ORGANIC ELECTRONICS
·
2019
·
IF 3.495
Yan Zhang,Hongmei Du,Yiming Yin,Yunyun Dong,Jinsheng Zhao,Zhen Xu
Three soluble donor-acceptor (D-A) type copolymers employing benzene (B) as donor, 2-dodecyl-4,7-di(thiophen-2-yl)-2H-benzo [d][1,2,3]triazole (Z) and 2,3-bis((4-(2-octyldodecyl)oxy)phenyl)-quinoxaline (Q) as acceptors were synthesized through chemical polymerization. A variety of characterization methods such as cyclic voltammetry , UV–vis spectroscopy, colorimetry and thermogravimetric analysis were executed to detect the electrochromic properties of polymers. All the polymers displayed multicolor in the redox process with medium band gaps, and different molar ratio of B/Z/Q allowed them to cover diverse color changes, containing orange-red/brown-yellow/cyan/green (PBZQ-1), orange-red/yellow/light grass green (PBZQ-2), and red/black/grey-blue (PBZQ-3). The multichromism of the polymers involved RGB and black colors. Meanwhile, with the increase of Z unit ratio and the decrease of Q unit ratio, the polymer demonstrated the reduced onset oxidation potential and optical band gap, as well as the different kinetic parameters . Moreover, the three polymers exhibited good solubility, desirable thermal stability, relatively large optical contrast and high coloration efficiency. The above positive results implied that these copolymers were expected to be the credible candidates for the electrochromic devices with commercial values.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2016
·
IF 2.244
Dingqian Shi,Kun Hu,Pei Chen,Weisong Du,Aiai Gao,Ran Chen,Xinbing Chen,Zhongwei An
A series of nematic heterocyclic liquid crystals, 2-(2ʹ-fluoro-4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-benzoxazole derivatives (coded as nPF(2)PBx) bearing hydrogen (nPF(2)PBH), methyl (nPF(2)PBM) and nitro (nPF(2)PBN) terminal groups, respectively, are developped and investigated. The results show that the nematic mesophase stability is obviously improved via a slightly increase in the inter-ring twist angle between the planes of two phenyl rings in the biphenyl unit, where modification of the twist angle can be achieved by adjusting the position of the lateral monofluorine substituent from the outer to the inter ring of the biphenyl mesogenic core unit. Meanwhile, the inter-ring lateral fluorine substituent results in a decrease in both melting and clearing points but only a nematic mesophase with an acceptably wide mesophase range for nPF(2)PBx, and thus a potential application in liquid crystal display mixtures is expected, especially for the compounds nPF(2)PBM and nPF(2)PBN. The reduced π–π interaction/conjugation caused by the increased twist angle is considered as one of the possible reasons for the formation of a nematic mesophase.
研究领域:
材料科学
·
液晶化学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2024
·
IF 4.1
Leyao Zhao,Jing Sun,Qiang Fang
Two monomers with adamantane units as the linker and benzocyclobutene (BCB) groups as the crosslinking units have been successfully synthesized, and they are thermally treated to form polymers with a 5% weight loss temperature of up to 478 °C and a glass transition temperature of more than 350 °C. Among the polymers, the one containing fluorobenzene units displays a dielectric constant (Dk) of 2.58 and a dielectric loss (Df) of 1.94 × 10−3 at a frequency of 10 GHz. Such a fluoro-containing polymer also exhibits a water uptake of 0.12% even when immersing it in boiling water for 72 h. These results demonstrate that the two polymers are suitable as low dielectric materials for application in the fabrication of devices used in high-frequency communication.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2019
·
IF 3.078
Qiang Weng,Longyan Duan,Pei Chen,Aiai Gao,Xinbing Chen,Zhongwei An
Modifying the position and numbers of lateral fluorine substituent is a common method to design and adjust the mesophase of liquid crystal compounds. Here, a series of 2-(2,2ʹ-difluoro-4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-5-substituted benzoxazole with both non-polar (H, CH3) and polar (NO2) groups (coded as nPF(2)PF(2)Bx) is synthesised and characterised. All of the compounds show a conspicuous inter-ring twist angle of 38° compared with corresponding reference compounds I and II which are calculated by density functional theory method, and it is interesting to note that the final compounds nPF(2)PF(2)Bx show only nematic mesophase during heating or cooling. Meanwhile, the UV-vis absorption bands and photoluminescence emission peaks both display remarkable blue-shifted. The aforementioned results reveal that lateral difluoro substituents play a key role to stable the nematic mesophase by increasing the dihedral angle of biphenyl.
研究领域:
材料科学
·
化学
·
液晶
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 44
·23191-23201
·
IF 3.708
Gang Zhang,Shu-shan Yuan,Zhi-min Li,Sheng-ru Long,Jie Yang
Two kinds of high glass temperature poly(arylene ether sulfone)s containing thioether and biphenyl units (PASSs) have been developed. The polymers were prepared by a polycondensation reaction of 4,4′-bis(4-chlorophenylsulfone)biphenyl (BCPSB) and 4,4′-dimercaptodiphenyl sulfone (DMDPS) (or 4,4′-bis(4-mercaptophenylsulfone)biphenyl (BMPSB)). They showed good thermal properties such as a relatively high glass transition temperature of 263–282 °C and a 5% weight-loss temperature (T5%) of 441–445 °C. The water flux and retention rate of the resultant membranes were 0.61–2.48 L m−2 h−1 and 89.47–94.91%, respectively. Interestingly, we found that the corrosion resistance of the membranes had been largely improved with the oxidization treatment. They were even insoluble in NMP, DMSO, concentrated H2SO4, aqua regia and so on, while the polymers without oxidation were soluble or destroyed in above solvents. In addition, we found the water flux of the oxidized membrane was also improved but the retention rate only decreased a little.
研究领域:
材料科学
·
高分子化学
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）