CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2018
·
IF 2.795
Mengjie Sun,Meng Li,Pin Wang,Xu Zhang,Cuiming Wu,Yonghui Wu
Anion exchange membranes are prepared by phase inversion of P84 co -polyimide to obtain porous structure, and then chemically modified by branched polyethylenimine. The porous membranes are compared with a dense P84 membrane. The dense membrane is hydrophobic with large area resistance (>85 Ω cm 2 ), while the porous membranes are hydrophilic with low area resistance (2.4–3.5 Ω cm 2 ), lower than that of commercial membrane CJMA-3 (6.0 Ω cm 2 ). The ion exchange capacities are in the range of 0.83–0.86 mmol/g and the water uptake values are 90–130%, both of which are higher than those of dense P84 membrane and CJMA-3 membrane (0.5–0.6 mmol/g; 15–20%). The P84 co -polyimide membranes are utilized in bipolar membrane electrodialysis (BMED) process to produce N -2-hydroxyethylpiperazine- N ′-2-ethanesulfonic acid (HEPES). The porous membranes can decrease the transport resistance of HEPES − ions and yield high recovery ratio and current efficiency, while the dense membrane is unsuitable for BMED . The output of HEPES is increased significantly if the membranes have finger- or tear-like pores, as well as higher ion exchange capacity. The HEPES − recovery ratios are 52.3–61.6% after running 6 h under 40 V, which are higher than that of membrane CJMA-3 (46.5%). The current efficiency can reach up to 86.1% and the energy consumption is only 3.92 kWh/kg by using the optimal porous membrane M-1, which are better than membrane CJMA-3 (65.5%, 5.15 kWh/kg). Hence, the porous membranes have high potential for producing organic acid with high molecular weight.
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高影响因子
Polymers
·
2022
·Vol. 14
·期 24
·5483
·
IF 4.967
Changqing Yang,Chenghai Ma,Duoping Zhang,Zhiang Luo,Meitong Zhu,Binhao Li,Yuanyuan Zhang,Jiawei Wang
In this study, a novel direct Z-scheme SnS2quantum dots/sulfur-doped polyimide (SQDs/SPI) photocatalyst was firstly fabricated by an in situ crystallization growth of SnS2quantum dots on sulfur-doped polyimide through a facile hydrothermal method. The photocatalytic hydrogen production activity of 5SQDs/SPI samples reached 3526 μmoL g−1in the coexistence of triethanolamine and methanol used as hole sacrificial agents, which is about 13 times higher than that of SPI under the same conditions and 42 times higher than that of SPI only as a hole sacrificial agent. The improvement can be related to the direct Z-scheme charge transfer in the tight interface between SQDs and SPI, which promoted rapid separation and significantly prolonged the lifetime of photoexcited carriers. The Z-scheme charge transfer mechanism was proposed. This discovery comes up with a new strategy for the development of an efficient, environmentally friendly, and sustainable sulfide quantum dots/polymer non-noble metal photocatalyst.
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高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2020
·Vol. 60
·期 5
·1044-1053
·
IF 1.917
Yang Yang,Jiming Gao,Ting Lei,Jun Yang,Jin Wang,Jie Liu
Polyimide (PI) composites with mixed fillers of BN flakes and SiC whiskers exhibit enhanced thermal conductivity and mechanical properties. In order to improve dispersion and interaction of these mixed fillers within the PI matrix, BN flakes were modified by a titanate coupling agent while SiC whiskers were oxidized at 750°C for 60 minutes to produce SiC @SiO 2 followed by silane coupling agent modification. PI composites reached a maximum thermal conductivity of 0.95 W/m K at volume fraction of mixed fillers of 27.6 vol% when the weight ratio of BN flakes to SiC @SiO 2 whiskers was 1:4. The enhanced thermal conductivity is likely attributed to the formation of heat conductive networks constructed by BN flakes and SiC @SiO 2 whiskers and the improved interfacial affinity between fillers and matrix. The optimized Nielsen-mold confirms the distribution and morphology of fillers affect the thermal conductivity of PI composites. In addition, SiC whiskers enhanced the mechanical property of PI composites and the influence of fillers on the mechanical property was further elaborated.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 6
·4743-4751
·
IF 2.22
Wang Runfei,Cai Peizhi,Xu Wei,Tan Ruiqin,Shen Wenfeng,Wang Zhaozhao,Chen Guofei,Huang Jian,Fang Xingzhong,Song Weijie
In the past years, transparent film heaters (TFHs) based on silver nanowires (AgNWs) have attracted much attention because of their high transmittance, excellent flexibility, and great thermal response. In this paper, we fabricated flexible TFHs with a sandwich structure composed of Ga-doped ZnO (GZO) and AgNWs on the colorless polyimide (cPI) substrate. The optimized hybrid film exhibited a sheet resistance of 14.6 Ω sq −1 with a transmittance of 79%. Excellent thermal uniformity and heating stability of TFHs were demonstrated. The thermal response tests of the GZO/AgNW/GZO/cPI TFHs showed high saturation temperature (~ 176 ℃) with low input voltage (~ 6 V), fast response time (~ 15 s), and stable heating performance. These results indicate that the flexible TFHs with a GZO/AgNW/GZO sandwich structure have broad potential applications in flexible electronic devices.
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高影响因子
JOURNAL OF POWER SOURCES
·
2020
·
IF 8.247
Hui Peng,Shengliang Qi,Qian Miao,Rui Zhao,Yipu Xu,Guofu Ma,Ziqiang Lei
Holey carbon nanosheets provide unique in-plane pores and abundant interlayer channels, which facilitates the penetration and transmission of ions and significant application in the energy storage. However, rational design and fabrication of holey carbon nanosheets with optimized morphology and porosity remains a challenge. Herein, the nitrogen-doped holey carbon nanosheets (N-HCNs) have been prepared via one-step activation and self-generated template assisted carbonization route using “bottom-up” self-assembled polyimide (PI) nanoflowers as carbon precursor and ethylenediaminetetraacetic acid disodium zinc salt hydrate (EDTA-Na 2 Zn) as activating agent and self-generated template. The N-HCNs demonstrates an integral nanoflowers structure with intertwined and holey carbon nanosheets, which would benefit for the transport of ions and electrons, resulting in a satisfactory specific capacitance of 205 F g −1 at a current density of 0.5 A g −1 . More important, a symmetric aqueous supercapacitor assembled based on N-HCNs electrodes carries a wide operating voltage of 2.0 V, possesses high energy density of 17.92 Wh kg −1 at a power density of 500 W kg −1 , along with outstanding cycling stability. The present work proposes an affordable strategy to design novel porous carbon materials with controlled morphology for advanced energy storage and conversion.
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高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Rui Zhang,Jingjing Xue,Yuan Li,Bing Cao,Pei Li
To suppress pore collapsing and selective layer thickening of Poly (pyromellitic dianhydride-co-4,4’-oxydianiline) (PMDA-ODA) nanofiltration (NF) membrane during imidization, we proposed a novel two step method. Specifically, a PMDA-ODA polyamic acid (PAA) polymer dope was cast on top of a non-woven polyester fabric and then underwent non-solvent induced phase inversion to form a PMDA-ODA PAA membrane. The membrane was subsequently dried by solvent exchange and chemically imidized to form PMDA-ODA PI membrane. Compared with the thermally imidized PMDA-ODA PI membrane, which had a thick selective layer of 14.5 μm and pure water permeability of 1.5 L/(m 2 ·h·bar), membrane fabricated using the new method had a thinner selective layer of 1.04 μm and 7 times higher pure water permeability of 10.4 L/(m 2 ·h·bar) without losing rejections. Other than that, the NF membrane also showed good separation properties in organic solvent systems. It showed rejections of 87%~95% to Rose Bengal in DMF, THF, and DMSO, with stable permeabilities of 6.1–8.0 L/(m 2 ·h·bar), at a trans-membrane pressure of 20 bar for at least 24 h. Therefore, the PMDAODA PI membranes had great potential for NF in both water and organic solvent systems.
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高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2025
·
IF 9.8
Ru Wang,Huanyu Xu,Guiyu Chu,Zhuguang Nie,Yanmeng Peng,Zhiyue Zhao,Fengjiao Jiang,Mingyu Jiang,Shuhua Qi,Rumin Wang
Polymer-based aerogels are the primary choice for many researchers developing multifunctional materials with excellent electromagnetic wave (EMW) attenuation capabilities. Based on the dielectric/magnetic synergistic loss mechanism, a structure-function integrated strategy was employed to construct CoFe 2 O 4 /carbon nanofibers/polyimide (CoFe 2 O 4 /CNFs/PI) composite aerogels with multidimensional heterogeneous structures. The composite aerogels were assembled from CoFe 2 O 4 nanoparticles, CNFs, and polyamic acid salt molecular chains by directional freeze-drying. The three-dimensional conductive skeleton of CNFs/PI aerogel provided conduction loss, interface polarization, dipole polarization, and multiple reflection and scattering of EMW, which synergized with the magnetic loss provided by the magnetic filler CoFe 2 O 4 to produce powerful attenuation capabilities. By adjusting the CoFe 2 O 4 content to optimize impedance matching, CoFe 2 O 4 /CNFs/PI-2 aerogel exhibited outstanding EMW absorption performance with a minimal reflection loss of -65.5 dB. At a low thickness of 2.17 mm, the maximal effective absorption bandwidth reached 6.08 GHz, successfully covering the entire Ku band and part of the X band. Furthermore, the oriented porous structure of composite aerogels endowed them with lightweight (density of 0.085 g/cm 3 ), superior anisotropic mechanical response, and excellent thermal insulation performance. These properties provide a solid foundation for electromagnetic protection in complex environments and aerospace applications.
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·Vol. 13
·期 47
·41354-41364
·
IF 9.5
Shaoyan Zhang,Bing Xie,Haishan Xu,Jinqiao Yi,Kun Guo,Haibo Zhang,Tianyu Li
Polymer film capacitors are vital for power electronic systems due to their ultrafast charge–discharge capability, high power density, mechanical flexibility, and lightweight nature. However, achieving both high discharge energy density (Ud) and high energy-storage efficiency (η) in polymer dielectrics remains a major challenge due to the intrinsic trade-off between permittivity, electric polarization, and breakdown strength. In this study, we have designed bilayer heterogeneous nanocomposites (BHNs) that integrate a linear polyimide (PI) layer—offering low dielectric loss and high breakdown strength—with a ferroelectric P(VDF-CTFE) matrix embedded with dopamine-modified BaTiO3 nanowires (dopa@BT NWs), which imparts high polarization. By precisely tuning the thickness of each layer and the interfacial charge accumulation, we activate synergistic interfacial polarization and a breakdown hindrance effect. More importantly, we propose the concept of a “threshold concentration of interfacial space charge”, which governs the critical charge density required to maximize performance without triggering dielectric instability. As a result, the optimized BHNs (0.3 vol% dopa@BT NWs/P(VDF-CTFE)-PI, whose thicknesses are 4 µm and 8 µm, respectively) exhibit a significantly enhanced Ud of up to 11.1–14.1 J cm−3 and a high η of 72–86%, substantially surpassing conventional single-layer configurations. This work not only delivers promising candidates for advanced dielectric energy-storage applications but also introduces a physically grounded design model that offers guidance for next-generation high-performance polymer-based capacitors.
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DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2026
·
IF 7.3
Shengrui Zhou,Li Zhang,Guan Wang,Bilal Iqbal Ayubi,Rakhmonov Ikromjon Usmonovich,Junpeng Ji
Fluorinated polyimide (FPI) is widely used in high-frequency electronics and aerospace insulation applications owing to its low dielectric loss and excellent stability; however, the degradation behavior and regulatory mechanisms of its high-frequency insulation performance after atomic oxygen (AO) erosion remain unclear. In this study, FPI/POSS composite films with different contents of polyhedral oligomeric silsesquioxane (POSS) were prepared. An AO ground-simulated erosion system was employed to evaluate the protective effectiveness of POSS on FPI and its underlying mechanisms. Combined with vacuum high-frequency partial discharge testing and a partial least squares (PLS) regression model, the effects of AO erosion and material structural regulation on the evolution of insulation lifetime were systematically investigated. The results show that pure FPI exhibits pronounced surface roughening and oxidative erosion after AO bombardment, whereas the introduction of POSS induces the in-situ formation of a dense SiO 2 passivation layer, effectively suppressing further polymer etching. Meanwhile, the FPI/POSS system demonstrates a higher discharge inception voltage, lower dielectric loss, and a longer insulation lifetime. This work provides a new perspective for evaluating insulation reliability and optimizing the structural design of polyimide materials for space service environments.
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高影响因子
POLYMER
·
2026
·
IF 5.1
Yingtao Li,Tao Zhang,Jingxing Gui,Feiyue Zhou,Lixuan Yang,Yuxuan Ma,Baojiang Liu,Dan Yu,Wei Wang
Composite aerogel fabric with integrated infrared stealth and strain-sensing functionalities was fabricated by a highly porous Polyimide (PI) aerogel substrate via directional freeze-assisted wet spinning combined with an ice-templating method. After interfacial modification with polydopamine on the weaved aerogel fabric, MXene and gallium-indium-tin liquid metal (LM) were ultrasonically emulsified and then loaded on the aerogel fabric under ice-water bath conditions. Characterization results show that the porous PI substrate exhibits a low thermal conductivity of 0.03546 W m −1 K −1 , and the composite fabric achieves an infrared emissivity as low as 0.298. Leveraging the synergistic effect of thermal insulation from the substrate and low radiation from the conductive layer, the fabric enables stable infrared camouflage in the temperature range of 50-100 °C. COMSOL simulation of heat transfer in PIMLM fabric confirms the passive cooling effect effectively lowers the thermodynamic temperature of the fabric surface, providing crucial support for its wide-temperature-range infrared stealth capability. In sensing tests, the sample demonstrates a response time of 122 ms and a recovery time of 328 ms, along with excellent signal reproducibility under multilevel strain and various tensile rates, enabling real-time monitoring of human limb movements. This fabrication approach provides a feasible strategy for the development of multifunctional wearable stealth sensing fabrics.
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高影响因子
Journal of Energy Storage
·
2026
·
IF 10.7
Jiachen Lei,Jing Li,Yu Luo,Jingyuan Wang,Hongli Liu
Increasing power density in electronics renders thermal management critical. However, traditional materials with singular thermal functions fail to withstand complex thermal environments, while existing multi-layered composites often suffer from weak interfacial adhesion and leakage of liquid phase change material (PCM). To address the challenges, a bilayer phase change composite polyimide (PI) aerogel featuring orthogonal pore channels is constructed via directional freezing. It integrates a PI insulation layer with an ultralow thermal conductivity of 0.032 W m −1 K −1 and a polyethylene glycol (PEG)-loaded graphene oxide (GO)/PI dissipation layer with a latent heat of 174.9 J g −1 . To ensure strong interfacial performance, a co-imidization strategy using chemically homologous precursors is employed to create a dense and interlocked interface, which achieves a tensile strength of 20.8 MPa and effectively prevents liquid PEG leakage. As for the modulated thermal management of batteries, the surface temperature of the modulated battery achieves a maximum reduction of 38 °C under normal working conditions, while the adjacent battery remains below 50 °C for 2.5 h under the extreme condition of thermal runaway at 200 °C. The bilayer phase change composite aerogel demonstrates great potential for practical applications, especially for high-power batteries and electronic equipment.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2026
·
IF 2.8
Xiao Zhen,Chen Jianfeng,Li Wenkang,Yu Shaoxiong,Gu Jiatao,Yang Wutao,Wang Yijue,Xu Rui,Xia Yang,Zhang Lihui,Wang Bingjia
Carbon-based conductive polymer composites have attracted widespread attention due to their excellent flexibility, ultra-lightweight characteristics, cost-effectiveness, and tunable electrical performance. However, their practical applications are severely restricted by inherent limitations, such as the inability to achieve sustainable high temperatures under low driving voltages, inadequate thermal stability at high temperatures, and uneven heat distribution. To overcome these intractable issues, we designed a series of glass powder/carbon black@polyimide (GP/SP@PI) composite electrothermal films by a practical and scalable slurry coating method. In this regard, the incorporation of low-melting-point glass powders not only significantly increases the maximum operating temperature over 200°C, but also substantially enhances the thermal stability and flame retardancy. Upon ignition, the GP/SP@PI composite electrothermal films self-extinguish within 4 s without sustained combustion or droplet formation. Moreover, as a thin-film electric heater, the optimized sample (PI-65) exhibits rapid temperature response, efficient electrothermal conversion, and excellent heating reliability. By virtue of these advantages in terms of low-voltage operability, high-temperature stability, and inherent safety, these GP/SP@PI composite electrothermal films are employed as a thin-film electric heater to boil water for a simplified practical application. Notably, the PI-65 sample successfully heats 10 ml water from room temperature to 99.6°C within 4 min, confirming the high feasibility of application in household appliances. This work provides innovative insights into the rational design of carbon-based composite electrothermal films with high operating temperature as well as superior reliability for integrated thin-film electric heaters. Moreover, the method is simple and can be adopted in industrial applications. Graphical
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