Effect of Sequence Distribution of Oxadiazole Moieties on Luminescence in a Poly(Phenylene-Vinylene) Derivative

2002 ◽  
Vol 725 ◽  
Author(s):  
Subramanian Vaidyanathan ◽  
Mary E. Galvin
Keyword(s):  
Chemical Composition ◽  
Random Copolymer ◽  
Semiconducting Polymers ◽  
Phenylene Vinylene ◽  
Structure Property ◽  
Sequence Distribution ◽  
Alternating Copolymer ◽  
Structure Property Relationships ◽  
Better Than

AbstractIn order to realize the vast potential offered by semiconducting polymers in emissive display technologies, it is important to understand the structure-property relationships that govern their performance. This paper will focus on one such relationship in the most widely studied class of polymers viz. poly(phenylene-vinylene) (PPV) derivatives. We have synthesized oxadiazole containing PPV copolymers varying the composition and sequence distribution of the oxadiazole moiety in the chain. We find that a statistically random copolymer performs 50% better in EL efficiency than the corresponding alternating copolymer with the same chemical composition, and 3 times better than the homopolymer without any oxadiazole moieties.

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 Progressions in reasoning about structure–property relationships

2018 ◽  
Vol 19 (4) ◽  
pp. 998-1009 ◽  
Author(s):  
Vicente Talanquer
Keyword(s):  
Molecular Structure ◽  
Chemical Composition ◽  
Chemistry Education ◽  
Traditional Instruction ◽  
Structure Property ◽  
Student Reasoning ◽  
Structure Property Relationships ◽  
And Behaviors

In this essay, findings from research in science and chemistry education are used to describe and discuss progression in students' structure–property reasoning through schooling. This work provides insights into the challenges that students face to master this important component of chemical thinking. The analysis reveals that student reasoning is often guided by nonnormative implicit schemas that are little affected by traditional instruction. These schemas prioritize chemical composition over molecular structure, and centralized causality over emergence in the explanation and prediction of the properties of substances. The types of components that students invoke to make sense of properties and phenomena may change with schooling, but the underlying reasoning persists. In general, learners assume that observed properties and behaviors are directly related to the types of atoms present in a system and determined by these individual atoms' inherent characteristics.

Semiconducting Polymers for Multidisciplinary Education

2000 ◽  
Vol 632 ◽  
Author(s):  
David Braun ◽  
Kevin Kingsbury ◽  
Linda Vanasupa
Keyword(s):  
Engineering Students ◽  
Semiconductor Device ◽  
Device Fabrication ◽  
Semiconducting Polymers ◽  
Structure Property ◽  
Chemistry Students ◽  
Materials Engineering ◽  
Structure Property Relationships ◽  
Core Concepts ◽  
Interdisciplinary Projects

ABSTRACTCal Poly is in the process of revolutionizing how science and engineering students learn about semiconducting materials. Semiconducting polymers currently attract widespread attention as the subjects of numerous research and development projects. Semiconducting polymers are also excellent materials with which to teach structure-property relationships, polymer synthesis, polymer film preparation, optical and electronic properties, semiconductor device fabrication principles, and device testing.One key benefit of these materials is that they encourage student participation in educational activities that bridge several disciplines. Semiconducting polymers improve student learning by making normally obscure semiconductor concepts more tangible for students in several disciplines: chemistry students create electronics applications for the compounds they synthesize, materials engineering students learn about opto-electronics techniques, and electrical engineering students gain hands-on experience with core concepts in semiconductor devices.This presentation describes the interdisciplinary projects that students and faculty have participated in thus far, particularly during the phase of lab design and construction.

Structure–Property Relationships of Semiconducting Polymers for Flexible and Durable Polymer Field-Effect Transistors

2017 ◽  
Vol 9 (46) ◽  
pp. 40503-40515 ◽  
Author(s):  
Min Je Kim ◽  
A-Ra Jung ◽  
Myeongjae Lee ◽  
Dongjin Kim ◽  
Suhee Ro ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Semiconducting Polymers ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Durable Polymer

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

Approaches for TEM imaging of cavitation in toughened nylon

1989 ◽  
Vol 47 ◽  
pp. 352-353
Author(s):  
Barbara A. Wood
Keyword(s):  
Morphological Characteristics ◽  
Structure Property ◽  
Polymer Systems ◽  
Selective Staining ◽  
Structure Property Relationships ◽  
Rubber Toughened ◽  
Shear Yield ◽  
Controversial Topic ◽  
Selection Of ◽  
Diamond Knife

A controversial topic in the study of structure-property relationships of toughened polymer systems is the internal cavitation of toughener particles resulting from damage on impact or tensile deformation.Detailed observations of the influence of morphological characteristics such as particle size distribution on deformation mechanisms such as shear yield and cavitation could provide valuable guidance for selection of processing conditions, but TEM observation of damaged zones presents some experimental difficulties.Previously published TEM images of impact fractured toughened nylon show holes but contrast between matrix and toughener is lacking; other systems investigated have clearly shown cavitated impact modifier particles. In rubber toughened nylon, the physical characteristics of cavitated material differ from undamaged material to the extent that sectioning of heavily damaged regions by cryoultramicrotomy with a diamond knife results in sections of greater than optimum thickness (Figure 1). The detailed morphology is obscured despite selective staining of the rubber phase using the ruthenium trichloride route to ruthenium tetroxide.

Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Near-Infrared Light

2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transient Absorption ◽  
Reaction Times ◽  
Infrared Light ◽  
Structure Property ◽  
Light Emitting ◽  
Structure Property Relationships ◽  
Nir Light ◽  
Light Intensities ◽  
Emission Quenching

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

A Review on Camptothecin Analogs with Promising Cytotoxic Profile

2019 ◽  
Vol 18 (13) ◽  
pp. 1796-1814 ◽  
Author(s):  
Sk. Abdul Amin ◽  
Nilanjan Adhikari ◽  
Tarun Jha ◽  
Shovanlal Gayen
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
Structure Property ◽  
Cytotoxic Potential ◽  
Structure Property Relationships ◽  
Structure Activity ◽  
Camptothecin Analogs ◽  
Pharmacokinetic Properties ◽  
Quantitative Structure Activity Relationships

Camptothecin (CPT), obtained from Camptotheca acuminata (Nyssaceae), is a quinoline type of alkaloid. Apart from various traditional uses, it is mainly used as a potential cytotoxic agent acting against a variety of cancer cell lines. Though searches have been continued for last six decades, still it is a demanding task to design potent and cytotoxic CPTs. Different CPT analogs are synthesized to enhance the cytotoxic potential as well as to increase the pharmacokinetic properties of these analogs. Some of these analogs were proven to be clinically effective in different cancer cell lines. In this article, different CPT analogs have been highlighted extensively to get a detail insight about the structure-property relationships as well as different quantitative structure-activity relationships (QSARs) modeling of these analogs are also discussed. This study may be beneficial for designing newer CPT analogs in future.

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