CHINESE JOURNAL OF CHEMISTRY
·
2011
·Vol. 29
·期 9
·1906-1910
·
IF 0.773
Lin Yan,Wenguo Yang,Lixin Li,Yang Shen,Zhiyong Jiang
A mild and facile Wittig reaction between N -substituted maleimides and aldehydes has been developed. Various synthetically valuable alkylidenesuccinimides were obtained from this one-pot reaction in high yields (up to 99%). The product was obtained by simple filtration and no extra purification was necessary. Ethanol, an environment-benign solvent, was found to be a suitable reaction medium.
研究领域:
有机化学
·
药物化学
·
绿色化学
·
合成方法学
·
medicinal chemistry
✓ 已验证
DOI
高影响因子
TRIBOLOGY LETTERS
·
2019
·Vol. 67
·期 1
·1-17
·
IF 2.235
Zhao Yuanliang,Qi Xiaowen,Zhang Wenli,Fan Bingli,Yang Qingxiang
The effects of copper nanoparticles (Cu) located in different regions of polytetrafluoroethylene/polyimide (PTFE/PI) blends on the morphology, thermal, mechanical, and tribological properties of PTFE composites were studied. Region one is PI phases (the corresponding composites is denoted as PPC), region two is PTFE phases and the interface between PTFE and PI (the corresponding composites is denoted as PPC-m). Results indicate that the incorporation of Cu nanoparticles into PI phases improves the dispersibility and homogeneity of PI phases. As a consequence, the crystallinity of PTFE composites is reduced, but compressive strength and modulus of PTFE composites are enhanced by 50.3% and 14.4% respectively. In addition, self-lubricity and wear resistance of PTFE composites are improved by 10.4% and 50.5%. Scanning electron microscopy (SEM) demonstrates that PI phases with Cu nanoparticles hinder the direct contact between PTFE matrix and counterparts. However, Cu nanoparticles located in PTFE matrix and the interface between PTFE and PI deteriorates the dispersibility and homogeneity of PI phases, which lead to the poor mechanical and tribological performance of PTFE composites.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 11
·2100456
·
IF 4.367
Zhiqiang Wu,Qiang Guo,Yang Liu,Huihui Zhou,Hua Zheng,Xingfeng Lei,Lei Gong,Yanhui Chen,Zhenguo Liu,Qiuyu Zhang
In order to meet the requirements of polymer dielectric materials for high thermal stability and excellent dielectric properties in the application of high-temperature film capacitors, a series of polyimide (PI) films are fabricated by introducing a self-synthesized aniline trimer (ACAT) with a conjugated structure in this work. Since the conjugated ACAT in the main chains of PI improves the electron polarization and carrier mobility of the PI molecular chains, the dielectric constant of the ACAT-PI films is greatly enhanced (4.4–7.4). Meanwhile, the dissipation factor does not increase apparently (0.002–0.013). The dielectric properties are stable even when the temperature is up to 200 °C, the thermal degradation temperature is as high as 450 °C, and the mechanical properties are also excellent (70–105 MPa). Among all the films, the PI film with 5 mol% ACAT exhibits the maximal energy density of 3.6 J cm −3 under the field of 426 kV mm −1 , the high tensile strength (90 MPa) and the excellent thermal stability ( T d5 = 515 °C). The work paves the way to prepare high-temperature polymer dielectric film materials with high energy storage density.
研究领域:
材料科学
·
高分子化学
·
介电物理
·
能源材料
·
功能高分子
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 217
·期 24
·2726-2735
·
IF 2.495
Huiliang Sun,Shuren Zhang,Yike Yang,Xiao Li,Hongmei Zhan,Yanxiang Cheng
Six aryl Pd(II) bromide complexes based on perylene diimide derivative (Ar) and phosphine mixed-ligands are successfully synthesized by directly oxidative addition of Ar–Br to the Pd(0) precursor. These complexes with the general formulas ArPdBr(PCy 3 ) 2 (PCy 3 = tricyclohexylphosphine; Pd1–Pd3 ) and [ArPdBr(TXP-2,4)] 2 (TXP-2,4 = tri-2,4-xylylphosphine; Pd4–Pd6 ) are stable and can be handled in air at room temperature. By employing the Pd(II) complexes as initiators, Suzuki catalyst transfer polymerization (SCTP) of AB-type fluorene monomer is investigated for preparing polyfluorenes (PFs) with the defined end group. Complexes Pd4–Pd6 with auxiliary TXP-2,4 ligand can initiate polymerization of AB-type fluorene monomer at room temperature, while higher polymerization temperature is required for Pd1–Pd3 with alkyl phosphine PCy 3 . The obtained polymers are analyzed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, which confirms that the Ar group is appended to the terminus of the polymer chain. Moreover, PFs prepared by Pd4–Pd6 -catalyzed SCTP bear precisely the Ar group on one chain end and 4- tert -butylphenyl end-capping group on the opposite end, which indicates that Pd4–Pd6 with the bulky TXP-2,4 exhibit better catalytic performance in SCTP. Photoluminescence spectra of the obtained polymers show a dual or a blue emission resulting from the difference of the molecular weight.
研究领域:
高分子化学
·
有机合成
·
功能材料
·
聚合反应机理
·
光电子材料
✓ 已验证
DOI
高影响因子
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
·
2017
·
IF 3.756
Yu Huang,Jin-Mei Li,Zhi-Hui Lai,Jun Wu,Tong-Bu Lu,Jia-Mei Chen
Both cocrystal and nanocrystal technologies have been widely used in the pharmaceutical development for poorly soluble drugs. However, the synergistic effects due to the integration of these two technologies have not been well investigated. The aim of this study is to develop a nano-sized cocrystal of phenazopyridine (PAP) with phthalimide (PI) to enhance the release rate and oral bioavailability of PAP. A PAP–PI nano-cocrystal with particle diameter of 21.4 ± 0.1 nm was successfully prepared via a sonochemical approach and characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and dynamic light scattering (DLS) analysis. An in vitro release study revealed a significant release rate enhancement for PAP–PI nano-cocrystal as compared to PAP–PI cocrystal and PAP hydrochloride salt. Further, a comparative oral bioavailability study in rats indicated significant improvement in C max and oral bioavailability (AUC 0 − ∞ ) by 1.39- and 2.44-fold, respectively. This study demonstrated that this novel nano-cocrystal technology can be a new promising option to improve release rate and absorption of poorly soluble compounds in the pharmaceutical industry.
研究领域:
药剂学
·
药物递送
·
纳米医学
·
药物代谢
·
晶体工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Wenqiang Hu,Wenbin Fu,Samik Jhulki,Liang Chen,Aashray Narla,Zhijian Sun,Fujia Wang,Alexandre Magasinski,Gleb Yushin
Poor heat/flame-resistance of polyolefin (e.g., polyethylene and polypropylene) separators and high flammability of organic electrolytes used in today's lithium-ion batteries (LIBs) may trigger rare yet potentially catastrophic safety issues. Here, we mitigate this challenge by developing a heat-resistant and flame-retardant porous composite membrane composed of polyetherimide (PEI) and Al 2 O 3 nanowires (NWs). The membranes are fabricated based on an industrially scalable non-solvent-induced phase separation process, which results in an intimately interconnected porous network of Al 2 O 3 NWs and PEI . The produced composite membranes exhibit excellent flexibility, thermal stability, and flame-retardancy. Importantly, the composite membranes exhibit minimal thermal shrinkage and superior tensile strength (16 MPa) at temperatures as high as 200 °C, significantly exceeding the performance of conventional polyolefin separators. Compared with commercial separators, their superior wettability and higher ionic conductivity (by up to 2.4 times) when filled with the same electrolyte, larger electrolyte uptake (∼190 wt.%), as well as improved cycle and rate performance demonstrated in LiNiMnCoO 2 (NCM)-based LIBs make them attractive choices for a variety of electrochemical energy storage devices.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子科学
·
纳米技术
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2011
·
IF 2.13
Xin Tian,Zhengping Dong,Yifan Huang,Jiantai Ma
In this work, molecular logic element modified multifunctional silica nanoparticles having high magnetization have been successfully prepared. These multifunctional nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Elementary analysis, X-ray powder diffraction (XRD) and Vibrating sample magnetometer (VSM). The characterization datum indicated that the organic ligand was successfully grafted on the surface of the magnetic silica nanoparticles . The fluorescent changes of the hybrid material upon the addition of cations (H + , F − and their mixture) is utilized as an INHIBIT logic gate at the molecular level, using the fluorescence intensity signal as output.
研究领域:
纳米医学
·
生物传感器
·
分子诊断
·
化学生物学
·
智能材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 58
·53319-53323
·
IF 3.289
Tiantian Gu,Min Zhou,Mengyun Liu,Kangli Wang,Shijie Cheng,Kai Jiang
A polyimide–MWCNT composite (PNP@CNT) synthesized from 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTCDA) and phenylene diamine (PDA) was investigated as a novel anode for aqueous Na-ion batteries. This composite demonstrates a high reversible capacity of 149 mA h g−1 at quite a low potential of −0.65 V (vs. SCE), superior rate capability and long-term cycling stability. The feasibility of PNP@CNTs in aqueous Na-ion full batteries is also confirmed in conjunction with the Na0.44MnO2 cathode, possibly serving as a high performance aqueous Na host anode for large-scale electric energy storage applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
·
纳米生物技术
·
酶工程
·
生物材料
·
分析化学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Shengguo Zhou,Wentao Li,Wenjie Zhao,Chao Liu,Zhiwen Fang,Xiulei Gao
As one of the youngest graphene derivative, fluorinated graphene (FG) with excellent mechanical strength and lubricity was incorporated into polyimide polymer (PI) to strengthen the comprehensive performance of nanocomposite . This article gives a detailed characterization to investigate the tribological behaviors of PI/FG nanocomposite films under different friction conditions including both of dry sliding and seawater lubrication . Firstly, the chloroform-treated FG was proved to be stably dispersed in the PI matrix . Subsequently, mechanical properties, thermal stability and tribological properties of PI/FG nanocomposite films were greatly improved. Finally, analysis of the reasons for the significant improvement in wear resistance from the viewpoint of thermal, mechanical properties and the evolution of friction products. Meanwhile, the transfer of FG from polymer matrix to frictional duality was revealed during tribological testing. The above results suggest the potential application of FG in the field of reinforcing polymer friction properties.
研究领域:
材料科学
·
高分子材料
·
表面工程
·
摩擦学
·
纳米复合材料
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Fei Xu,Hongtao Wang,Mengyi Wu,Jiangsai Nan,Ting Li,Shun-an Cao
Redox-active organic materials are potential cathode materials for material-sustainable and environment-friendly Li-ion batteries. As is one of the most prominent features for organic compounds, isomerism has a significant influence on their properties. Herein, we synthesize two isomeric pairs of poly(anthraquinonyl imide)s ( PAQI s) by a simple one-pot reaction, and investigate their electrochemical properties as Li-ion battery cathodes by cyclic voltammogram and galvanostatic discharge/charge cycling. The PAQI materials exhibit a high reversible capacity of 202 mAh g −1 and a stable cyclability with 80% capacity retention over 200 cycles, and a remarkable rate performance, suggesting a potential feasibility of these organic cathode materials for high-capacity Li-ion batteries. The discharge/charge potentials of these PAQI s are slightly lower than the monomers . A further comparison of these four PAQI s indicates the isomerism plays a significant role in the electrochemical performance of these organic electrode materials .
研究领域:
电化学
·
材料科学
·
能源存储
·
有机电极材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·2982-2991
·
IF 2.137
Zhiyong Zhang,Miaojun Xu,Bin Li
The polymethacrylimide/silicate (PMI/silicate) composites were successfully prepared from the monomers of acrylonitrile (AN) and methacrylic acid (MAA) via the monomer in situ intercalation polymerization and free foaming. The formation of imide groups was monitored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results of FTIR and XPS indicated that the imide groups were gradually formed and cyano groups were dwindling but still existed during foaming and thermal treatment. The thermogravimetric analysis results revealed that the thermal stability of the PMI/silicate composites was improved, the rate of thermal degradation was reduced, and the residue was increased because of the addition of silicates. The results of dynamic mechanical analysis revealed that the rigidity and the glass transition temperature of the composites were improved. The limit oxygen index (LOI) and cone calorimeter (CONE) test showed that the fire-retardant properties were improved because of the barrier effect of silicates. The cell morphologies of the PMI/silicate composites were characterized by scanning electron microscopy (SEM), and the results showed that the silicate particles were distributed on the cell walls, but the cells slightly cracked. The mechanical properties were measured by tensile, flexural, and compressive strength. The mechanical strength, especially flexural strength, was significantly improved. The flexural strength of PMI/MMT, PMI/kaolin, and PMI/talc containing 8 wt% silicates was improved to 172%, 240%, and 233%.
研究领域:
高分子材料
·
复合材料科学
·
材料化学
·
防火材料
·
多孔材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）