Special Issue "Nanoporous Metallic Alloys"

A special issue of Metals (ISSN 2075-4701).

Deadline for manuscript submissions: closed (30 June 2015)

Special Issue Editors

Guest Editor
Dr. Eva Pellicer

Ramon y Cajal Researcher, Gnm3 group, Physics Department, Cc (C3/210) building, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
Website | E-Mail
Interests: electrodeposition; metallic micro- and nanostructures; ordered mesoporous metal oxides; nanocasting; magnetic properties; electrocatalytic properties
Guest Editor
Prof. Dr. Jordi Sort

1 Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain
2 Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluís Companys 23, E-08010 Barcelona, Spain
Website | E-Mail
Phone: +34 93 581 2085
Fax: +34 93 581 2155
Interests: metallic alloys; composite materials; nanomaterials; biomaterials; thin films; nanoporous materials; surface treatments; mechanical performance; magnetism

Special Issue Information

Dear Colleagues,

Nanoporous metallic alloys exhibit a wealth of intriguing properties compared to bulk fully-dense materials. Their ultra-high surface area−to−volume ratio, together with their low density and the possibility of hosting second-phase materials inside the porous frameworks, make these alloys useful for widespread technological applications that range from catalysts, filters, fuel cells or batteries to sophisticated platforms for drug delivery or biological labeling. The mechanical properties of these alloys (high elastic recovery, low Young’s modulus, ultra-high yield strain) foster additional functionalities for these materials, such as orthopedic implants with optimum biomechanical compatibility or nanoporous impact damper coatings with enhanced shock-resistance. This Special Issue welcomes contributions dealing with innovative strategies for synthesizing macro- (pore size > 50 nm), meso- (2 nm < pore size < 50 nm) and microporous (pore size < 2 nm) metallic alloys, such as via electrodeposition (by colloidal crystal and block-copolymer templating or by using hydrogen bubbling as a dynamic source of porosity), de-alloying, and sol-gel or nanosmelting (amongst others). Special emphases will be given to studies focusing on the control of the pore architecture, pore size distribution, and composition of the synthesized materials. Furthermore, experimental and theoretical reports that shed light on the interesting features of nanoporous metallic systems and their applications, as well as on advanced and innovative techniques for fully characterizing these type of materials, also fall within the scope of this Special Issue.

Dr. Eva Pellicer
Prof. Dr. Jordi Sort
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Metals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • nanoporous alloys
  • metallic foams
  • metallic aerogels
  • porosity

Published Papers (3 papers)

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Research

Open AccessArticle Mechanical Properties of Nanoporous Au: From Empirical Evidence to Phenomenological Modeling
Metals 2015, 5(3), 1665-1694; doi:10.3390/met5031665
Received: 30 June 2015 / Revised: 5 September 2015 / Accepted: 8 September 2015 / Published: 16 September 2015
Cited by 2 | PDF Full-text (1754 KB) | HTML Full-text | XML Full-text
Abstract
The present work focuses on the development of a theoretical model aimed at relating the mechanical properties of nanoporous metals to the bending response of thick ligaments. The model describes the structure of nanoporous metal foams in terms of an idealized regular lattice
[...] Read more.
The present work focuses on the development of a theoretical model aimed at relating the mechanical properties of nanoporous metals to the bending response of thick ligaments. The model describes the structure of nanoporous metal foams in terms of an idealized regular lattice of massive cubic nodes and thick ligaments with square cross-sections. Following a general introduction to the subject, model predictions are compared with Young’s modulus and the yield strength of nanoporous Au foams determined experimentally and available in literature. It is shown that the model provides a quantitative description of the elastic and plastic deformation behavior of nanoporous metals, reproducing to a satisfactory extent the experimental Young’s modulus and yield strength values of nanoporous Au. Full article
(This article belongs to the Special Issue Nanoporous Metallic Alloys)
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Open AccessArticle Thermal Stability of Nanoporous Raney Gold Catalyst
Metals 2015, 5(3), 1197-1211; doi:10.3390/met5031197
Received: 17 June 2015 / Revised: 27 June 2015 / Accepted: 1 July 2015 / Published: 7 July 2015
Cited by 3 | PDF Full-text (1175 KB) | HTML Full-text | XML Full-text
Abstract
Nanoporous “Raney gold” sponge was prepared by de-alloying an Au-Al precursor alloy. Catalytic tests using a micro-reactor confirmed that Raney gold can serve as an active heterogeneous catalyst for CO oxidation, reduction of NO to N2, and oxidation of NO to
[...] Read more.
Nanoporous “Raney gold” sponge was prepared by de-alloying an Au-Al precursor alloy. Catalytic tests using a micro-reactor confirmed that Raney gold can serve as an active heterogeneous catalyst for CO oxidation, reduction of NO to N2, and oxidation of NO to NO2. In general, the specific surface area of a heterogeneous catalyst has an influence on its catalytic efficacy. Unfortunately, gold sponges coarsen readily, leading to sintering of their structure and reduction in surface area. This potentially places constraints on their upper operating temperature in catalytic reactors. Here we analyzed the behavior of Raney gold when the temperature was raised. We examined the kinetics and mechanism of coarsening of the sponge using a combination of in situ optical measurements and Metropolis Monte Carlo modeling with a Lennard-Jones interatomic potential. Modeling showed that the sponges started with an isotropic “foamy” morphology with negative average “mean curvature” but that subsequent thermally activated coarsening will drive the morphology through a bi-continuous fibrous state and on, eventually, to a sponge consisting of sintered blobs of predominantly positive “mean curvature”. Full article
(This article belongs to the Special Issue Nanoporous Metallic Alloys)
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Open AccessArticle Measurement and Determination of Friction Characteristic of Air Flow through Porous Media
Metals 2015, 5(1), 336-349; doi:10.3390/met5010336
Received: 8 January 2015 / Revised: 10 February 2015 / Accepted: 2 March 2015 / Published: 9 March 2015
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Abstract
Sintered metal porous media currently plays an important role in air bearing systems. When flowing through porous media, the flow properties are generally represented by incompressible Darcy-Forchheimer regime or Ergun regime. In this study, a modified Ergun equation, which includes air compressibility effects,
[...] Read more.
Sintered metal porous media currently plays an important role in air bearing systems. When flowing through porous media, the flow properties are generally represented by incompressible Darcy-Forchheimer regime or Ergun regime. In this study, a modified Ergun equation, which includes air compressibility effects, is developed to describe friction characteristic. Experimental and theoretical investigations on friction characteristic are conducted with a series of metal-sintered porous media. Re = 10 is selected as the boundary for a viscous drag region and a form drag region. Experimental data are first used to determine the coefficient α in the viscous drag region, and then the coefficient β in the form drag region, rather than both simultaneously. Also, the theoretical mass flow rate in terms of the modified Ergun equation provides close approximations to the experimental data. Finally, it is also known that both the air compressibility and inertial effects can obviously enhance the pressure drop. Full article
(This article belongs to the Special Issue Nanoporous Metallic Alloys)

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Fe80Ga20 nanowire preparation at various pore diameters
Authors:
Diana Pohl, Heike Schlörb
Affiliation:
IFW Dresden, Leibniz Institute for Solid State and Materials Research Dresden, 01171 Dresden, Germany
Abstract:
Fe80Ga20 alloy thin films are electrochemically accessible from a simple aqueous electrolyte. In order to reduce the dimensionality of the alloy films large arrays of nanowires were deposited within nanoporous templates. It has been shown that, for sub-micrometer pore diameters, the simple electrolyte is suitable to completely fill the pores and to produce metallic nanowires whereas at pore diameters below 100 nm the restricted transport properties in the narrow pore geometry inhibit the growth of continuous nanowires. The extended hydrogen evolution produces large amounts of hydroxides that cannot be completely redissolved and removed from the high aspect ratio nanopores therefore leading to discontinuous nanowires. By modifying the electrolyte the hydroxide formation and incorporation can be prevented resulting in continuous metallic alloy nanowires of several micrometer length even at pore diameters far below 100 nm.
Keywords:
template based electrodeposition; nanowire array; Fe80Ga20

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