There are no files associated with this item.
Full metadata record
DC Field | Value | Language |
---|---|---|
dc.citation.endPage | 4182 | - |
dc.citation.number | 24 | - |
dc.citation.startPage | 4172 | - |
dc.citation.title | JOURNAL OF MATERIALS CHEMISTRY | - |
dc.citation.volume | 19 | - |
dc.contributor.author | Baek, Jong-Beom | - |
dc.contributor.author | Lyons, Christopher B. | - |
dc.contributor.author | Tan, Loon-Seng | - |
dc.date.accessioned | 2023-12-22T08:06:25Z | - |
dc.date.available | 2023-12-22T08:06:25Z | - |
dc.date.created | 2013-06-17 | - |
dc.date.issued | 2009-06 | - |
dc.description.abstract | A series of hyperbranched poly(etherketone)-b-poly(benzobisthiazole)-b-hyperbranched poly(etherketone) triblock copolymers were synthesized. Two different types of hyperbranched poly(etherketone)s (PEKs) were utilized as dendritic A-block units and carboxylic acid-terminated polybenzobisthiazoles (PBZTs) with two different molecular weights as a conjugated, optically responsive, rigid-rod B-block units to afford dumbbell-shaped ABA triblock copolymers. Although all dumbbell-shaped samples are soluble in strong acids such as trifluoroacetic acid (TFA), methanesulfonic acid (MSA), trifluoromethanesulfonic acid (TFMSA) and sulfuric acid, only phenoxy-terminated dumbbell shaped triblock copolymers (3a and 3b) were soluble in common polar aprotic solvents such as NMP, DMF, DMAc and DMSO. Their solubility in common organic solvents was apparently a consequence arising from the obstruction of the close packing of PBZT components by the bulky dendritic PEK ends. A very surprising and interesting observation was made when the 3a and 3b solutions in NMP were placed under room light for 24 h: all major absorption peaks became featureless and blue-shifted. This photochromism was investigated by static and dynamic UV-absorption and fluorescence spectroscopy under various conditions. Although the response time was quite long, it could be controlled as a function of excitation wavelength, light intensity, and solvent viscosity and/or polarity. We propose that the origin of observed spectral changes is caused by the change in conjugation lengths of PBZT in the dumbbell-shaped ABA triblock copolymers. | - |
dc.identifier.bibliographicCitation | JOURNAL OF MATERIALS CHEMISTRY, v.19, no.24, pp.4172 - 4182 | - |
dc.identifier.doi | 10.1039/b901483g | - |
dc.identifier.issn | 0959-9428 | - |
dc.identifier.scopusid | 2-s2.0-67149141759 | - |
dc.identifier.uri | https://scholarworks.unist.ac.kr/handle/201301/2597 | - |
dc.identifier.url | http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=67149141759 | - |
dc.identifier.wosid | 000266797500017 | - |
dc.language | 영어 | - |
dc.publisher | ROYAL SOC CHEMISTRY | - |
dc.title | Macromolecular dumbbells: synthesis and photophysical properties of hyperbranched poly(etherketone)-b-polybenzobisthiazole-b-hyperbranched poly(etherketone) ABA triblock copolymers | - |
dc.type | Article | - |
dc.description.isOpenAccess | FALSE | - |
dc.relation.journalWebOfScienceCategory | Chemistry, Physical; Materials Science, Multidisciplinary | - |
dc.relation.journalResearchArea | Chemistry; Materials Science | - |
dc.description.journalRegisteredClass | scopus | - |
dc.subject.keywordPlus | DENDRITIC BLOCK-COPOLYMERS | - |
dc.subject.keywordPlus | ATOMIC-FORCE MICROSCOPY | - |
dc.subject.keywordPlus | PARA-AROMATIC POLYMERS | - |
dc.subject.keywordPlus | LIGHT-EMITTING-DIODES | - |
dc.subject.keywordPlus | RIGID-ROD POLYMERS | - |
dc.subject.keywordPlus | CONJUGATED POLYMERS | - |
dc.subject.keywordPlus | THERMAL-PROPERTIES | - |
dc.subject.keywordPlus | MOLECULAR BRUSHES | - |
dc.subject.keywordPlus | MAIN CHAIN | - |
dc.subject.keywordPlus | MONOMERS | - |
Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Tel : 052-217-1404 / Email : scholarworks@unist.ac.kr
Copyright (c) 2023 by UNIST LIBRARY. All rights reserved.
ScholarWorks@UNIST was established as an OAK Project for the National Library of Korea.