CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Ke Zhao,Yingbo Chen,Siyu Wei,Meng Wang,Pengfei Li,Hao Li,Xianglin Zhang
With the advent of the 5G era, the demand for heat dissipation using high thermal conductivity (TC) materials is becoming increasingly urgent. The electrical insulation and thermal stability of dielectric polymer composites are also notable in electrical and electronic applications. Nevertheless, the improvement in TC of dielectric polymer composites is typically accomplished at the expense of electrical insulating capabilities. Herein, we fabricated polyimide (PI) composites with ordered structure by combining electrostatic spinning, vacuum filtration deposition and blade-coating. The modified boron nitride nanosheets (mBN) not only enhanced the interaction between filler and PI matrix, but also reduced the interface thermal resistance. Benefiting from the hierarchical structure, the in-plane TC of prepared composite was 17.44 W/mK at 18.79 vol% mBN content, which is 9.6 times higher than that of pure PI. Moreover, the composites were electrically insulating, with the volume resistivity of about 10 13 Ω cm, and exhibited great flexibility, exceptional thermal stability (T HRI ＞ 269 °C), excellent thermal dissipation capability and low dielectric characteristics. In summary, this work offers a novel perspective to design highly thermally conductive composites and these composites have vast application potential in flexible electronic devices or circuits.
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高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Tao Shi,Huan Liu,Xiaodong Wang
To realize highly efficient solar-thermo-electric energy conversion for clean electricity power generation, we have developed a new type of unidirectionally structured magnetic phase-change composite comprising a carbonized polyimide (C–PI)/Kevlar nanofiber (KNF) complex aerogel as a 3D carbon skeleton porous supporting material, CoFe2O4 nanoparticles as a magnetic additive, polyethylene glycol (PEG) as a phase-change material, and polypyrrole as a photothermal absorption coating layer. The as-fabricated C–PI/KNF complex aerogel exhibits a unidirectional microstructure, high porosity, robust skeleton frame, ultralight weight, and high thermal conductance. Featured with such unique structure and characteristics, the complex aerogel can offer an effective heat and electron transfer method to ensure highly efficient solar-thermal conversion and photothermal energy storage of the developed composite. The developed composite exhibits a high latent heat capacity of over 150 J g–1, outstanding shape stability along with a low leakage of 0.2 wt %, good thermal cycling stability, and high photothermal conversion efficiency of 84.8%. Based on the Seebeck effect, a solar thermoelectric generation system (STEGS) was constructed with the hot side coupled with the developed composite and the cold side immersed in air and ice water. Under 2.0 kW m–2 solar irradiation, the developed STEGS in ice water obtained maximum output voltage and current of 259.7 mV and 27.1 mA, respectively, which are significantly higher than those in air. The output power of the developed STEGS in an ice water environment is 50.6% higher than that in air under 4.0 kW m–2 solar irradiation. More importantly, the developed STEGS in ice water continuously generated output voltage and current for about 810 s without solar irradiation thanks to the latent heat release by the PEG component within the developed composite. In addition, the introduction of magnetic CoFe2O4 can accelerate solar-thermal conversion through periodic electron motion by the Néel relaxation or Brownian relaxation. This resulted in an increase in the maximum output voltage and current by 13.7 and 11.5%, respectively, under an alternating magnetic field as a result of the magnetism-accelerated solar-thermo-electric conversion. This study offers an innovative approach for developing PCM-based advanced functional materials for solar energy utilization in clean and sustainable electricity generation.
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PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Long Cheng,Hui Li,Longlong Zhu,Mingyu Wei
Polyimide (PI) , a metal-free conjugated polymer, holds great potential for persulfate (PDS) activation under visible light owing to its tunable electronic structure and chemical stability. However, achieving a rational balance between optical absorption, charge separation, and surface accessibility remains challenging. Here, we systematically investigate the effect of polymerization temperature (250–400 °C) on the optical, structural, and electronic properties of PI and establish its correlation with photocatalytic activity toward Acid Orange 7 (AO7) degradation. The optimized catalyst, PI-325, exhibits an appropriate bandgap of 2.69 eV, a surface area of 4.09 m²/g, and achieves 98.9 % AO7 degradation within 80 min under visible-light irradiation, demonstrating excellent activity, selectivity, and reusability. Mechanistic investigations combining electron-paramagnetic-resonance detection and radical-quenching experiments reveal that visible-light excitation promotes electron transfer from PI to both O 2 and PDS, generating SO 4 • ⁻ and O 2 •- as the dominant reactive oxygen species. Furthermore, Fukui-function analysis identifies the azo (–N = N–) bond of AO7 as the primary reactive site for radical attack, supporting the experimentally observed degradation pathway in which AO7 is transformed into low-toxicity carboxylic acids via sequential oxidation and ring-opening reactions. This integrated experimental-theoretical study demonstrates that polymerization-temperature modulation provides an effective route to optimize the conjugation, crystallinity, and defect structure of PI for visible-light-driven PDS activation, offering new insights into the structure–activity–mechanism relationship in sustainable, metal-free photocatalytic systems.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Youquan Ling,Junjie Liu,Bolin Xiao,Hui Jin,Luxiang Zhao,Yanjiang Bai,Xi Zhang,Mei Liang,Yang Chen,Huawei Zou
In this study, carboxymethyl cellulose (CMC), a polymer abundant in hydroxyl and carboxyl groups, was employed as an interfacial layer between polyimide fibers and EPDM rubber. The formation of hydrogen bonds between CMC and the polyimide fibers facilitated a robust encapsulation of CMC on the fiber surface. Additionally, a greater number of SiO 2 nanoparticles were adsorbed onto the CMC surface through hydrogen bonding and condensation reactions, significantly enhancing the fiber's surface roughness and the matrix's wettability. This strong mechanical interlocking structure markedly improved the interfacial adhesion and mechanical properties of the composites. Specifically, the H pull-out force, tensile strength, and elongation at break increased by 84.8 %, 89 %, and 45 %, respectively, compared to the control samples. In-situ electron microscopy further confirmed that the reinforced interface effectively inhibited crack propagation along the interface. Low-field NMR analysis revealed that the enhanced interfacial bonding restricted the mobility of rubber molecules, contributing to higher strains and stresses during the orientation hardening phase under tension. Moreover, the improved interfacial adhesion and the incorporation of SiO 2 within the interfacial layer also enhanced the ablative resistance and thermal insulation properties. These findings demonstrate that the CMC/SiO 2 encapsulation strategy represents an environmentally friendly, rapid, and efficient interfacial modification method for polyimide fiber-reinforced EPDM insulation materials.
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高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Wenheng Huang,Jun Long,Huiting Li,Liang Chen,Jinchao Li,Qianqian Liang,Xuedan Chen,Zhengjin Yang,Yingze Song,Yaping Zhang
In this work, a new branched trianhydride monomer 1,3,5-tris(4-naphthyloxy-1,8-diacid) phthalic anhydride is established for improving the chemical/dimensional stability and proton conduction of the branched sulfonated polyimide (BSPI) membrane for application in vanadium flow battery (VFB). Compared with linear SPI-60 membrane containing conventional dianhydride monomer 1,4,5,8-naphthalenetetra-carboxylic dianhydride, BSPI-60 membrane exhibits remarkable resistance to vanadium ions , proton conduction and structural stability . Besides, the challenge of simultaneously improving vanadium ions resistance and proton conductance is tackled. The proton selectivity of BSPI-60 membrane achieves 1.11 × 10 5 S·min/cm 3 , which is 2.8 and 2.5 times higher than both SPI-60 (0.39 × 10 5 S·min/cm 3 ) and commercial Nafion 212 (0.44 × 10 5 S·min/cm 3 ) membranes, respectively. At the same time, BSPI-60 membrane exhibits higher coulomb efficiencies (97.2 %–99.3 %) and energy efficiencies (85.6 %–69.5 %) compared those of SPI-60 and Nafion 212 membranes at 100–300 mA/cm 2 . Remarkably, the 500 cycles of BSPI-60 membrane at 140 mA/cm 2 are also stably executed. The internal reasons for enhanced chemical/dimensional stabilities and proton conduction of BSPI-60 membrane are clarified from theoretical calculations with mean square displacement value, fractional free volume and natural bond orbital charge via density functional theory and molecular dynamics simulation . Our study encompasses not only the synthesis of a novel branched trianhydride monomer but also the development of a BSPI membrane with a unique molecular structure specifically designed for VFB applications.
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Tadele Daniel Mekuria,Zhang Chunhong,Liu Yingnan,Diaa El Din Fouad,Keyu Lv,Ming Yang,Yanli Zhou
In this study, 4,4′-methylene diphenyl diisocyanate (MDI) was used as a functionalizing agent to chemically grafting amino-functional groups on the nano-silica surfaces to achieve amino functionalized silica (SiO 2 -NH 2 ) nanoparticles . In situ polymerization technique was employed to fabricate PI/SiO 2 -NH 2 nanocomposite films followed by typical thermal imidization process. The mechanical and thermal properties as well as the water resistance of PI/SiO 2 -NH 2 composites were notably improved as compared to those of the original PI and PI/SiO 2 . The composite films shown a meaningful enhancement in both tensile strength and modulus up to 25.0% and 40.2%, respectively up on the addition of 2–10 wt% SiO 2 -NH 2 into the PI system when compared with the pristine PI. Likewise, the 5% and 10% weight loss temperatures were improved up to about 29.8 and 24.5 °C respectively, in comparison with the ones for pristine PI. The composites also exhibited a remarkably increased T g (glass transition temperatures) values up to 19% when 2–10 wt% SiO 2 -NH 2 nanoparticles were added to the matrix. The nanocomposites also demonstrated an astonishing decrease in water intake reaching up to 77% enhancement as the SiO 2 -NH 2 load in the PI medium increased from 0 to 10% implying that the hydrophobic property of the composite films was highly improved. As compared to the pristine silica particles , the SiO 2 -NH 2 nanoparticles showed excellent improvement in key performances of PI.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Wenzhong Ma,Taiyu Li,Chao Jiang,Peng Zhang,Li Deng,Rong Xu,Qi Zhang,Jing Zhong,Hideto Matsuyama
Pervaporation (PV) performance of polyimide (PI) membranes has been attempted for the recovery of high concentrations of aprotic solvents, such as N, N-dimethyl formamide (DMF) and N, N-dimethylacetamide (DMAc). In this work, we explored the effect of chain structure on the solvent resistance and pervaporation performance of hydrophilic pyromellitic dianhydride (PMDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) based polyimide membranes. According to the Hansen solubility parameters and membrane formation morphologies, we selected five aprotic solvent resistant PI membranes with different chain structures. It was found that the swelling degrees in DMF and DMAc was principally determined by the elasticity modulus of the PI membrane, and was significantly influenced by the polymer chain structure. The flexible linkages (such as –O CH 2 and CH 2 ) suppressed the PI chain packing, which resulted in the d -spacing and fractional free volume ( FFV ) of PMDA based PI membrane was higher than BTDA based PI membrane. BTDA-BZD membrane had the highest elasticity modulus together with the lowest d -spacing value (4.68 Å) due to its symmetric intermolecular interaction and rigid chain structure. PV experiments were conducted with DMF/water and DMAc/water mixtures over a wide range of temperatures (30–60 °C) with 90 wt% solvent concentration. The BTDA based PI (M4) composite membrane showed the highest separating factor around 275 at 30 °C in DMAc solution, which was much higher than in DMF solution (the separating factor is about 70). Furthermore, the chemical and thermal stability test for the PI composite membranes in the presence of the feed solvent under the PV process demonstrated the excellent separation stability in DMAc solution.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 20
·14506-14524
·
IF 2.993
Zhang Yaping,Pu Yang,Yang Pan,Yang Hongyan,Xuan Sensen,Long Jun,Wang Yanlin,Zhang Hongping
Silicon carbide (SiC) was pretreated and functionalized by using α, ω-diaminopropyl polydimethylsiloxane (PDMS) to obtain a novel inorganic filler SiC (PDMS). Then, a series of branched sulfonated polyimide/SiC (PDMS) (bSPI/SiC (PDMS)) composite membranes with different contents of SiC (PDMS) were fabricated for vanadium redox flow battery (VRFB) application. Fourier transform infrared spectra, X-ray diffraction, and field emission scanning electron microscope demonstrate the successful preparation of SiC (PDMS) and bSPI/SiC (PDMS) membranes. The thermogravimetric analysis shows that bSPI/SiC (PDMS)-1.5% membrane has better thermal stability than pure bSPI, bSPI/SiC-1.5%, and Nafion 117 membranes. The ex situ chemical stability test results show that bSPI/SiC (PDMS)-0.5–2.5% composite membranes have better chemical stabilities than pure bSPI membrane. The physicochemical properties of bSPI/SiC (PDMS) membranes, including water uptake, swelling ratio, ion exchange capacity are investigated. Thereinto, bSPI/SiC (PDMS)-1.5% membrane has the highest proton selectivity ( S : 2.99 × 10 5 S min cm −3 ) and was chosen as an optimum VRFB membrane. And the VRFB assembled with bSPI/SiC (PDMS)-1.5% membrane exhibits better battery performance than that assembled with Nafion 117 membrane during 500-time cyclic charge–discharge test at 20–60 mA cm −2 . Above results indicate that as-optimized bSPI/SiC (PDMS)-1.5% membrane has great potential for VRFB application.
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高影响因子
CHEMPHYSCHEM
·
2026
·Vol. 27
·期 14
·e70498
·
IF 2.4
Guanqin Wang,Wenlong Gao,Yuting Han,Xinyu Wang
The development of advanced ion–conducting membranes is crucial for improving alkaline zinc–iron flow batteries (AZIFBs), which face a persistent tradeoff between ion selectivity and conductivity. This work presents a sulfonated poly(ether ether ketone)/polyimide (SPEEK/PI) composite membrane engineered via Lewis acid–base interaction. The specific interaction between the –SO 3 − groups of SPEEK and the –N= sites of PI creates additional cross–linking points within the polymer matrix. This cross–linked structure effectively suppresses membrane swelling and enhances mechanical stability. Consequently, the composite membrane demonstrates superior ion selectivity by significantly hindering the crossover of active species such as [Fe(CN) 6 ] 4− . When applied in AZIFBs, the SPEEK/PI membrane enables a notable improvement in electrochemical performance. The battery achieves a high coulombic efficiency (CE) of 98.3%, an energy efficiency (EE) of 89.8%, and a voltage efficiency (VE) of 91.4% during long-term cycling at 80 mA cm −2 , outperforming devices using pristine SPEEK membranes (CE:95.4%; EE: 86.7%; VE: 90.9%). This study provides a cost-effective and efficient membrane design strategy based on molecular interaction, offering a promising alternative for practical flow battery applications. Graphical The Lewis acid–base interaction between SPEEK and PI effectively reduces the swelling ratio and enhances the mechanical stability of the membrane, contributing to its enchanced ion selectivity. Therefore, the AZIFBs with SPEEK/PI membranes display superior electrochemical performance with higher reversibility and stability.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Manqing Zhao,Yan Wang,Bin Xie,Tengbin Yi,Qiuhong Bai,Hang Zhao,Yang Wang,Luwei Zhang,Zhimin Dang,Yehua Shen
Data-driven screening identifies melamine as optimal precursor for QbPIs. • Star-shaped topology expands HOMO-LUMO gap, introduces deep traps, and stabilizes Ag/dielectric interface. • Topological structure suppresses conduction loss and charge injection, disrupting charge-transport pathways. • QbPI-1.75 achieves 5.39 J/cm 3 at 25 °Cand 3.29 J/cm 3 at 200 °C with high efficiency. • Scalable, cost-effective design provides a platform for high-temperature polymer dielectrics beyond polyimides. The development of high-power electronics demands polymer dielectrics with high thermal stability and dielectric performance. However, most materials suffer performance degradation in harsh environments due to increased electrical conductivity. Herein, a physics-informed data-driven topology-supported precursor screening strategy was proposed to design quasi-branched polyimides (QbPIs) with enhanced energy density ( U e ) and charge-discharge efficiency ( η ) at elevated temperatures. By constructing automated screening workflow, key descriptors involving HOMO-LUMO gap ( Gap ) and dielectric constant ( ε r ) were sufficiently evaluated to form multi-parameter ranking framework, in which melamine was identified as the optimal topological center for constructing QbPIs with tunable topological ratios (0–2.5%). Notably, the resulting star-shaped topological structure effectively regulates charge transport and dielectric behavior through a cooperative mechanism. It increases the Gap , introduces deep-level traps, and stabilizes the Ag/dielectric interface, which together suppress conduction loss and charge injection, effectively disrupting long-range charge-transport pathways. The optimized QbPI-1.75 exhibited outstanding capacitive performance, delivering 5.39 J cm −3 ( U e ) with 94% ( η ) at 25 °C, and retaining 3.29 J cm −3 with 78.41% at 200 °C, far exceeding that of pure PI (1.35 J cm −3 , 87.6% η at 25 °C). This work establishes a fundamental structure-property relationship for topological PIs and provides a facile design strategy applicable to other high-temperature polymer dielectrics. A Physics-Informed Data-Driven Topology-Supported Precursor Screening Strategy screens melamine as the optimal precursor to construct star -shaped all-organic polyimide dielectric films. At 25 °C/200 °C, QbPI-1.75 exhibited breakdown strength 51.58%/32.61% higher than PI and energy densities of 5.39/3.29 J cm −3 , respectively. The star topology enhanced planar stacking to suppress thermal motion, introduced deep traps, and broadened the bandgap, synergistically blocking charge transport and raising the excitation barrier, thus overcoming material bottlenecks for high-temperature capacitive energy storage. This scalable, cost-effective approach is extendable to other polymer systems. Download: Download high-res image (107KB) Download: Download full-size image
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高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Jiang Guo,Yukun Sun,Xinyi Zhao,Jiawei Wang,Honglin Wu,Luo Kong,Wenling Wu,Yuan Fang,Qing Wu,Jianfeng Zhu
Achieving low reflection loss, broad absorption bandwidth and lightweight remains a major challenge for electromagnetic wave absorption (EWA) materials. In this work, the lightweight multifunctional polyimide composite aerogels reinforced with two-dimensional Co-anchored MXene (Co/MXene) and one-dimensional CoFe 2 O 4 -decorated carbon nanofibers (CoFe 2 O 4 /CNF) were successfully prepared for high-performance EWA. The dielectric and magnetic losses were significantly improved due to the unique heterogeneous porous structure in the composite aerogels. The aerogels achieve a minimum reflection loss of -59.4 dB at 7.6 GHz with a thin thickness of 2.31 mm, and the effective absorption bandwidth could be 4.24 GHz with an ultrathin thickness of 1.25 mm. The outstanding EWA performance can be attributed to the synergistic contribution of conductive loss, interfacial polarization loss, dipole polarization loss and magnetic loss. Moreover, the porous PI framework plays a crucial role in optimizing impedance matching and structural stability. The composite aerogels also demonstrate potential for radar stealth and thermal insulation. This work presents a new strategy for designing multifunction EWA materials.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Xinbin Ji,Yulong Xiang,Jing Guo,Fucheng Guan,Da Bao,Qiang Yang,Zheng Li,Yihang Zhang,Xin Zhang,Jiahao He
The integration of early warning and thermal protection functions in fire-prone environments remains a significant challenge in the development of intelligent protective textile materials. In this study, a structural regulation strategy is proposed, leveraging the synergistic templating and stress-orientation effects of carbon nanotubes (CNT) and Ag 2 Se nanorods to successfully construct a polyimide (PI)/pre-oxidized polyacrylonitrile (panof)/CNT/Ag 2 Se composite porous fiber (PPCAF) featuring a stable sheath–core architecture. The core, composed of a dense panof/CNT/Ag 2 Se (s) phase, offers thermal responsiveness and mechanical support. The shell comprises a porous PI matrix that buffers stress, insulates heat, and prevents Ag 2 Se degradation and shedding, thereby enhancing thermal conversion and signal stability. This rational architecture enables the fiber to rapidly respond to fire-induced thermal stimuli, achieving a maximum thermoelectric voltage of 4.5 mV within 1.8 s via the Seebeck effect, ensuring stable self-powered fire warning. Concurrently, the fiber exhibits excellent passive protection, including high tensile strength (18.93 MPa), flame retardancy (LOI: 55.6 %), low thermal conductivity (0.0298 W/m·K), and superhydrophobicity (contact angle: 160.2°). These integrated properties contribute to slowing flame spread, minimizing heat transfer, and blocking moisture intrusion. This study provides both theoretical insights and practical guidelines for designing advanced self-powered intelligent textile materials with dual fire protection functionalities.
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高影响因子
危险品化学品经营许可证（带存储）