Interpenetrating Networks of Three-Dimensional Penrose Tiles in CaAu3Ga, the Structurally Simplest Cubic Approximant of an Icosahedral Quasicrystal

2008 ◽  
Vol 47 (9) ◽  
pp. 3462-3464 ◽  
Author(s):  
Qisheng Lin ◽  
John D. Corbett
Keyword(s):  
Three Dimensional ◽  
Icosahedral Quasicrystal ◽  
Interpenetrating Networks ◽  
Penrose Tiles

Other topics

2018 ◽  
Author(s):  
Ted Janssen ◽  
Gervais Chapuis ◽  
Marc de Boissieu
Keyword(s):  
Photonic Crystals ◽  
Crystal Morphology ◽  
Three Dimensional ◽  
Icosahedral Quasicrystal ◽  
Crystal Surfaces ◽  
Decagonal Quasicrystal ◽  
System A ◽  
Fundamental Law ◽  
Quasiperiodic Systems ◽  
Aperiodic Crystals

The law of rational indices to describe crystal faces was one of the most fundamental law of crystallography and is strongly linked to the three-dimensional periodicity of solids. This chapter describes how this fundamental law has to be revised and generalized in order to include the structures of aperiodic crystals. The generalization consists in using for each face a number of integers, with the number corresponding to the rank of the structure, that is, the number of integer indices necessary to characterize each of the diffracted intensities generated by the aperiodic system. A series of examples including incommensurate multiferroics, icosahedral crystals, and decagonal quaiscrystals illustrates this topic. Aperiodicity is also encountered in surfaces where the same generalization can be applied. The chapter discusses aperiodic crystal morphology, including icosahedral quasicrystal morphology, decagonal quasicrystal morphology, and aperiodic crystal surfaces; magnetic quasiperiodic systems; aperiodic photonic crystals; mesoscopic quasicrystals, and the mineral calaverite.

scholarly journals Gold’s Structural Versatility within Complex Intermetallics: From Hume-Rothery to Zintl and even Quasicrystals

2013 ◽  
Vol 1517 ◽  
Author(s):  
Gordon J. Miller ◽  
Srinivasa Thimmaiah ◽  
Volodymyr Smetana ◽  
Andriy Palasyuk ◽  
Qisheng Lin
Keyword(s):  
Complex Networks ◽  
Intermetallic Compounds ◽  
Chemical Bonding ◽  
Three Dimensional ◽  
The Other ◽  
Icosahedral Quasicrystal ◽  
Bulk Solids ◽  
Atomic Properties ◽  
Polar Intermetallics ◽  
Structural Versatility

ABSTRACTRecent exploratory syntheses of polar intermetallic compounds containing gold have established gold’s tremendous ability to stabilize new phases with diverse and fascinating structural motifs. In particular, Au-rich polar intermetallics contain Au atoms condensed into tetrahedra and diamond-like three-dimensional frameworks. In Au-poor intermetallics, on the other hand, Au atoms tend to segregate, which maximizes the number of Au-heteroatom contacts. Lastly, among polar intermetallics with intermediate Au content, complex networks of icosahedra have emerged, including discovery of the first sodium-containing, Bergman-type, icosahedral quasicrystal. Gold’s behavior in this metal-rich chemistry arises from its various atomic properties, which influence the chemical bonding features of gold with its environment in intermetallic compounds. Thus, the structural versatility of gold and the accessibility of various Au fragments within intermetallics are opening new insights toward elucidating relationships among metal-rich clusters and bulk solids.

Modelling Stress Softening and Necking Phenomena in Double Network Hydrogels

2019 ◽  
Author(s):  
Vahid Morovati ◽  
Mohammad Ali Saadat ◽  
Roozbeh Dargazany
Keyword(s):  
Polymer Networks ◽  
Three Dimensional ◽  
Interpenetrating Polymer Networks ◽  
Biological Applications ◽  
Inelastic Behavior ◽  
Interpenetrating Networks ◽  
Double Network ◽  
Stress Softening ◽  
Proposed Model ◽  
Damage Process

Abstract Double network (DN) gels are three-dimensional polymer matrices formed by interpenetrating networks. In contrast to the conventional single-network gels, DN gels have significant toughness, which makes them a promising material for different biomedical and biological applications. However, DN gels show complicated inelastic behavior including the Mullins effect and necking instability. Despite extensive efforts on modelling different aspects of the damage process in gels, the micro-mechanical modelling of the mechanisms that lead to necking in DN gels remains to be a challenging task. Here, a constitutive model is proposed to understand and describe the mechanical behavior of DN gels based on statistical micro-mechanics of interpenetrating polymer networks. DN gels behavior is divided into three parts including pre-necking, necking, and hardening. The first network is dominant in the response of the gel in the pre-necking stage. The breakage of the first network to smaller network fractions (clusters) induces the stress softening observed in this stage. The interaction of both networks and the second network are also considered as main contributors to the response of gel in necking and hardening stages, respectively. The contribution of clusters decreases during the necking as the second network starts hardening. The numerical results of the proposed model are validated and compared by uni-axial cyclic tensile experimental data of DN gels.

Crystal Structures and Thermal Behavior of Alkaline Earth Tricyanomethanides

2008 ◽  
Vol 63 (3) ◽  
pp. 285-288 ◽  
Author(s):  
Karl E. Bessler ◽  
Claudia C. Gatto ◽  
Lincoln L. Romualdo ◽  
Javier A. Ellena ◽  
Maria J. de A. Sales
Keyword(s):  
Crystal Structure ◽  
Coordination Polymer ◽  
Thermal Behavior ◽  
Crystal Structures ◽  
Alkaline Earth ◽  
Three Dimensional ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Interpenetrating Networks ◽  
X Ray

The alkaline earth tricyanomethanides Mg(tcm)2 · 2H2O, Ca(tcm)2, Sr(tcm)2 ・H2O and Ba(tcm)2 · 2H2O were prepared from aqueous solutions of the respective chlorides and silver tricyanomethanide. Their IR spectra and thermal behavior are described. The crystal structures of Ca(tcm)2 and Ba(tcm)2 · 2H2O were determined by single crystal X-ray diffraction. The structure of Ca(tcm)2 is of the type found for several transition metal tricyanomethanides [1], containing two independent interpenetrating networks. Ba(tcm)2 · 2H2O has a unique crystal structure corresponding to a three-dimensional coordination polymer with nine fold coordinated Ba atoms connected by water molecules and tricyanomethanide anions.

scholarly journals On the indexing and reciprocal space of icosahedral quasicrystal

1999 ◽  
Vol 14 (11) ◽  
pp. 4182-4187 ◽  
Author(s):  
Alok Singh ◽  
S. Ranganathan
Keyword(s):  
Three Dimensional ◽  
Icosahedral Phase ◽  
Reciprocal Space ◽  
Fourth Generation ◽  
Icosahedral Quasicrystal ◽  
Sixth Generation

Important features of the icosahedral reciprocal space have been brought out. All reciprocal vectors up to sixth generation (by addition of icosahedral vectors) have been considered. Some more relationships for indexing the icosahedral phase are derived, and it is shown that the zone law using Cahn indices is also analogous to that valid for crystals. All important vectors, i.e., up to fourth generation and sixth generation, have been identified. Poles of all these vectors have been determined and shown to be one of the zone axes formed by these vectors. The types of indices that the planes and axes will have in three-dimensional and six-dimensional coordinates is discussed.

Study of sorption and diffusion in semi-interpenetrating networks based on three-dimensional polyurethane and a linear ionomer

1984 ◽  
Vol 26 (11) ◽  
pp. 2530-2539 ◽  
Author(s):  
Yu.S. Lipatov ◽  
L.V. Karabanova ◽  
L.M. Sergeyeva ◽  
E.Ya. Gorichko ◽  
S.I. Skiba
Keyword(s):  
Three Dimensional ◽  
Interpenetrating Networks ◽  
And Diffusion

scholarly journals CREATION A SORPTION MATERIAL FOR THE EXTRACTION OF METAL IONS FROM AQUEOUS SOLUTIONS

2021 ◽  
Vol 3 ◽  
pp. 97-107
Author(s):  
N.М. Zhunusbekova ◽  
◽  
Т.К. Iskakova ◽  
N.S. Chinibayeva ◽  
G.К. Kussainova ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Metal Ions ◽  
Polymer Composites ◽  
Contact Lenses ◽  
Specific Binding ◽  
Ion Pairs ◽  
Three Dimensional ◽  
Transition Metal Ions ◽  
Interpenetrating Networks ◽  
Soft Contact Lenses

The presence of a three-dimensional hydrophilic network structure ensures the uniqueness and wide practical application of hydrogels in industry, medicine, agriculture, etc. On their basis, soft contact lenses, dressings, superabsorbents, catalysts, soil structuring agents, preventing root drying and improving plant survival, have been created. The aimof this work is to synthesize new water-swellable polymer composites by combining monomer units of various natures based on acrylic acid and agar-agar with imidazole, differing in hydrophilic-hydrophobic balance. Results and discussion: The synthesis of new double and ternary polymer composites based on acrylic acid and agar-agar with imidazole was carried out, their physicochemical and complex-forming properties with transition metal ions in an aqueous medium were investigated. Comparative analysis showed that the complexation of interpenetrating networks with FeCl3 is more pronounced than with CoCl2. This fact can be associated with the difficulty of introducing a cobalt ion into the ligand plane during the formation of a metal complex, which further affects the binding to the functional groups of the network. The specific binding of the obtained polymer composites with metal salts was shown, which is carried out through the formation of ion pairs with the participation of counterions and coordination-unsaturated metals, which make the main contribution to the formation of extracomplexes and are responsible for the coordination of oxygen-containing ligands.

Four interpenetrating hydrogen-bonded three-dimensional networks in divanillin

2018 ◽  
Vol 74 (12) ◽  
pp. 1768-1773
Author(s):  
Marcos R. Imer ◽  
Virginia Aldabalde ◽  
Silvina Pagola ◽  
Jacco van de Streek ◽  
Leopoldo Suescun
Keyword(s):  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Interpenetrating Networks ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Translation Equivalent ◽  
Hydrogen Bonding Networks ◽  
Space Approach

The crystal structure of divainillin (systematic name: 6,6′-dihydroxy-5,5′-dimethoxy-[1,1′-biphenyl]-3,3′-dicarbaldehyde), C16H14O6, was determined from laboratory powder X-ray diffraction data using the software EXPO2013 (direct methods) and WinPSSP (direct-space approach). Divanillin molecules crystallize in the orthorhombic space group Pba2 (No. 32), with two molecules per unit cell (Z′ = 1 \over 2). Each divanillin molecule, with twofold symmetry, is linked through strong alcohol–aldehyde hydrogen bonds to four equivalent molecules, defining a three-dimensional hydrogen-bonding network, with rings made up of six divanillin units (a diamond-like arrangement). Each molecule is also connected through π–π interactions to a translation-equivalent molecule along c. Four consecutive molecules stacked along [001] belong to four different three-dimensional hydrogen-bonding networks defining a quadruple array of interpenetrating networks. This complex hydrogen-bonding array is proposed as an explanation for the aging process experienced by divanillin powders.

Intrinsic photonic wave localization in a three-dimensional icosahedral quasicrystal

2017 ◽  
Vol 13 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Seung-Yeol Jeon ◽  
Hyungho Kwon ◽  
Kahyun Hur
Keyword(s):  
Three Dimensional ◽  
Icosahedral Quasicrystal ◽  
Wave Localization
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