CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 41
·期 2
·288-296
·
IF 3.815
Tan Wan-Yi,Jian Ling-Feng,Chen Wei-Peng,Zhang Yong-Wen,Lu Xiao-Chuang,Huang Wan-Jun,Zhang Ji-Sheng,Wu Jing-Wu,Feng Jun-Li,Liu Yi-Dong,Cui Ting-Ting,Min Yong-Gang
Modified polyimides (MPIs) show great potential towards 5G communication applications, due to its excellent thermal stability, mechanical property and chemical stability as compared to most of polymers. Introducing fluoride groups or porous structure is favorable to ultra-low dielectric constant ( D k ) and dielectric loss ( D f ). However, the cost of the fluorinated MPIs is high and their synthetic processes are complicated, and porous MPIs suffer poor mechanical properties. Also, increasing the fraction of free volume is a very effective way to lower D k through introducing more ultra-low- D k air component. However, most of this kind of MPIs lag far behind the fluorinated MPIs and the porous MPIs in terms of ultra-low D f , hindering the application of MPIs in high-speed communication devices. Thus, it is highly desirable to develop intrinsic ultra-low- D k / D f MPIs at high frequency with less fluoric groups and nonporous structure. Herein, we introduce a facile and effective strategy to lower D k and D f through introducing rigid and large sterically hindered aromatic groups into MPIs. On the one hand, their large steric hindrance effect leads to low D k by increasing intrinsic free volume. On the other hand, the resulting highly stiff polymer chain and strong intermolecular interaction are favorable to reduce D f by inhibiting dipole orientations. Based on this strategy, the spirobifluorene groups are preferred. The as-prepared MPIs show excellent dielectric performance with low D k of 2.74–2.76 and low D f of 0.00599 at 10 GHz, to some extent, exceeding the multiple fluorinated MPI with D k / D f of 2.67/0.00663 at 10 GHz.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2013
·Vol. 5
·期 18
·4716-4722
·
IF 1.855
Bo Yang,Wenhui Wu
We have designed and synthesized a spirobifluorene–tetrrhodamine fluorescent probe 2 based on the through-bond energy transfer (TBET) system for the “off–on” detection of Hg2+. As compared with fluorescence resonance energy transfer (FRET) strategy, the TBET system did not need spectral overlap between the donor emission and the acceptor absorption, therefore, the choice of dye pairs for the probe design was wide. The Stokes shift was larger and the energy transfer efficiency was higher than that of the FRET system. The probe 2 showed exclusive response toward Hg2+ by the fluorescence enhancement and the color changed from colorless to pink. Other metal ions showed no significant variation to Hg2+. The energy-transfer efficiency was calculated to be 99.6%, and the detection limit was determined to be 3 ppb. Thus, probe 2 could be used as a fluorescent and colorimetric chemosensor for the detection of Hg2+.
研究领域:
化学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·8960-8967
·
IF 3.201
Yang Miao,Yincai Xu,Yuewei Zhang,Xianju Yan,Kaiqi Ye,Yue Wang
A water/alcohol soluble small molecular cathode interlayer (CIL) with the quaternary ammonium ions terminated by trihydroxybenzene as the pendant polar functionalities and a commercially available spirobifluorene (SBF) as a 3D-structural conjugated backbone, namely, TBSBF, was synthesized and applied in conventional single-junction polymer solar cells (PSCs). TBSBF was found to effectively enhance the performance of the PSCs by simultaneously increasing the open-circuit voltage (Voc), short-circuit current (Jsc) and fill factor (FF). Combined measurements of the current density–voltage characteristics, ultraviolet photoemission spectroscopy (UPS) and the electron mobility demonstrated that TBSBF could effectively increase the built-in potential and electronic mobility, leading to higher performance of the devices. In addition, the atomic force microscopy (AFM) measurements showed that TBSBF could self-assemble into a leopard print-like pattern on the hydrophobic active layer surface. These results not only indicate TBSBF is a promising CIL material for the future solution-processed PSCs, but also provide a new way to design efficient CILs with good film-formation properties.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Cuixia Yuan,Wenqing Liu,Minmin Shi,Shuixing Li,Yuzhou Wang,Huanle Chen,Chang-Zhi Li,Hongzheng Chen
In this paper, a non-fullerene electron acceptor , SF(DPPFB) 4 , which owns a spirobifluorene core and four diketopyrrolopyrrole (DPP) arms end capped by 4-fluorobenzene, is designed and synthesized for solution-processable organic solar cells (OSCs). SF(DPPFB) 4 shows similar absorption bands as those of its non-fluorinated parent compound, SF(DPPB) 4 . However, the terminal fluorine atoms reduce the energy levels of SF(DPPFB) 4 , especially, its lowest unoccupied molecular orbital level decreases by 0.04 eV than that of SF(DPPB) 4 , which enlarges the energy offset between the electron donor and acceptor, favorable for the dissociation of excitons in OSCs. Moreover, the fluorination improves the electron mobility of SF(DPPFB) 4 . Thus, the OSCs with poly(3-hexylthiophene) as the electron donor and SF(DPPFB) 4 as the electron acceptor can provide a maximum power conversion efficiency of 4.42%, with a lifted short-circuit current ( J sc ) of 8.48 mA cm −2 .
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2021
·
IF 4.889
You Liu,Fang Liu,Jungan Wang,Hongyan Huang,Suhao Yan,Song Gao,Lin Wang,Wei Huang,Tianshi Qin
Wide-bandgap photovoltaics (WBPV) could not only provide electrical energy by photoelectronic conversion of the invisible part of the solar spectrum, but also usually had the unique advantage of high open circuit voltage ( V oc). In this work, we reported a novel HTM based on tetrakis (N-phenothiazine) Spirobifluorene (Spiro-PT), its HOMO energy level could be well matched with MAPbBr 3 perovskite HOMO energy level. This HTM could effectively suppress nonradiative recombination, which leads to an increase in the photovoltage of WBPV to more than 1.41 V. As a result, the n-i-p mesoscopic structured WBPV achieved a champion PCE of 7.36% as well as excellent operational stability exhibiting 91% of initial efficiency after 500 h continuous illumination without encapsulation. Based on the high V oc of the MAPbBr 3 /Spiro-PT device, the photovoltaic electrochromic device showed a response speed (the average coloring time was 40 s and the bleaching time was 272 s) and high average visible light transmittance contrast (about 37% in 450–780 nm), the corresponding electrochromic device with maximum dynamic contrast up to 46% at 600 nm between bleached and colored states. This WBPV-powered electrochromic system could provide a pathway towards stand-alone smart window technique for future energy-saving buildings.
研究领域:
材料科学
·
光伏技术
·
纳米能源
·
智能窗技术
·
器件物理
✓ 已验证
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Zuolin Wu,Baochun Han,Chunhua Zhang,Danyang Zhu,Zhenghua Yang
Highly hydrophobic fluorinated polyimide aerogels were successfully prepared using a mild sol-gel method at room temperature from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2′-bis(trifluoromethyl)- 4,4′-diaminobiphenyl (TFDB), and cross-linked with 2,2′,7,7′-tetraamino-9,9′-spirobifluorene (TASBF). The obtained polyimide aerogels had low bulky density (0.118–0.161 g/cm 3 ), high specific surface areas (440.6–606.7 m 2 /g), small pore diameter (17.08–44.89 nm) and excellent mechanical property. These polyimide aerogels also exhibited high thermal stability in both nitrogen and air atmosphere, and the 5% weight loss occurred at temperatures above 530 °C. The introduction of 6FDA into polymer structures enhanced the hydrophobicity of the prepared polyimide aerogels. After replacing 50 mol % of BPDA with 6FDA in the oligomer backbone, water contact angles of the aerogels increased from 104.5° to 126.5°, and water absorption decreased from 4.3% to 2.1%. The high hydrophobicity makes these polyimide aerogels good candidates for use as thermal insulators in harsh environments and other applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Tongmou Geng,Guofeng Chen,Lanzhen Ma,Can Zhang,Weiyong Zhang,Heng Xu
Two new spirobifluorene-based conjugated microporous polymers, TS-TAD and TS-TADP, were constructed via Friedel-Crafts coupling reactions. TS-TAD and TS-TADP possess high BET surface area of 828 and 783 m 2 g −1 , large pore volume of 1.51 and 0.54 cm 3 g −1 , good stability, and display excellent guest uptake of 4.15 and 3.65 g g −1 in iodine vapour as well as reversible adsorption of iodine in solution. The specific surface areas of CMPs were increased by the introduction of bispirofluorene rings compared with the corresponding parent polymers. TS-TAD has a similar structure to TS-TADP, but possesses larger specific surface area and pore values than TS-TADP, hence, TS-TAD has a higher adsorption capacity for iodine than TS-TADP. Moreover, the adsorption rate of TS-TAD is slower than that of TS-TADP in I 2 vapor, while it is faster than that of TS-TADP in cyclohexane solution. We also highlight that the both resulting CMPs exhibit outstanding performance for fluorescent sensing to iodine and nitroaromatic compounds, thus making the resulting CMPs ideal absorbent materials for reversible iodine capture, sensing iodine and nitroaromatic compounds to address environmental issues.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Tianyong Zhang,Yamei Chai,Suisui Wang,Jianing Yu,Zihao Fang,Shuang Jiang,Bin Li
With the diminishing gap between the internal components of chips, the signal transmission delay poses a substantial threat to chip performance. To enhance the transmission speed of electrical signals, the development of materials with a low dielectric constant (D k ) becomes imperative. Polyimide (PI), categorized as a specialized engineering material, exhibits a high D k (≥3), posing challenges in meeting the requirements of electronic and communication industries. Consequently, a new diamine monomer named BTVFD, characterized by spirobifluorene and cross-linkable tetrafluorostyrol groups, was synthesized. It was copolymerized with 2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diamine (TFDB) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to synthetize cross-linkable polyimides (TBPIs) with different BTVFD content. The cross-linked TBPIs (CL-TBPIs) were obtained by thermal cross-linking reaction. The study results demonstrate the D k of PIs is significantly reduced through this effective strategy. Notably, CL-TBPI-2 exhibits outstanding comprehensive performance with low D k (1.88@10 MHz) and dielectric loss (0.00513@10 MHz), low water uptake (0.125 %), high thermal decomposition temperature (5 % weight loss at 553 °C) and glass transition temperature (374 °C), excellent tensile strength (121.8 MPa) and nice transparency and flexibility.
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
危险品化学品经营许可证（带存储）