Structural and Physical Properties in the Bi‐Sr‐Cu‐O System

1989 ◽  
Vol 169 ◽  
Author(s):  
S. A. Sunshine ◽  
L. F. Schneemeyer ◽  
R. M. Fleming ◽  
A. T. Fiory ◽  
S. Martin ◽  
...  
Keyword(s):  
Solid Solution ◽  
Physical Properties ◽  
Structural Model ◽  
Structure Property ◽  
Structure Property Relationships

AbstractThe structure/property relationships in the Bi‐Sr‐Cu‐O system near Bi2Sr2CuOx have been investigated. The properties and phase limits of the solid solution Bi2+xSr2_yCuO6±δ have been determined and a structural model for Bi2Sr2CuO6 is proposed.

scholarly journals Predicting permeability via statistical learning on higher-order microstructural information

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Magnus Röding ◽  
Zheng Ma ◽  
Salvatore Torquato
Keyword(s):  
Neural Networks ◽  
Physical Properties ◽  
Specific Surface ◽  
Correlation Functions ◽  
Quantitative Structure ◽  
Structure Property ◽  
Complex Materials ◽  
Structure Property Relationships ◽  
Quantitative Structure Property Relationships ◽  
Point Correlation

Abstract Quantitative structure–property relationships are crucial for the understanding and prediction of the physical properties of complex materials. For fluid flow in porous materials, characterizing the geometry of the pore microstructure facilitates prediction of permeability, a key property that has been extensively studied in material science, geophysics and chemical engineering. In this work, we study the predictability of different structural descriptors via both linear regressions and neural networks. A large data set of 30,000 virtual, porous microstructures of different types, including both granular and continuous solid phases, is created for this end. We compute permeabilities of these structures using the lattice Boltzmann method, and characterize the pore space geometry using one-point correlation functions (porosity, specific surface), two-point surface-surface, surface-void, and void-void correlation functions, as well as the geodesic tortuosity as an implicit descriptor. Then, we study the prediction of the permeability using different combinations of these descriptors. We obtain significant improvements of performance when compared to a Kozeny-Carman regression with only lowest-order descriptors (porosity and specific surface). We find that combining all three two-point correlation functions and tortuosity provides the best prediction of permeability, with the void-void correlation function being the most informative individual descriptor. Moreover, the combination of porosity, specific surface, and geodesic tortuosity provides very good predictive performance. This shows that higher-order correlation functions are extremely useful for forming a general model for predicting physical properties of complex materials. Additionally, our results suggest that artificial neural networks are superior to the more conventional regression methods for establishing quantitative structure–property relationships. We make the data and code used publicly available to facilitate further development of permeability prediction methods.

Investigation of the Structure-Property Relationships of Improved Low Compression Set Nitrile Rubbers

1981 ◽  
Vol 54 (1) ◽  
pp. 170-180 ◽  
Author(s):  
D. M. Chang
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Structure And Properties ◽  
Structure Property ◽  
Compression Set ◽  
Structure Property Relationships ◽  
Polymer Properties ◽  
Nitrile Rubbers ◽  
New Type ◽  
The Right

Abstract The effect of polymer structures on the rubber processing and physical properties of the improved Hycar 1090 low compression set nitrile rubbers was investigated. The molecular weight and acrylonitrile content of a polymer are important variables in determining the compound processing and vulcanizate physical properties. Within the range of 21 to 88 Mooney, a blend of high and low Mooney polymers has approximately the same properties as those from a single polymer of the same Mooney viscosity. The molecular weight distribution was not significantly broadened to become an important factor affecting the polymer properties. All polymers with Mooney viscosities from 21 to 88 showed good properties. An understanding of the structure and properties of this new type of NBR, will help in choosing the right kind of polymer for particular applications.

scholarly journals Heterometal Grafted metalla-ynes and Poly(metalla-ynes): A Review on Structure–Property Relationships and Applications

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3654
Author(s):  
Rayya A. Al-Balushi ◽  
Ashanul Haque ◽  
Idris J. Al-Busaidi ◽  
Houda Al-Sharji ◽  
Muhammad S. Khan
Keyword(s):  
Physical Properties ◽  
Main Chain ◽  
Functional Materials ◽  
Photo Luminescence ◽  
Structural Features ◽  
Side Chain ◽  
Structure Property ◽  
Molecular Scaffolds ◽  
Structure Property Relationships ◽  
Rigid Rod

Metalla-ynes and poly(metalla-ynes) have emerged as unique molecular scaffolds with fascinating structural features and intriguing photo-luminescence (PL) properties. Their rigid-rod conducting backbone with tunable photo-physical properties has generated immense research interests for the design and development of application-oriented functional materials. Introducing a second d- or f-block metal fragment in the main-chain or side-chain of a metalla-yne and poly(metalla-yne) was found to further modulate the underlying features/properties. This review focuses on the photo-physical properties and opto-electronic (O-E) applications of heterometal grafted metalla-ynes and poly(metalla-ynes).

The Relation between Structure and Physical Properties in Polyurethans

1962 ◽  
Vol 35 (4) ◽  
pp. 970-1012 ◽  
Author(s):  
Takehide Tanaka ◽  
Tetsuo Yokoyama
Keyword(s):  
Physical Properties ◽  
Polymer Structure ◽  
Structure And Properties ◽  
Structure Property ◽  
Chemical Structures ◽  
Structure Property Relationships ◽  
Polymer Properties ◽  
Wide Range ◽  
Number Of Publications ◽  
Broad Region

Abstract The field of polyurethans is rapidly growing in commercial importance, especially in form and elastomer applications. This group of polymers includes a very broad region of chemical structures and chain length. In many cases polyurethans are synthesized from polyester glycols or polyether glycols and diisocyanates so that the urethan groups are even fewer in number than other functional groups. This process of synthesis enables us to deal with a very wide range of polymer properties, adding interest to the studies of relation between structure and properties. Though a considerable number of publications dealing primarily with the properties of urethan polymers have been published, few of them contribute to better understanding of the relation between these properties and the corresponding polymer structure. Within the last few years information of value has become available, and Saunders has established some semi-quantitative relations by the use of such data. He also discusses in his reports general considerations concerning structure-property relationships. Although his considerations and conclusions show a marked progress, they are not theoretically satisfactory yet, especially from a quantitative viewpoint. The authors have investigated structure-property relationships in polyurethans for a few years and written some papers concerning synthesis, reaction kinetics, some physical properties, network structure, and dynamic behavior of polyurethans.

scholarly journals Laterally substituted symmetric and nonsymmetric salicylideneimine-based bent-core mesogens

2012 ◽  
Vol 8 ◽  
pp. 129-154 ◽  
Author(s):  
Sonja Findeisen-Tandel ◽  
Wolfgang Weissflog ◽  
Ute Baumeister ◽  
Gerhard Pelzl ◽  
H N Shreenivasa Murthy ◽  
...  
Keyword(s):  
Physical Properties ◽  
Liquid Crystalline ◽  
Optical Measurements ◽  
Disruptive Effect ◽  
Structure Property ◽  
Scanning Calorimetry ◽  
Structure Property Relationships ◽  
New Findings ◽  
Phenyl Rings ◽  
Intramolecular Hydrogen

Bent-core mesogens have gained considerable importance due to their ability to form new mesophases with unusual properties. Relationships between the chemical structure of bent-core molecules and the type and physical properties of the formed mesophases are relatively unknown in detail and differ strongly from those known for calamitic liquid crystals. In this paper symmetric and nonsymmetric five-ring salicylideneaniline-based bent-core mesogens are presented, and the effect of lateral substituents attached at the outer phenyl rings (F, Cl, Br) or the central phenyl ring (CH3) on the liquid-crystalline behaviour and on the physical properties is studied. Corresponding benzylideneaniline-based compounds were additionally prepared in order to study the influence of the intramolecular hydrogen bond. The occurring mesophases were investigated by differential scanning calorimetry, polarising microscopy, X-ray diffraction and dielectric and electro-optical measurements. The paper reports on new findings with respect to the structure–property relationships of bent-core mesogens. On one hand, the disruptive effect of laterally substituted halogen atoms, F, Cl and Br, on the mesophase behaviour of three isomeric series was much lower than expected. On the other hand, an increase of the clearing temperature by 34 K was observed, caused by small lateral substituents. The electro-optical behaviour, especially the type of polar switching and corresponding molecular movements, is sensitive to variations in the molecular structure.

Synthesis and Physical Properties of Self-Orienting Head-To-Tail Polythiophenes.

1993 ◽  
Vol 328 ◽  
Author(s):  
Richard D. McCullough ◽  
Shawn P. Williams ◽  
Manikandan Jayaraman ◽  
Jerry Reddinger ◽  
Lynnette Miller ◽  
...  
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Conjugated Polymers ◽  
Electrochemical Properties ◽  
Self Assembly ◽  
Structure Property ◽  
State Structure ◽  
Orbital Interactions ◽  
Structure Property Relationships ◽  
Designed Synthesis

ABSTRACTDesigned synthesis and architectural assembly of head-to-tail polythiophene derivatives provide the ability to control π orbital topology and orbital interactions in conjugated polymers. The preparation of polythiophene derivatives with essentially 100% head-to tail (HT) couplings leads to defect free polythiophenes. These new HT polythiophenes can undergo macromolecular self-assembly to give self-oriented conducting polymers. Study of these materials has led to new insights on structure-property relationships in this class of Materials. In addition, these results show that the molecular orbital overlap, the band dimensionality, and the solid state structure are quite sensitive to the nature of the side chains attached to the polymer's backbone. In addition, we have now synthesized the first heteroatom functionalized HT polythiophenes. These polythiophene derivatives can bind cations, and ion recognition can be used to tune conjugation lengths and properties in polythiophenes. Also presented are a class of random HT coupled 3-alkylthiophenes whose optical and electrochemical properties and possibly electronic properties can be altered by recipe.

scholarly journals Branched isomeric 1,2,3-triazolium-based ionic liquids: new insight into structure–property relationships

2015 ◽  
Vol 17 (44) ◽  
pp. 29834-29843 ◽  
Author(s):  
M. Lartey ◽  
J. Meyer-Ilse ◽  
J. D. Watkins ◽  
E. A. Roth ◽  
S. Bowser ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Physical Properties ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Insight Into

Series of branched isomeric 1,2,3-triazolium-based ionic liquids (ILs) were synthesized and characterized. The effect of branching on thermal and physical properties is investigated.

Structure-property relations of liquid crystalline polymers

1987 ◽  
Vol 45 ◽  
pp. 460-463
Author(s):  
Linda C. Sawyer
Keyword(s):  
Solid State ◽  
Liquid Crystalline ◽  
Structural Model ◽  
Crystalline Polymer ◽  
Liquid Crystalline Polymers ◽  
Mechanical Anisotropy ◽  
Structure Property ◽  
Preparation Methods ◽  
Crystalline Polymers ◽  
Extended Chain

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.

Sign in / Sign up

Export Citation Format

Share Document