Strength Variations during Mechanical Alloying Through the Nanostructural Range

2003 ◽  
Vol 791 ◽  
Author(s):  
Christopher A. Schuh ◽  
David T. Schoen ◽  
Alan C. Lund
Keyword(s):  
Mechanical Alloying ◽  
Domain Size ◽  
Phase Evolution ◽  
Length Scale ◽  
Structure Property ◽  
Final State ◽  
Length Scales ◽  
Structure Property Relationship ◽  
Chemical Mixing ◽  
Structural Length

ABSTRACTDuring processes of mechanical alloying the characteristic structural length scales of an alloy, including the phase domain size and the crystallite grain size, decrease gradually to a nanocrystalline or even amorphous final state. This method therefore allows a unique avenue to explore the structure-property relationship over several orders of magnitude in length scale. In this work we have considered an ideal equiatomic Ti-Zr system deformed through multiple cold-rolling passes to refine the structural length scales into the nanometer range. The variation of the hardness of the system with decreasing length scale is discussed in terms of traditional Hall-Petch scaling, chemical mixing and the phase evolution of the system, as well as other possible contributions to the hardness variations during processing.

Processing-Structure-Property Relations of Polymer-Polymer Composites Formed by Cryogenic Mechanical Alloying for Selective Laser Sintering Applications

2000 ◽  
Vol 625 ◽  
Author(s):  
J. P. Schultz ◽  
J. P. Martin ◽  
R. G. Kander ◽  
C. T. A. Suchicital
Keyword(s):  
Mechanical Alloying ◽  
Polymer Composites ◽  
Effective Means ◽  
Selective Laser Sintering ◽  
Domain Size ◽  
Laser Sintering ◽  
Charge Ratio ◽  
Composite Particles ◽  
Structure Property ◽  
Composite Powders

AbstractCryogenic mechanical alloying (CMA) has been shown to be an effective means for producing composite powders for selective laser sintering (SLS). Unlike composite particles made by a coating process, both phases are continuous throughout the particles formed by CMA. Consolidation of these composite particles via SLS offers the possibility of forming parts with a co-continuous microstructure. In this research, the microstructure of mechanically alloyed polymer-polymer composites for use in the SLS process is investigated using transmission electron microscopy. By varying the charge ratio and milling time of the CMA process, the phase domain size of the resulting composite powder can be manipulated. This ongoing work explores the microstructural evolution as the composite powders are consolidated via SLS into macroscopic parts, as well as the relationships between microstructure and bulk properties.

scholarly journals Microscopy and Microanalysis of Nano-Scale Materials

2006 ◽  
Vol 14 (5) ◽  
pp. 6-15 ◽  
Author(s):  
J. R. Michael ◽  
L. N. Brewer ◽  
D. C. Miller ◽  
K. R. Zavadil ◽  
S. V. Prasad ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Structure Property ◽  
Length Scales ◽  
Full Characterization ◽  
Microelectronic Devices ◽  
Structure Property Relationship ◽  
Scientists And Engineers ◽  
Physical And Chemical ◽  
And Chemical Properties

Material scientists and engineers continue to developmaterials and structures that are ever smaller. Some of this engineering is to simply domore with less while the science of nanomaterials allows new materials to be produced with a novel range of physical and chemical properties due to the small length scales of the microstructural features of thematerials. Currently, nanoscalematerials have been produced with a diverse set of useful properties and can be found in common substances like sunscreen or technologically advanced microelectronic devices. A complete understanding of materials is based on knowledge of the processing used to produce an interesting material coupled with a full characterization of the structure that results. It is this structure/property relationship that is the basis of understanding any newmaterial developed at all length scales.

Exploration of Bis(Arylimidazole) Iridium Picolinate Complexes

2017 ◽  
Author(s):  
Aron Huckaba ◽  
sadig aghazada ◽  
iwan zimmermann ◽  
giulia grancini ◽  
natalia gasilova ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Photophysical Properties ◽  
Structure Property ◽  
Aryl Group ◽  
Ligand Modification ◽  
Property Relationship ◽  
Structure Property Relationship

The straightforward synthesis and photophysical properties of a new series of heteroleptic Iridium (III) bis(2-arylimidazole) picolinate complexes is reported. Each complex has been characterized by NMR, UV-Vis, cyclic voltammetry, and the emissive properties of each is described. By systematically modifying first the cyclometallating aryl group on the arylimidazole ligand and then the picolinate ligand, the ramifications of ligand modification in these complexes was better understood through the construction of a structure-property relationship.

Exploration of Bis(Arylimidazole) Iridium Picolinate Complexes

2017 ◽  
Author(s):  
Aron Huckaba ◽  
sadig aghazada ◽  
iwan zimmermann ◽  
giulia grancini ◽  
natalia gasilova ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Photophysical Properties ◽  
Structure Property ◽  
Aryl Group ◽  
Ligand Modification ◽  
Property Relationship ◽  
Structure Property Relationship

The straightforward synthesis and photophysical properties of a new series of heteroleptic Iridium (III) bis(2-arylimidazole) picolinate complexes is reported. Each complex has been characterized by NMR, UV-Vis, cyclic voltammetry, and the emissive properties of each is described. By systematically modifying first the cyclometallating aryl group on the arylimidazole ligand and then the picolinate ligand, the ramifications of ligand modification in these complexes was better understood through the construction of a structure-property relationship.

Quantitative Structure-Property Relationship (QSPR) Study of the Hydrophobicity of Phenols and 2-(Aryloxy-a-acetyl)-phenoxathiin Derivatives

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Adrian Beteringhe ◽  
Ana Cristina Radutiu ◽  
Titus Constantinescu ◽  
Luminita Patron ◽  
Alexandru T. Balaban
Keyword(s):  
Water Solubility ◽  
Molecular Descriptors ◽  
Log P ◽  
Structure Property ◽  
Substituted Phenols ◽  
Reverse Phase ◽  
Aromaticity Index ◽  
Structure Property Relationship ◽  
Layer Chromatography ◽  
Energy Of Formation

In a preceding study, the molecular hydrophobicity (RM0) was determined experimentally from reverse-phase thin-layer chromatography data for several substituted phenols and 2-(aryloxy-a-acetyl)-phenoxathiin derivatives, obtained from the corresponding phenoxides and 2-(a-bromoacetyl)-phenoxathiin. QSPR correlations for RM0 were explored using four calculated molecular descriptors: the water solubility parameter (log Sw), log P, the Gibbs energy of formation (DGf), and the aromaticity index (HOMA). Triparametric correlations do not improve substantially the biparametric correlation of RM0 in terms of log Sw and HOMA.

Chitosan-Nanocellulose Composites for Regenerative Medicine Applications

2020 ◽  
Vol 27 (28) ◽  
pp. 4584-4592 ◽  
Author(s):  
Avik Khan ◽  
Baobin Wang ◽  
Yonghao Ni
Keyword(s):  
Regenerative Medicine ◽  
Preparation Method ◽  
Chemical Properties ◽  
Biological Properties ◽  
Next Generation ◽  
Structure Property ◽  
Physico Chemical ◽  
Structure Property Relationship ◽  
Attractive Candidate ◽  
Fundamental Understanding

Regenerative medicine represents an emerging multidisciplinary field that brings together engineering methods and complexity of life sciences into a unified fundamental understanding of structure-property relationship in micro/nano environment to develop the next generation of scaffolds and hydrogels to restore or improve tissue functions. Chitosan has several unique physico-chemical properties that make it a highly desirable polysaccharide for various applications such as, biomedical, food, nutraceutical, agriculture, packaging, coating, etc. However, the utilization of chitosan in regenerative medicine is often limited due to its inadequate mechanical, barrier and thermal properties. Cellulosic nanomaterials (CNs), owing to their exceptional mechanical strength, ease of chemical modification, biocompatibility and favorable interaction with chitosan, represent an attractive candidate for the fabrication of chitosan/ CNs scaffolds and hydrogels. The unique mechanical and biological properties of the chitosan/CNs bio-nanocomposite make them a material of choice for the development of next generation bio-scaffolds and hydrogels for regenerative medicine applications. In this review, we have summarized the preparation method, mechanical properties, morphology, cytotoxicity/ biocompatibility of chitosan/CNs nanocomposites for regenerative medicine applications, which comprises tissue engineering and wound dressing applications.

Quantitative Structure- Property Relationship (QSPR) Investigation of Camptothecin Drugs Derivatives

2018 ◽  
Vol 21 (7) ◽  
pp. 533-542 ◽  
Author(s):  
Neda Ahmadinejad ◽  
Fatemeh Shafiei ◽  
Tahereh Momeni Isfahani
Keyword(s):  
Thermodynamic Properties ◽  
Predictive Ability ◽  
Total Sample ◽  
Basis Sets ◽  
Quantitative Structure ◽  
Structure Property ◽  
Quantitative Structure Property Relationship ◽  
Chemical Structures ◽  
Property Relationship ◽  
Structure Property Relationship

Aim and Objective: Quantitative Structure- Property Relationship (QSPR) has been widely developed to derive a correlation between chemical structures of molecules to their known properties. In this study, QSPR models have been developed for modeling and predicting thermodynamic properties of 76 camptothecin derivatives using molecular descriptors. Materials and Methods: Thermodynamic properties of camptothecin such as the thermal energy, entropy and heat capacity were calculated at Hartree–Fock level of theory and 3-21G basis sets by Gaussian 09. Results: The appropriate descriptors for the studied properties are computed and optimized by the genetic algorithms (GA) and multiple linear regressions (MLR) method among the descriptors derived from the Dragon software. Leave-One-Out Cross-Validation (LOOCV) is used to evaluate predictive models by partitioning the total sample into training and test sets. Conclusion: The predictive ability of the models was found to be satisfactory and could be used for predicting thermodynamic properties of camptothecin derivatives.

Structure–property relationship of acceptor-substituted oligothiophenes

Tetrahedron ◽  
2010 ◽  
Vol 66 (45) ◽  
pp. 8729-8733 ◽  
Author(s):  
M.S. Wrackmeyer ◽  
M. Hummert ◽  
H. Hartmann ◽  
M.K. Riede ◽  
K. Leo
Keyword(s):  
Structure Property ◽  
Property Relationship ◽  
Structure Property Relationship ◽  
Relationship Of

Copolymerization of urea and murexide for efficient photocatalytic hydrogen evolution and tetracycline degradation

2021 ◽  
Author(s):  
Zhilu Du ◽  
Xinyu Zhao ◽  
Yingnan Zhao ◽  
Huiying Sun ◽  
Yingqi Li ◽  
...  
Keyword(s):  
Small Molecules ◽  
Hydrogen Evolution ◽  
Effective Strategy ◽  
Structure Property ◽  
Photocatalytic Hydrogen Evolution ◽  
Property Relationship ◽  
Structure Property Relationship ◽  
Tetracycline Degradation ◽  
Depth Study

Copolymerization of urea and small molecules is an effective strategy to modify g-C3N4. To in-depth study the important effects of the introduction of small molecular moiety on the structure-property relationship...

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