SYNTHETIC METALS
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2021
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IF 3.266
Yanyu Gao,Wei Zhang,Dongxu Li,Xiaoxue Lin,Xin Qiao,Haijun Niu,Wen Wang
Electrochromic (EC) materials have captured intense attentions in the field of smart window, label screen and camouflage recently. The structure of EC active group is crucial to the properties of product. In this study, novel PAs with EC and memory properties were developed by polycondensation of asymmetry triarylamine N, N ' -bis(4-aminophenyl)-N-isopropyl-N ' -phenylbenzene-1,4-diamine (IPATAA) with five different dicarboxylic monomers. An isopropyl group of the IPATAA molecule is linked to a nitrogen atom to increase electron density and solubility. Furthermore, PAs are apt to be processed into a film by spin-coating or printing. After electro-oxidation, PAs films change from colorless to blue. The coloring time and bleaching time is 2.8–4.1 s and 2.6–4.5 s, respectively. The highest coloring efficiency of PAs film is 366 cm 2 C −1 . Memory devices made using the PAs show non-volatile memory characteristics such as lower switching threshold voltages (<1.08 V) and better switching current ratios (>2 × 10 4 ).
研究领域:
材料科学
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电子器件
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 30
·25302-25310
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IF 3.289
Nafeesa Mushtaq,Guofei Chen,Lala Rukh Sidra,Xingzhong Fang
To investigate the asymmetric effect of the naphthalimide moiety on the thermal, mechanical, optical properties and water uptake of polyimides (PIs), two novel asymmetric diamines, 4-(4-aminophenoxy)-N-amino-1,8-naphthalimide 3 and 4-(4-aminophenoxy)-N-(4-aminophenyl)-1,8-naphthalimide 4 were synthesized. Two series of PIs 5b–e and 6a–e were prepared from diamines 3 and 4 by solution polymerization method, respectively. The resulting polyimides demonstrated good solubility, high glass transition temperature (Tg) of 311–421 °C and good thermal stability based on the 5% weight loss temperature (T5%) of 435–563 °C in nitrogen. These PIs also exhibited good mechanical properties with tensile strengths of 107.3–172.2 MPa, tensile moduli of 2.8–4.9 GPa, and elongations at break of 2.9–9.1%. The water uptake of PIs was in the range of 0.33–1.96%. The polyimides displayed UV-vis absorption maxima and an intense fluorescent intensity in the range of 361–371 and 480–700 nm, respectively.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Guoliang Tong,Yue Chen,Xingfu Xiao,Junjie Tang,Biqi He,Sheng Cao,Mingkai Li,Yunbin He,Junnian Chen
Two-dimensional (2D) Dion-Jacobson (DJ) perovskites are drawing significant attention in optoelectronic fields because of their enhanced out-of-plane electron coupling and improved structure stability. However, the structural effects of organic cations on the in-plane charge transport properties of 2D DJ lead bromide perovskites have remained less explored. Herein, we adopt asymmetric 3-(dimethylamino)-1-propylammonium (DMPD) and symmetric butane-1,4-diammonium (BDA) to systematically investigate the influence of organic cations on the structural, optical, and in-plane charge transport properties of 2D lead bromide perovskites. The large penetration depth of DMPD2+ induces a decreased perovskite layer distortion and a lower bandgap in DMPDPbBr4, compared with that of BDAPbBr4. Moreover, DMPDPbBr4 is shown to possess a low exciton binding energy, a low defect density, and a low ion migration activation energy, thereby yielding a more efficient in-plane charge collection efficiency than BDAPbBr4. Density functional theory calculations suggest that the improved in-plane charge transport can be traced to the enlarged antibonding coupling between Pb–6s and Br–4p orbitals that enables a high band dispersion and a low carrier effective mass in the in-plane direction of DMPDPbBr4. Finally, the planar Ag/DMPDPbBr4/Ag photodetector delivers a satisfying detectivity of 1.73 × 1012 Jones under an incident power intensity of 0.16 mW cm–2 and a high on/off ratio of 5.3 × 103. The above findings offer novel insight for the design of 2D DJ lead bromide perovskites for optoelectronic devices.
研究领域:
材料科学
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光学工程
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产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Min Zhong,Xiuming Wu,Chen Shu,Yuling Wang,Xingyi Huang,Wei Huang
A series of polyimides (PIs) containing a bulky side group of m -trifluoromethyl phenyl was synthesized via a high-temperature one-step polycondensation of 4-[3′,5′-bis(trifluoromethyl)phenyl]-1,3-phenylenediamine ( 2 ) and various aromatic dianhydrides. The weight-averaged molecular weights ( M w ) of the resulting PIs are between 3.92 and 8.36 × 10 4 g mol −1 with the M w / M n of 1.77–2.09. They are soluble in common organic solvents and easily processed into flexible films by the blade coating of PI solution. At room temperature , the dielectric constants ( k ) of these PI films are lower than 3.04 at 1 MHz and 2.87 at 10 GHz, especially the k of 2 -6FDA film is low to 2.66 at 1 MHz and 2.38 at 10 GHz. The breakdown strength of the resulting PI films (thickness: 10 ± 1 μm) is in the range from 461 to 523 kV mm −1 . Meanwhile, these PI films also show good thermal stability (5 wt% weight-loss temperature in the range of 521–571 °C under N 2 ; glass transition temperatures of 266–307 °C) and mechanical properties (tensile strength of 70.8–103.3 MPa, tensile modulus of 1.3–2.2 GPa, elongation at break of 9.1–10.8%). The average transmittance of these PI films (around 20 μm) is above 80% in the visible light region (400–760 nm). Such attractive comprehensive properties make these PIs as potential candidates for application in microelectronics industry.
研究领域:
材料科学
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高分子化学
·
电子材料
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Qilin Xu,Huachun Fan,Hongmiao Yao,Duoheng Wang,Hangwei Yu,Bingbing Chen,Zhiqun Yu,Weike Su
Monoacylated symmetrical diamines are building blocks or intermediates of several well-established drugs. However, for the symmetrical diamines, the two amine groups located in a similar chemical environment make the selective monoacylation rather difficult and no kinetics study has ever been reported before. To comprehend this kind of reaction more deeply, a continuous flow microfluidic system was developed to evaluate the reaction kinetics of m -phenylenediamine and benzoic anhydride. At first, the reaction order of each reactant, pre-exponential factors and activation energies were determined in turn. The possible reaction mechanism was postulated from the reaction order. Then, a series of validation experiments were designed to show the accuracy and the applied range (concentration and temperature) of the kinetic model. Next, to obtain a controlled selectivity, the effects of initial concentration, reaction temperature and molar ratio on the selectivity were investigated through the model simulation. In the end, under the conditions optimized by the kinetic model, 96.9% selectivity and 92.5% yield were obtained in the microreactor.
研究领域:
有机化学
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药物化学
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化学工程
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DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Lala Rukh Sidra,Guofei Chen,Cuiyun Li,Nafeesa Mushtaq,Kai Ma,Xingzhong Fang
Two novel unsymmetric diamine isomers, 6-amino-2-(4-(4-aminophenoxy)phenyl)-1H-benzimidazole (3p) and 6-amino-2-(3-(4-aminophenoxy)phenyl)-1H-benzimidazole (3 m), were synthesized and employed to react with several aromatic dianhydrides to yield two new series of poly (benzimidazole imide)s (PBIPIs), PI-4 (a-e) and PI-5 (c-e) through two-step and one step polymerization method, respectively. The effect of chain isomerism on molecular packing and physical properties of PBIPIs is investigated. Both series exhibited excellent thermal stability ( T 5% = 503–559 °C), high T g values (276–383 °C) and good mechanical properties (tensile strengths of 98–151 MPa and tensile moduli of 3.5–5.2 GPa). The PI-5 (c-e) showed high solubility compared to PI-4 (a-e) series. Such improved solubility attributed to the flexible ether connecting groups with non-coplanarity. Furthermore, controlled molecular weight ( Mw ) polymer PI-5e-PA derived from 3 m, demonstrated good solution and melt processability.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
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