Home About us Contact
|
Home About us Contact | ||
|
|
||
Polythiophene Backbone (polythiophene + backbone)
Selected AbstractsAchieving Perpendicular Alignment of Rigid Polythiophene Backbones to the Substrate by Using Solvent-Vapor Treatment,ADVANCED MATERIALS, Issue 21 2007H. Lu The rigid backbone of the poly(3-butylthiophene) molecule adopts a perpendicular orientation with respect to the substrate by using a solvent-vapor treatment (see figure). Small and closely contacting spherulites instead of conventional whisker-like crystals are achieved. This could be utilized to improve charge-carrier mobility particularly in the direction normal to the film plane by designing and constructing thick crystalline domains in the functional layer. [source] Novel Thiophene-Thiazolothiazole Copolymers for Organic Field-Effect Transistors,ADVANCED MATERIALS, Issue 23 2007I. Osaka A semiconducting polymer bearing the thiazolothiazole moiety in the polythiophene backbone (see figure) is synthesized. The polymer is found to have small bandgap and large ionization potential. Despite the low molecular weight, the polymer exhibited a high field-effect mobility after annealing. A high on/off ratio suggests the polymer possesses high stability against oxygen doping. The polymer device also showed good environmental stability. [source] Synthesis, characterization and properties of azobenzene side-chain polythiophene,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-5 2003Leong Huat Gan Abstract Thiophene monomers with an azobenzene moiety of different spacer length at the 3-position of the thiophene ring were synthesized. The monomers were polymerized and copolymerized with 3-hexyl thiophene to investigate the influence of an azobenzene side-chain on the properties of polythiophene, which has been widely used as a conducting polymer and has also been found many other applications. The polymers were characterized with UV-vis, FT-IR spectrophotometry, gel permeation chromatographic (GPC) analysis, DSC, TGA, elemental analysis and X-ray diffractometry. The polymers showed novel thermochromic and photoresponsive properties in polymer solutions and solid films. It was found that an azobenzene side-chain could bring about substantial thermochromic and photochromic changes to the polythiophene backbone as compared with non-azobenzene side-chain polythiophenes. These property changes could be triggered or controlled by light or heat on the basis of azobenzene trans,cis or cis,trans isomerization. Copyright © 2003 John Wiley & Sons, Ltd. [source] Photoluminescent behavior of poly(3-hexylthiophene) derivatives with a high azobenzene content in the side chainsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2005Xiongyan Zhao Abstract A series of polythiophene derivatives with substantially higher azobenzene contents in the side chains were prepared via copolymerization of 3-hexylthiophene with four different types of 4-((4-(phenyl)azo)phenoxy)alkyl-3-thienylacetate. The alkyl spacers with different lengths, i.e. butyl, hexyl, octyl and undecyl groups were used between the azobenzene group and the thiophene ring. The compositions, structures and thermal properties of these polythiophene derivatives were characterized. The structural dependence of photoluminescent emission, photochromic behavior of these copolymers were systematically studied and compared with poly(3-hexylthiophene). The results show that the azobenzene substitution renders the polythiophene some interesting optical properties that can be modulated by UV light irradiation. In the azobenzene modified polythiophene, the intensity of photoluminescent emission associated with the conjugated polythiophene main chain was found to decrease significantly upon UV irradiation. The finding suggests that the photo-induced trans - cis isomerization of the azobenzene pendant groups has a significant effect on photoluminescent emission, particularly when short spacers are used between azobenzene groups and the main chain. However, the effect becomes less prominent when longer spacers are used between the azobenzene group and the main chain. Furthermore, UV irradiation of the copolymers also resulted in an increase in intensity and broadening of bandwidth for the absorption peak associated with the polythiophene backbones. Again the magnitude of intensity changes upon UV irradiation were found to be dependent on the spacer length between the azobenzene group and polythiophene main chain. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||