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 Physical and Electrochemical Properties of Soluble 3,4-Ethylenedioxythiophene (EDOT)-Based Copolymers Synthesized via Direct (Hetero)Arylation Polymerization

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiang Guo ◽  
Jincheng Zhang ◽  
Xiaoyu Li ◽  
Heqi Gong ◽  
Shuanghong Wu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Electrochemical Properties ◽  
High Performance ◽  
Molecular Conformation ◽  
Careful Study ◽  
Structure Property ◽  
Organic Electronic Devices ◽  
Molecular Weights ◽  
Structure Property Relationships ◽  
Electronic And Structural Properties

Over the past decades, π-conjugated polymers (CPs) have drawn more and more attention and been essential materials for applications in various organic electronic devices. Thereinto, conjugated polymers based on the 3,4-ethylenedioxythiophene (EDOT) backbone are among the high-performance materials. In order to investigate the structure–property relationships of EDOT-based polymers and further improve their electrochemical properties, a series of organic solvent–soluble EDOT-based alternative copolymers consisting of electron-rich fragments (fluorene P1, carbazole P2, and 3,4-alkoxythiophene P3) or electron-deficient moieties (benzotriazole P4 and thieno[3,4-c]pyrrole-4,6-dione P5) were synthesized via direct C–H (hetero)arylation polymerization (DHAP) in moderate to excellent yields (60–98%) with medium to high molecular weights (Mn = 3,100–94,000 Da). Owing to their various electronic and structural properties, different absorption spectra (λmax = 476, 380, 558, 563, and 603 nm) as well as different specific capacitances of 70, 68, 75, 51, and 25 F/g with 19, 10, 21, 26, and 69% of capacity retention after 1,000 cycles were observed for P1–P5, respectively. After careful study through multiple experimental measurements and theoretical calculation, appropriate electronic characteristics, small molecular conformation differences between different oxidative states, and well-ordered molecular stacking could improve the electrochemical performance of CPs.

scholarly journals Defining side chain successions in anthracene-based poly(arylene ethynylene)-alt-poly(phenylene vinylene)s: probing structure–property relationships

2019 ◽  
Vol 10 (39) ◽  
pp. 5339-5347
Author(s):  
Christoph Ulbricht ◽  
Nassima Bouguerra ◽  
Samuel Inack Ngi ◽  
Oliver Brüggemann ◽  
Daniel A. M. Egbe
Keyword(s):  
Conjugated Polymers ◽  
Spectroscopic Study ◽  
Side Chain ◽  
Phenylene Vinylene ◽  
Structure Property ◽  
Structure Property Relationships

A detailed spectroscopic study of nine conjugated polymers with various octyloxy/2-ethylhexyloxy side chain sequences prepared using optimized regio-selective synthetic pathways.

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.

scholarly journals Crystal chemistry and photomechanical behavior of 3,4-dimethoxycinnamic acid: correlation between maximum yield in the solid-state topochemical reaction and cooperative molecular motion

IUCrJ ◽  
2015 ◽  
Vol 2 (6) ◽  
pp. 653-660 ◽  
Author(s):  
Manish Kumar Mishra ◽  
Arijit Mukherjee ◽  
Upadrasta Ramamurty ◽  
Gautam R. Desiraju
Keyword(s):  
Solid State ◽  
Crystal Packing ◽  
Maximum Yield ◽  
Structure Property ◽  
Crystal Forms ◽  
Individual Crystal ◽  
Structure Property Relationships ◽  
Molecular Movement ◽  
Truxillic Acid ◽  
The Individual

A new monoclinic polymorph, form II (P21/c,Z= 4), has been isolated for 3,4-dimethoxycinnamic acid (DMCA). Its solid-state 2 + 2 photoreaction to the corresponding α-truxillic acid is different from that of the first polymorph, the triclinic form I (P\bar 1,Z= 4) that was reported in 1984. The crystal structures of the two forms are rather different. The two polymorphs also exhibit different photomechanical properties. Form I exhibits photosalient behavior but this effect is absent in form II. These properties can be explained on the basis of the crystal packing in the two forms. The nanoindentation technique is used to shed further insights into these structure−property relationships. A faster photoreaction in form I and a higher yield in form II are rationalized on the basis of the mechanical properties of the individual crystal forms. It is suggested that both Schmidt-type and Kaupp-type topochemistry are applicable for the solid-statetrans-cinnamic acid photodimerization reaction. Form I of DMCA is more plastic and seems to react under Kaupp-type conditions with maximum molecular movements. Form II is more brittle, and its interlocked structure seems to favor Schmidt-type topochemistry with minimum molecular movement.

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.

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