Electrochemically Prepared Polymeric Precursors for the Formation of Non-Oxide Ceramics and Coatings

1992 ◽  
Vol 271 ◽  
Author(s):  
Ralph Zahneisen ◽  
Christian Rüssel
Keyword(s):  
Materials Science ◽  
Amorphous Solids ◽  
Metal Nitrides ◽  
Oxide Ceramics ◽  
Metal Carbides ◽  
Organic Amine ◽  
Subsequent Formation ◽  
Electrochemical Preparation ◽  
Polymeric Precursors ◽  
Oxide Powders

ABSTRACTThe electrochemical preparation of polymeric precursors and the subsequent formation of non-oxide powders, ceramics and coatings is described. The metals were anodically dissolved in an electrolyte consisting of a primary organic amine, acetonitrile as a solvent, and a tetraalkylammonium salt. This procedure led to the formation of polymeric precursor solutions. Removal of the excess organic compounds resulted in the formation of polymeric amorphous solids. Pyrolysis was carried out at temperatures in the range of 750 to 1100°C. In an atmosphere of ammonia, metal nitrides were formed, while calcination under nitrogen or argon led to carbonitrides or to carbides, depending on temperature and the metal used. Up to now, this route has been applied to Al, Ti, Zr, Cr, Ta, Mg, Ca and Y, and it is suppossed, that this route is applicable to the formation of many metal carbides and nearly all metal nitrides relevant for materials science.

scholarly journals Electronic properties and applications of MXenes: a theoretical review

2017 ◽  
Vol 5 (10) ◽  
pp. 2488-2503 ◽  
Author(s):  
Mohammad Khazaei ◽  
Ahmad Ranjbar ◽  
Masao Arai ◽  
Taizo Sasaki ◽  
Seiji Yunoki
Keyword(s):  
Transition Metal ◽  
Electronic Properties ◽  
Materials Science ◽  
Science And Technology ◽  
Max Phase ◽  
Two Dimensional ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Chemical Exfoliation

The recent chemical exfoliation of layered MAX phase compounds to novel two-dimensional transition metal carbides and nitrides, the so-called MXenes, has brought a new opportunity to materials science and technology.

scholarly journals 2D molybdenum and vanadium nitrides synthesized by ammoniation of 2D transition metal carbides (MXenes)

Nanoscale ◽  
2017 ◽  
Vol 9 (45) ◽  
pp. 17722-17730 ◽  
Author(s):  
Patrick Urbankowski ◽  
Babak Anasori ◽  
Kanit Hantanasirisakul ◽  
Long Yang ◽  
Lihua Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Elevated Temperatures ◽  
Metal Nitrides ◽  
Transition Metal Nitrides ◽  
Metal Carbides ◽  
Transition Metal Carbides ◽  
Vanadium Nitrides

Synthesis of 2D transition metal nitrides can be achieved by ammoniation of carbide MXenes (Mo2CTxand V2CTx) at elevated temperatures.

Syntheses of metal nitrides, metal carbides and rare-earth metal dioxymonocarbodiimides from metal oxides and dicyandiamide

2008 ◽  
Vol 460 (1-2) ◽  
pp. 130-137 ◽  
Author(s):  
M. Lei ◽  
H.Z. Zhao ◽  
H. Yang ◽  
B. Song ◽  
L.Z. Cao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Metal Oxides ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Metal Nitrides ◽  
Metal Carbides

Preceramic Inorganic Polymers

2005 ◽  
Author(s):  
James E. Mark ◽  
Harry R. Allcock ◽  
Robert West
Keyword(s):  
High Temperatures ◽  
Materials Science ◽  
Three Dimensional ◽  
Inert Atmosphere ◽  
Oxide Ceramics ◽  
Inorganic Polymers ◽  
Oxide Materials ◽  
Ceramic Fibers ◽  
The One ◽  
Powder Fusion

One of the most important interfaces in materials science is the one between polymers and ceramics. Ceramics can be viewed as highly cross-linked polymer systems, with the three-dimensional network providing strength, rigidity, and resistance to high temperatures. Although not generally recognized as such, a few ceramics exist that are totally organic (i.e., carbon-based). Melamine-formaldehyde resins, phenolformaldehyde materials, and carbon fibers are well-known examples. However, totally inorganic ceramics are more widely known, many of which are based on the elements silicon, aluminum, or boron combined with oxygen, carbon, or nitrogen. Among the inorganic ceramics, two different classes can be recognized—oxide ceramics and non-oxide materials. The oxide ceramics frequently include silicate structures, and these are relatively low melting materials. The non-oxide ceramics, such as silicon carbide, silicon nitride, aluminum nitride, and boron nitride are some of the highest melting substances known. Non-oxide ceramics are often so high melting that they are difficult to shape and fabricate by the melt- or powder-fusion techniques that are common for oxide materials. One major use for inorganic-organic polymers and oligomers is as sacrificial intermediates for pyrolytic conversion to ceramics. The logic is as follows. Linear, branched, or cyclolinear polymers or oligomers can be fabricated easily by solution- or melt-fabrication techniques. If a polymeric material that has been shaped and fabricated in this way is then cross-linked and pyrolyzed in an inert atmosphere to drive off the organic components (typically, the side groups), the resultant residue may be a totally inorganic ceramic in the shape of the original fabricated article. Thus, ceramic fibers, films, coatings, and shaped objects may by accessible without recourse to the ultra-high temperatures needed for melting of the ceramic material itself. Note, however, that although the final shape of the object may be retained during pyrolysis, the size will be diminished due to the loss of volatile material. If the pyrolysis takes place too quickly, this contraction process may cause cracking of the material and loss of strength.

Theory of Solid-State Defects

MRS Bulletin ◽  
1991 ◽  
Vol 16 (12) ◽  
pp. 22-26 ◽  
Author(s):  
A. M. Stoneham
Keyword(s):  
Materials Science ◽  
Amorphous Solids ◽  
Real Space ◽  
Electromagnetic Theory ◽  
Main Role ◽  
Band Theory ◽  
Materials Properties ◽  
Atomic Structures ◽  
Properties Of Materials ◽  
Interacting Atoms

Serious studies of materials are often serious studies of defects, for control of properties of materials implies control of defects or impurities. Understanding defect phenomena is crucial, and both theoretical ideas and modeling are enhancing key areas of materials properties and processing. I shall review some of the ways theory contributes. Theory enters into all aspects of materials science, even if you don't always realize you are using it.Even self-styled practical people, for whom theory is a luxury, use theory routinely in its first main role, as a framework for the data they lovingly collect. Elasticity theory, electromagnetic theory, and thermodynamics are normal tools for working engineers. The simplest ideas about electronic and atomic structures of solids are now so standard that one can forget their original impact, just as one forgets those within living memory who objected even to the idea of atoms. It was theory which gave clear guidelines for solids to be metals or insulators, when the real-space ideas of crystal structures based on interacting atoms were complemented by the reciprocal space notions from band theory. Such rules had been far from obvious. The behavior of amorphous solids has forced analogous theory-led upheavals in understanding.

scholarly journals A Recent Advance of Actinide Materials Science based on the Electrochemical Preparation of Uranium and Neptunium Metals

2007 ◽  
Vol 49 (11-12) ◽  
pp. 755-761
Author(s):  
Yoshinobu SHIOKAWA ◽  
Tomoo YAMAMURA ◽  
Dai AOKI ◽  
Yoshiya HOMMA ◽  
Yoshichika ŌNUKI
Keyword(s):  
Materials Science ◽  
Electrochemical Preparation

scholarly journals Predicting orientation-dependent plastic susceptibility from static structure in amorphous solids via deep learning

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhao Fan ◽  
Evan Ma
Keyword(s):  
Deep Learning ◽  
Mechanical Response ◽  
Materials Science ◽  
Learning Algorithm ◽  
Amorphous Solids ◽  
Valuable Insight ◽  
Structure Property ◽  
Three Dimensional Model ◽  
Static Structure ◽  
Structure Representation

AbstractIt has been a long-standing materials science challenge to establish structure-property relations in amorphous solids. Here we introduce a rotationally non-invariant local structure representation that enables different predictions for different loading orientations, which is found essential for high-fidelity prediction of the propensity for stress-driven shear transformations. This novel structure representation, when combined with convolutional neural network (CNN), a powerful deep learning algorithm, leads to unprecedented accuracy for identifying atoms with high propensity for shear transformations (i.e., plastic susceptibility), solely from the static structure in both two- and three-dimensional model glasses. The data-driven models trained on samples at one composition and a given processing history are found transferrable to glass samples with different processing histories or at different compositions in the same alloy system. Our analysis of the new structure representation also provides valuable insight into key atomic packing features that influence the local mechanical response and its anisotropy in glasses.

scholarly journals Recent Advance in the Fabrication of 2D and 3D Metal Carbides-Based Nanomaterials for Energy and Environmental Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 246
Author(s):  
Keming Wan ◽  
Yalin Li ◽  
Yan Wang ◽  
Gang Wei
Keyword(s):  
Environmental Science ◽  
Materials Science ◽  
2D Materials ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Environmental Applications ◽  
Synthesis Methods ◽  
Metal Carbides ◽  
New Family ◽  
2D And 3D

Two-dimensional (2D) nanomaterials have attracted increased interest and exhibited extended applications from nanotechnology to materials science, biomedicine, tissue engineering, as well as energy storage and environmental science. With the development of the synthesis and fabrication of 2D materials, a new family of 2D materials, metal carbides (MCs), revealed promising applications in recent years, and have been utilized for the fabrication of various functional 2D and three-dimensional (3D) nanomaterials for energy and environmental applications, ascribing to the unique physical and chemical properties of MCs. In this review, we present recent advance in the synthesis, fabrication, and applications of 2D and 3D MC-based nanomaterials. For this aim, we first summarize typical synthesis methods of MCs, and then demonstrate the progress on the fabrication of 2D and 3D MC-based nanomaterials. To the end, the applications of MC-based 2D and 3D materials for chemical batteries, supercapacitors, water splitting, photodegradation, removal of heavy metals, and electromagnetic shielding are introduced and discussed. This work provides useful information on the preparation, hybridization, structural tailoring, and applications of MC-based materials, and is expected to inspire the design and fabrication of novel and functional MXene materials with improved performance.

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