COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2018
·
IF 4.514
Hao Feng,Xinliang Fang,Xiaoyun Liu,Qibing Pei,Zhong-Kai Cui,Shifeng Deng,Jinlou Gu,Qixin Zhuang
This study reports the synthesis and characterization of reduced polyaniline decorated reduced graphene oxide/polyimide (RGO@R-PANI/PI) nanocomposite films with enhanced dielectric properties and thermostability. The steric effects of R-PANI decorated on the surface of RGO not only prevented the aggregation of RGO but also improved the dispersion of RGO@R-PANI nanosheets in the PI matrix, leading to higher dielectric constant (ε) and lower dielectric loss (tanδ) of the RGO@R-PANI/PI nanocomposite films than those of the RGO/PI nanocomposite films. The highest dielectric constant (25.84) was observed in the 20 wt% RGO@R-PANI/PI nanocomposite film (the mass fractions of RGO was 3.44%) with a low dielectric loss of 0.11 at 1 kHz. Furthermore, the 5 wt% weight loss temperature of the 20 wt% RGO@R-PANI/PI nanocomposite films was 480 °C, indicating the nanocomposite films are good candidates for dielectric materials under extreme temperature.
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高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Yang Pu,Shuang Zhu,Pohui Wang,Yuqin Zhou,Pan Yang,Sensen Xuan,Yaping Zhang,Hongping Zhang
A novel branched sulfonated polyimide/molybdenum disulfide nanosheets (bSPI/MoS 2 -ns) composite membrane was fabricated for vanadium redox flow battery (VRFB) application. Scanning probe microscope (SPM) and field emission-scanning electron microscope (FE-SEM) images verify the successful exfoliation of monolayer and a few layers of MoS 2 nanosheets. X-ray diffraction (XRD), attenuated total reflection-fourier transform infrared spectrometer (ATR-FTIR) and FE-SEM results demonstrate that bSPI, bSPI/MoS 2 -ns and bSPI/MoS 2 nanopowders (bSPI/MoS 2 -np) membranes are successfully prepared. Both thermogravimetric analysis/differential thermogravimetry (TGA/DTG) and ex-situ chemical stability testing results confirm bSPI/MoS 2 -ns membrane has improved thermal and chemical stabilities in contrast with pristine bSPI membrane. The bSPI/MoS 2 -ns membrane owns high proton conductivity (5.04 × 10 −2 S cm −1 ) and extremely low vanadium ion permeability (0.65 × 10 −7 cm 2 min −1 ), leading to its highest proton selectivity (7.75 × 10 5 S min cm −3 ) among all the membranes tested. Besides, during 500 times cycle charge–discharge test, the coulombic efficiency, energy efficiency and discharge capacity retention of VRFB using bSPI/MoS 2 -ns membrane are higher than or comparable to those of VRFB using Nafion 117 membrane. And the surfacial morphological integrity of bSPI/MoS 2 -ns membrane maintains better than reported pristine bSPI membrane after long-time VRFB usage. Above results indicate that the as-prepared bSPI/MoS 2 -ns membrane has great potential for VRFB application.
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高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Xin Li,Jin Wang,Yibo Zhao,Xuetong Zhang
Aerogels have been widely used in the fields like thermal insulation, energy storage, environmental remediation, catalysis, drug release, sensor, and cosmic dust collection, etc. Hydrophobic functionalization not only determines the surface energy and basic physical properties of the target aerogels but also be critical for their long-term stability due to their highly open-porous structures. However, there is still lack of facial and versatile methodologies for the hydrophobic functionalization of aerogels, especially for the nonsilica ones. Herein, two efficient fluorine-free strategies were developed to synthesize various hydrophobic and even superhydrophobic polyimide (PI) aerogels. First, superhydrophobic PI aerogels with contact angle higher than 150° were fabricated by the segregation self-assembly process between poly[4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride)-co-p-phenylene diamine] and poly[biphenyl-3,3′,3,4′-tetracarboxylic dianhydride-co-2,2′-dimethylbenzidine] (poly(BPDA-DMBZ)). These PI aerogels exhibited a lotus effect that water droplets could not wet the surface but could easily roll off. Second, various hydrophobic PI aerogels, including the well-documented superhydrophilic PI aerogels derived from DMBZ–BPDA and 4,4′-oxydianiline–BPDA, were synthesized by the density-induced hydrophilicity–hydrophobicity transition approach. These PI aerogels exhibited a petal effect that water droplets on the aerogel surface appeared spherical in shape, which could not roll off even when the aerogel was turned upside down. These two reported strategies might open new and straightforward ways to hydrophobic functionalization of other polymeric aerogel systems.
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PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 39
·47991
·
IF 2.188
Dekang Cheng,Huan Wang,Bin Liu,Shan Wang,Yang Li,Yushuang Xia,Chuanxi Xiong
Flexible dielectric materials with high electric energy density and high-temperature resistant characteristic are of great importance for modern electronics and electrical systems. Herein, two-dimensional molybdenum disulfide (MoS 2 ) nanosheets were efficiently produced via liquid-phase exfoliation and then incorporated into polyimide (PI) to prepare MoS 2 /PI dielectric nanocomposites. Compared to the pristine PI, MoS 2 /PI nanocomposite films exhibited much larger dielectric permittivity while their dielectric losses still maintained relatively low levels. On the other hand, the Weibull breakdown strength of these nanocomposite films initially increased and then decreased with the increase in the MoS 2 content and gave rise to a maximum value of 395 MV m −1 at 1 vol % loading. Combination of the improved dielectric permittivity and breakdown strength makes the MoS 2 /PI nanocomposite film with 1 vol % MoS 2 possess an elevated energy density of about 3.35 J cm −3 . Moreover, good tensile and thermal properties of the nanocomposite films hold great promise for their applications in high-temperature and harsh conditions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47991.
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高影响因子
ACS Applied Polymer Materials
·
2019
·
IF 0
Chao Qian,Tianwen Zhu,Weiwen Zheng,Runxin Bei,Siwei Liu,Dingshan Yu,Zhenguo Chi,Yi Zhang,Jiarui Xu
Surface hydroxylation was implemented on CaCu3Ti4O12 (CCTO) particles to improve their interface compatibility and dispersibility in polyimide matrix. The surface hydroxylated CCTO fillers (CCTO–OH) were obtained by treating the CCTO particles in the mixed solution of H2SO4 and H2O2. The experimental results showed that the CCTO–OH/polyimide (PI) composite films had higher dielectric permittivity and lower coefficient of thermal expansion (CTE) compared to those of the CCTO/PI composite films, which were mainly attributed to the good dispersion of CCTO–OH particles and the enhanced interfacial polarization between CCTO–OH particles and PI chains. Among these CCTO–OH/PI composite films, the composite film with 40 vol % CCTO–OH particle loading exhibited the highest dielectric permittivity (76.9, 102 Hz), and a low dielectric loss (0.2, 102 Hz) was maintained. The maximum discharge energy density of the CCTO–OH/PI composite film with 25 vol % CCTO–OH reached 1.31 J/cm3, which was almost twice that of pure PI (0.63 J/cm3). Further, the prepared CCTO–OH/PI composite films had excellent heat resistance and low CTE. The high-k property of the CCTO–OH/PI composites remained stable up to 300 °C, which is probably the most heat-resistant dielectric material reported in the literature and is absolutely critical for the manufacture of electronic devices facing extreme conditions.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 12
·46029
·
IF 1.86
Yao Yao,Guangcheng Zhang,Jianwei Li,Aifeng Wang,Xuetao Shi
A series of thermal insulation, acoustic absorption isocyanate-based lightweight polyimide (PI) foams with 4,4′-diaminodiphenyl ether (ODA) units were prepared from polyaryl polymethylene isocyanate (PAPI) and the esterification solution derived from pyromellitic dianhydride (PMDA) and ODA. The structures and properties of the PI foams prepared with different molar ratio of ODA/PMDA were investigated in detail. The results show that the ODA units have great influence on the foam properties. With the increase of the ODA units, the density decreases firstly and then increases. When the molar ratio of ODA/PMDA is 3/10, the foam reaches the minimum density (13.7 kg/m 3 ). Moreover, with increasing the ODA units, the acoustic absorption properties increase firstly and then decrease owing to the variation of the average cell diameter of the PI foams. All PI foams show excellent thermal stability, and the 5% and 10% weight loss temperature are in the range of 250–270 °C and 295–310 °C, respectively. In addition, the PI foams present low thermal conductivity and thermal diffusivity. Furthermore, the mechanical property was also evaluated and the compressive strength of the PI foams is in the range of 33.0–45.7 kPa. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46029.
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yang Xia,Qiyue Wang,Yaning Liu,Jun Zhang,Xinhui Xia,Hui Huang,Yongping Gan,Xinping He,Zhen Xiao,Wenkui Zhang
The replacement of traditional liquid electrolytes with polyethylene oxide (PEO) based composite polymer electrolytes (CPEs) is an important strategy to address the current flammability and explosiveness of lithium batteries since PEO CPEs have high flexibility, excellent processability and moderate cost. However, the insufficient ionic conductivity and inferior mechanical strength of PEO CPEs do not suit the operating requirements of all-solid-state lithium metal batteries at room temperature. Herein, three-dimensional (3D) framework composed of interweaved high-modulus polyimide (PI) nanofibers along with functional succinonitrile (SN) plasticizers are employed to synergistically reinforce the ionic conductivity and mechanical strength of PEO CPEs. Impressively, benefitting from the synergistic effects of 3D PI framework and SN plasticizer, PI-PEO-SN CPEs exhibits high ionic conductivity of 1.03 × 10 −4 S cm −1 at 30 °C, remarkable tensile strength of 4.52 MPa, and superior Li dendrites blocking ability (>400 h at 0.1 mA cm −2 ). Such favorable features of PI-PEO-SN CPEs endow LiFePO 4 /PI-PEO-SN/Li solid-state prototype cells with high specific capacity (151.2 mA h g −1 at 0.2 C), long cycling lifespan (>150 cycles with 91.7 % capacity retention), and superior operating safety even under bending, folding and cutting harsh conditions. This work will pave the avenues to design and fabricate new high-performance PEO CPEs for the high energy density and safety all-solid-state batteries.
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PubMed
高影响因子
POLYMER
·
2023
·
IF 4.6
Yaqi Li,Yongjian Cao,Silong Wu,Yuanlai Ju,Xiaohua Zhang,Canhui Lu,Wei Sun
Polyimide (PI) films have been extensively used in the field of microelectronic as insulating materials. With the rapid development of microelectronic devices towards miniaturization and large power, the development of low dielectric properties of PI materials has attracted more and more attention. In this study, the breath figure (BF) process was used to prepare single-layered and multi-layered microporous PI films, for obtaining the low dielectric properties . The BF porous structure of PI film was successfully constructed by two implementing strategies, i.e., solution casting for direct preparation of PI film and solvent treatment upon pre-shaped PI film for in-situ pore-formation. By changing solution concentration, environmental humidity and temperature, efficient manipulation of the pore morphology of the film both on the surface and in the bulk layer was achieved. Such multi-layered porous BF structure has been proved to significantly lower the dielectric constant of PI film, from 3.7 of non-porous film to 1.7 of porous film. In order to further expand the application range of BF microporous PI film, both ways of alkali treatment and thermal oxidation were taken for the cross-linking of the porous PI films, greatly improving the solvent resistance of the film. The original porous morphology was completely retained, ensuring that the low dielectric properties were not affected. This is the first report on the preparation of multi-layered microporous low dielectric PI films by BF process.
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高影响因子
POLYMER INTERNATIONAL
·
2023
·Vol. 72
·期 6
·569-577
·
IF 3.2
Weilian Wu,Shiqing Lai,Hongchao Niu,Chanjuan Liu,Zengfang Huang,Li Zhou,Xiaohua Huang
Three novel fluorinated polyimides (PIs) were synthesized via one-step solution polycondensation from a new diamine monomer, 4-(3-methoxy-4-(difluoromethoxy)phenyl)-2,6-bis(4-aminophenyl)pyridine, and three commercially available aromatic dianhydrides. The solubility, thermal, optical, hydrophobic and gas transport properties of the obtained PIs were investigated. The results demonstrated that these polymers present good solubility in dimethylformamide, N -methylpyrrolidone, dimethylsulfoxide, dimethylacrylamide, CHCl 3 , tetrahydrofuran and CH 2 Cl 2 at room temperature or upon heating. Meanwhile, they displayed excellent thermal properties with glass transition temperature of 261–345 °C, weight loss temperatures at 10% of 518–523 °C as well as char yield of 60–62% at 800 °C in nitrogen atmosphere. Furthermore, the PI membranes have good hydrophobic properties with water contact angle value in the range 90.1–92.0°. Moreover, they show excellent optical properties, with cut-off wavelength ( λ cut-off ) values of 368–381 nm and wavelength values at 80% transmittance ( λ 80% ) of 421–462 nm. The pure gas permeabilities of He, CO 2 , O 2 and N 2 of the PI membranes were measured by the method of constant volume–variable pressure. The PI containing 4,4′-(hexafluoroisopropyl)diphthalic anhydride moiety exhibits the largest molecular chain spacing and free volume, giving the best gas transport performance in this work. Molecular simulation results show that the introduction of fluorine-containing structure and bulky pendant into polymer backbones is beneficial for gas transport. © 2023 Society of Industrial Chemistry.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Lu Liu,Qi Wu,Shunli Wang,Wei Lai,Peijun Zheng,Can Wang,Xin Wei,Shuangjiang Luo
The recovery of helium from natural gas using membranes has attracted substantial attention, while very limited polymers were spun into hollow fibers and evaluated for realistic helium recovery. This work demonstrates the successful preparation of asymmetric and highly helium-selective hollow fiber membranes for the enrichment of helium from natural gas. A novel, aromatic copolyimide was designed and fabricated into hollow fiber membranes (HFMs) via the dry-jet/wet-quench spinning approach. The as-prepared HFMs display a He permeance of 85 GPU and high He-related gas selectivities of 140, 204, 448, and 609 for He/N2, He/CH4, He/C2H6, and He/C3H8 gas pairs, respectively. Particularly, ternary and quaternary mixed-gas permeation results reveal excellent light and heavy hydrocarbon resistance due to the competition between plasticization and gas sorption. The HFMs also demonstrated superior low-temperature gas separation performance and outstanding membrane gas separation stability, rendering them attractive for helium recovery.
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高影响因子
TRIBOLOGY INTERNATIONAL
·
2022
·
IF 5.62
Qi Huimin,Lei Yang,Yu Jiaxin,Zhao Gai,Guo Baogang,Zhou Liang,Zhang Ding
The effect of fullerene carbon (C60) on the tribological performance of polyimide (PI) composites was explored at different temperature conditions. The results demonstrate the addition of 1.0 wt% C60 can greatly enhance the tribological performance of PI/1.0C60. The friction coefficients and wear rates of 0.03/0.07 and 1.0 × 10 −5 /1.6 × 10 −5 mm 3 /Nm can be achieved at − 100 °C/200 °C, respectively, reducing by 86.4%/50.0% and 28.6%/30.1% compared with pure PI. It demonstrated the polymer states influenced the lubricated and loading carry capability of the sliding interfaces at different temperatures. XPS results indicated tribo-oxidation and organic-inorganic chelation reaction dominated the tribofilm growth. Moreover, molecular dynamics simulation showed the C60 enables the shear of PI easily due to the decreased intermolecular forces.
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高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2022
·Vol. 331
·期 4
·1741-1750
·
IF 1.754
Xian Li,Wang Kaikai,Huang Yin,Liu Peidong,An Heng,Yang Shengsheng,Chang Shuquan,Zhang Haiqian
In order to meet the needs of spacecraft for high-performance materials, polyimide (PI)/carbon nanotubes (CNTs) composite films were prepared and their performance changes under the coupling effect of electron beam irradiation/tensile stress were studied. The results showed that the PI/CNTs composite films had excellent mechanical properties and radiation resistance, and can be used as a promising candidate material for space applications.
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高影响因子
危险品化学品经营许可证（带存储）