers [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Anomalous compliance and early yielding of nanoporous gold

Ngô

Stukowski

Mameka³

et al. 2015

Acta Materialia

117

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We present a study of the elastic and plastic behavior of nanoporous gold in compression, focusing on molecular dynamics simulation and inspecting experimental data for verification. Both approaches agree on an anomalously high elastic compliance in the early stages of deformation, along with a quasi immediate onset of plastic yielding even at the smallest load. Already before the first loading, the material undergoes spontaneous plastic deformation under the action of the capillary forces, requiring no external load. Plastic deformation under compressive load is accompanied by dislocation storage and dislocation interaction, along with strong strain hardening. Dislocation-starvation scenarios are not supported by our results. The stiffness increases during deformation, but never approaches the prediction by the relevant Gibson-Ashby scaling law. Microstructural disorder affects the plastic deformation behavior and surface excess elasticity might modify elastic response, yet we relate the anomalous compliance and the immediate yield onset to an atomistic origin: the large surface-induced prestress induces elastic shear that brings some regions in the material close to the shear instability of the generalized stacking fault energy curve. These regions are elastically highly compliant and plastically weak.

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“…The contribution for this Golden Jubilee issue of the Journal of Materials Science will be focused on the actuating properties of metallic foams, although these materials turned out be also sensors [36,37]. In the Discussion section, we also present an outlook onto two promising energy-related fields, involving oxygen evolution and Liion battery, in which porous metals may have a large impact.…”

Section: Introductionmentioning

confidence: 99%

Metallic muscles and beyond: nanofoams at work

Detsi

Tolbert²,

Punzhin

et al. 2015

J Mater Sci

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In this contribution for the Golden Jubilee issue commemorating the 50th anniversary of the Journal of Materials Science, we will discuss the challenges and opportunities of nanoporous metals and their composites as novel energy conversion materials. In particular, we will concentrate on electrical-to-mechanical energy conversion using nanoporous metal-polymer composite materials. A materials system that mimic the properties of human skeletal muscles upon an outside stimulus is coined an 'artificial muscle.' In contrast to piezoceramics, nanoporous metallic materials offer a unique combination of low operating voltages, relatively large strain amplitudes, high stiffness, and strength. Here we will discuss smart materials where large macroscopic strain amplitudes up to 10 % and strain-rates up to 10 -2 s -1 can be achieved in nanoporous metal/polymer composite. These strain amplitudes and strain-rates are roughly 2 and 5 orders of magnitude larger than those achieved in common actuator materials, respectively. Continuing on the theme of energy-related applications, in the summary and outlook, we discuss two recent developments toward the integration of nanoporous metals into energy conversion and storage systems. We specifically focus on the exciting potential of nanoporous metals as anodes for high-performance water electrolyzers and in next-generation lithium-ion batteries.

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Reversible strain by physisorption in nanoporous gold

Cited by 54 publications

References 19 publications

The mechanical response of core-shell structures for nanoporous metallic materials

The mechanical response of core-shell structures for nanoporous metallic materials

Anomalous compliance and early yielding of nanoporous gold

Metallic muscles and beyond: nanofoams at work

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