COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Xiaoyuan Zhang,Yuqi Yang,Gui Yang,Fengmei Su,Youxin Ji,Chuntai Liu
Durable and multifunctional electromagnetic interference (EMI) shielding materials have garnered significant attention due to their growing application demands. However, achieving optimal EMI shielding performance remains challenging, primarily due to the inherent interfacial resistance among conductive fillers. In this study, a novel polyimide@silver-sintered (PI@Ag–S) nanofiber composite was developed through in situ anchoring and low-temperature sintering of Ag nanoparticles (AgNPs) on electrospun PI nanofibers. The sintering process created a highly interconnected AgNPs layer, significantly reducing the electrical resistance and enhancing the electrical conductivity from 49 S/cm to an exceptional 154 S/cm. The resulting PI@Ag–S nanofiber composite demonstrated outstanding EMI shielding effectiveness (86.7 dB), and a remarkable SSE/t value of 14985 dB cm 2 g −1 , alongside excellent in-plane thermal conductivity (2.6011 W/(m⋅K)). Additionally, the composite showcased superior electrical heating performance, enabling effective defogging and de-icing operations at a low voltage of 1.5 V. Notably, the composite, protected by an ultrathin 8 μm PI coating, exhibited exceptional durability, including resistance to extreme temperatures, strong acid and alkali corrosion, and flame-retardant properties. These attributes make the flexible PI@Ag–S nanofiber composite a promising candidate for advanced EMI shielding and thermal management applications, particularly in harsh environments.
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DOI
高影响因子
Journal of Building Engineering
·
2025
·
IF 7.4
Chao He,Anze Shui,Jiayi lou,Liuhai Ni,Hulei Yu,Sai Xu
The effective utilization of sound-absorbing materials is the primary approach to treat noise pollution, which represents a principal public health and environmental issue. However, current research on acoustic absorption materials has several drawbacks, including narrow sound absorption frequency bands, low sound absorption coefficients, and excessive material thickness. Herein, we propose a facile sound-enhanced strategy that integrates a micro-sized polyimide (PI) membrane network and nanoscale FeBTC metal-organic frameworks into a submillimeter porous ceramic with high open porosity and multiscale pore structure. The enhancement of broadband sound absorption performance can be achieved by adjusting the freeze-casting temperature and precursor solution concentration to regulate the distribution density of the PI membrane network. Furthermore, the med-low frequency acoustic performance was further enhanced by in-situ growth of FeBTC within the fabricated organic-inorganic composites featuring a dual network structure. Across a broadband frequency range of 500 Hz to 6300 Hz, the composites exhibited an average sound absorption coefficient (SAC) of 0.64 and an average sound transmission loss (STL) of 20.5 dB at a thickness of 15 mm, which was significantly higher than that of commonly available noise reduction products and advanced sound absorbers ever achieved. The synergistic sound absorption effects of the hierarchical structure play a significant role in achieving a remarkable noise reduction ability. Moreover, the low thermal conductivity and excellent environmental stability of this composite material make it suitable for a wide range of applications requiring broadband noise control, including building design, transportation, and precision instruments.
研究领域:
材料科学
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声学功能材料
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复合材料工程
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环境噪声控制
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纳米材料应用
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qicheng Xue,Nanxi Dong,Peiqi Fan,Daolei Lin,Guofeng Tian,Jun Liu,Jiaming Wei,Shengli Qi,Dezhen Wu
The extreme temperatures encountered in aerospace pose formidable challenges to the performance of elastic materials in spacecraft and related apparatus. Traditional organic insulation materials face hindrance due to inadequate fire resistance, while inorganic insulation materials are often brittle. Herein, we designed binary-network composite aerogels with dual-crosslinked PI nanofibers as the scaffold and uniformly distributed silica nanoparticles within the anisotropic aerogel matrix. Owing to the dual-crosslinked PI nanofiber network, the resulting PI@SiO 2 aerogel can withstand 1000 cycles of radial fatigue testing under 50 % compressive or buckling strains, maintaining structural stability across a wide angular frequency range of 0.1–100 rad/s. DMA testing shows that PI@SiO 2 aerogel can endure 100,000 fatigue cycles from 25 to 300 °C, with storage modulus and loss modulus, and damping ratio, indicating robust long-term performance over a wide temperature spectrum. Even with liquid nitrogen (−196 °C) and butane torch flames (1100 °C), PI@SiO 2 aerogel preserves its superelasticity through repeated compressions. Moreover, the composite aerogel exhibits excellent thermal insulation , with low thermal conductivity (27.2 mW m −1 K −1 ), and reachs the top flame-retardant level (UL94-V0). This work not only establishes a novel pathway for constructing polymer-based materials with temperature-invariant superelasticity but also holds great promise for extensive applications in ongoing and near-future aerospace exploration.
研究领域:
材料科学
·
航空航天工程
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DOI
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 9
·1806
·
IF 4.324
Dawei Li,Huizhong Liu,Ying Shen,Huiping Wu,Feng Liu,Lanlan Wang,Qingsheng Liu,Bingyao Deng
Electrospun nanofiber, showing large specific area and high porosity, has attracted much attention across various fields, especially in the field of air filtration. The small diameter contributes to the construction of filters with high-filtration efficiency for fine particulate matter (PM), however, along with an increase in air resistance. Herein, composited nanofiber aerogels (NAs), a truly three-dimensional (3D) derivative of the densely compacted electrospun mat, were constructed with the blocks of polytetrafluoroethylene–polyamideimide (PTFE–PAI) composite nanofiber and polyimide (PI) nanofiber. PI/PTFE–PAI NAs with hierarchically porous architecture and excellent mechanical properties have been obtained by thermally induced crosslink bonding. Results indicated that sintering at 400 °C for 30 min could complete the decomposition of polyethylene (PEO) and imidization of polyamic acid (PAA) into PI, as well as generate sufficient mechanical bonding between adjacent nanofibers in the NAs without extra additive. The well-prepared PI/PTFE–PAI NAs could withstand high temperature up to 500 °C. In addition, the filtration tests illustrated that the composite NAs had an excellent performance in PM filtration. More importantly, the filtration behavior could be adjusted to meet the requirements of various applications. The excellent thermal stability and high-filtration efficiency indicated its great potential in the field of high-temperature air filtration.Keywords:nanofiber-based aerogels;PTFE–PAI nanofiber;high-efficiency filter;PM2.5;hierarchical porous architecture
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2023
·Vol. 44
·期 5
·2757-2765
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IF 5.2
Linyu Pu,Yu Li,Jingyuan Tang,Yiting Long,Wei Wang,Yatang Dai,Xu Huang
Firstly, the BaTiO 3 nanoparticles were coated with a layer of paraffin, forming a core shell structure. Then, as-prepared paraffin@BaTiO 3 nanofillers were directly blended with polyimide (PI) prepolymer to fabricate paraffin@BaTiO 3 /PI composite films. The microstructure, thermal, and dielectric properties were investigated in detail. The surface-modified paraffin@BaTiO 3 nanoparticles exhibited a typical core shell structure with uniform and complete coverage. The char yield of the composite film with 10 wt% paraffin@BaTiO 3 increased from 56.40% to 70.73%. It is obvious that the paraffin@BaTiO 3 nanofillers have a positive effect on ablative performance of the composite film. Compared with pure PI, the ε r of paraffin@BaTiO 3 /PI composites with 40% mass fraction increased from 3.41 to 9.35 (1 kHz). The tanδ of paraffin@BaTiO 3 /PI composites was just 0.0065 (1 kHz) when the filler loading was 40 wt%. Temperature dependency of the permittivity of the composites reveals a zero-temperature-coefficient from 80°C to 180°C.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 17
·3605
·
IF 4.967
Jiang Wu,Bo Zhang,Tianjiao Li,Yan Du,Wen Cao,Hao Yang
The operating safety of spacecraft in space environments is closely related to the surface discharging phenomenon of dielectrics such as polyimide (PI) film in solar arrays; moreover, carrier traps in the dielectric can affect its insulation performance. Therefore, to improve the vacuum surface flashover characteristics of PI film by nano modification and reveal the effect of trap distribution on the flashover of PI composite film, first, the original PI and nano-ZnO/PI composite films with different additive amounts (0.5, 1, 2, and 3 wt.%) were prepared by in situ polymerization and their performance was evaluated by the physicochemical properties characterized by methods such as thermogravimetric analysis; second, the surface traps of the original and nanocomposite films were measured and calculated by surface potential decay method, and the carrier mobility was also obtained; finally, the vacuum direct current (DC) surface flashover characteristics and bulk resistivity of all the film samples were measured and analyzed. The experiment results showed that with the increase in the amount of nano-ZnO, both the shallow and deep trap density increased significantly, while the trap energy varied slightly, and the surface flashover voltage also increased obviously. Based on the multi-core model, the increases in the shallow and deep trap density after the introduction of nano-ZnO into the PI matrix was analyzed from the microscopic perspective of the interface. Based on the comparative analysis of the trap distribution and surface flashover voltage characteristics, a bilayer model of vacuum DC surface flashover development was proposed. In the bilayer model, deep traps and shallow traps play a dominant role in the vacuum–solid interface and the inner surface of the dielectric, respectively, and increasing the trap density could effectively inhibit secondary electron multiplication on the surface and accelerate charge dissipation inside the film. Consequently, nano-ZnO can purposefully control the trap distribution, and then improve the flashover characteristics of nano-ZnO/PI composite films, which provides a new approach for improving the spacecraft material safety.Keywords:nanocomposite;polyimide film;trap distribution;DC surface flashover;bilayer model
研究领域:
材料科学
·
航天工程
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产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Chengyi Si,Yawen Zhang,Le Li,Tian Zhang,Hongyu Liu,Ao Men,Xiaoqiang Fan,Minhao Zhu
Despite methylphenylsiloxane (MPS) possesses heat-resistance and corrosion resistance , the brittleness hinders its widespread application. Herein, the polyimide (PI) and Ti 3 AlC 2 were introduced for modifying MPS, thereby preparing the T-PI-MPS coating. The bilayer structure of surface-enriched MPS and internal-enriched PI was achieved by controlling the addition amount along with the density difference. The results indicate that the T-PI-MPS coating achieved a contact angle of 95.1° and exhibited corrosion resistance to salt spray for 28 days. Compared to PI-MPS, the wear rate of T-PI-MPS was reduced by 85 % and the friction coefficient declined from 0.75 to 0.58. As expected, T-PI-MPS exhibited exceptional excellent heat-resistance. The exceptional performance is attributed to the following three factors: I. the MPS-enriched layer is characterized by a stable Si O chain organization. This structure gives the corrosion resistance and water resistance, and prevents the hydrolytic swelling of PI. II. the PI-enriched layer is constructed from imide bonds, which give the coating superior friction performance due to its high load-bearing capacity. III. the incorporation of Ti 3 AlC 2 plays a role in mitigating internal defects, prolonging the corrosion path, and inhibiting cracks due to its unique nanolayered structure, high temperature resistance, and hardness.
研究领域:
材料科学
·
腐蚀与防护
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表面工程
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DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2023
·
IF 6.2
Chengyi Si,Meng Cai,Guojuan Liu,Yawen Zhang,Xiaoqiang Fan,Minhao Zhu
Despite polyimide (PI) has been regarded as heat-resistant aviation material, but its high friction coefficient and insufficient abrasion resistance hinder the wide application. Herein, a versatile PDMS-PI composite coating with double-layer structure was prepared by crosslinking hybrid. The effect of polydimethylsiloxane (PDMS) on the hydrophobic, heat-resistant and tribological properties of PDMS-PI composite coating was explored. As expected, compared with the PI and SiO 2 -PI, PDMS-PI coating achieved the contact angle of 108.5° and only 5 wt% heat loss temperature at 578 ℃. Additionally, its wear rate obviously decreased by 38.5 %, and the friction coefficient declined from 0.33 to 0.07. The improvement contributes to excellent hydrophobic and heat resistance of dense protective layer and low-friction/wear of the PDMS coating layer .
研究领域:
材料科学
·
表面工程
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DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2025
·
IF 6.9
Zihui Yu,Yan Wang,Qihua Wang,Yaoming Zhang,Zhancheng Zhang,Meizhe Yu,Xianqiang Pei
Carbon fibers were functionalized by metal-organic frameworks (MOFs), referred to as MCFs, through chemical self-polymerization and solvothermal reactions, and then combined with polytetrafluoroethylene (PTFE) to construct a hard-soft cross-scale synergistic structure, resulting in the preparation of polyimide (PI) composite coatings. Tribological tests were conducted under different conditions, after which the fundamental role of MCFs and PTFE in modifying the friction-reduction and anti-wear performance of PI was discussed based on in-depth characterization of the composite coatings' worn surface and transfer films formed on the counter steel surface. It was revealed that the MCFs/15PT/PI composite coating exhibited excellent tribological properties, which also exhibited high friction stability and wear resistance across varying loads and sliding speeds. Additionally, the composite coating was found to be potentially applicable for maintenance-free applications due to its excellent long-term tribological performance.
研究领域:
材料科学
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摩擦学
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聚合物复合材料
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表面工程
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产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2025
·
IF 2.7
Zhicheng Wu,Xiang Li,Zhiyong Lv,Bo Liu,Siyang Chen,Qiaogen Zhang
Real-time and accurate detection of moisture content in insulating oil is crucial for the safe operation of oil-filled electrical equipment. This study presents a method for preparing hydrophobic porous PI films for moisture sensing using supercritical CO 2 foaming (SCF) technology. The resulting porous PI films have a uniform and dense nanometer-scale microporous structure, with a water contact angle of 111.7°, indicating strong hydrophobicity and enabling the mitigation of hysteresis-induced measurement inaccuracies. Compared to sensors made using traditional methods such as non-solvent induced phase separation (NIPS), the moisture sensors fabricated using this method exhibit a response time of 10 s, with humidity hysteresis reduced from 9.1 %RH to 2.3 %RH, achieving both fast response and low humidity hysteresis. This method also holds broad application prospects in areas such as permeation membranes and energy.
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DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Peng Wei,Dong Huang,Chen Luo,Yang Sui,Xi Li,Qingkun Liu,Bensheng Zhu,Chuanbo Cong,Qiong Zhou,Xiaoyu Meng
Due to its uncomplicated manufacturing procedure for large-scale industrialization and adaptable conductivity, the competitive proton exchange membrane (PEM) matrix employed is sulfonated poly (ether ether ketone). However, the conflict between the strong proton conductivity and high stability of SPEEK-based PEM constantly upsets the equilibrium; the primary chain of SPEEK will conduct more protons if additional sulfonic acid is introduced, but it also causes a high swelling ratio and lowers stability. To tackle this challenging issue, we coupled the high intrinsic proton conductivity of phosphotungstic acid (HPW) and the excellent stability of polyimide (PI) nanofibers in a single PEM. In particular, sandwich-structure hybrid membranes (PI/SPEEK + HPW) were created to reduce HPW loss under operational conditions, further improving stability. Consequently, the swelling ratio and conductivity of the premium sandwich-structure PI/SPEEK + HPW-20 were 29% and 223.4 mS cm −1 under 60 °C and 100% RH, their respective values were 8% larger than those of SPEEK. Its proton conductivity reached 170.9 mS cm −1 during 13 days of exposure under 60 °C and 100% RH, which would be 30% better than that of SPEEK over the same treatment. Protons in these membranes were transported through Grotthus and vehicle mechanism, and the establishment of an acid-rich layer at the surface among PI nanofiber with HPW/SPEEK, which was confirmed by FTIR, XPS , and TEM , is responsible for these superior performances. From our point of view, our findings might encourage more studies into the creation of high-performance PEM.
研究领域:
材料科学
·
高分子化学
·
能源材料
·
电化学
·
膜科学与技术
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DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2019
·
IF 3.42
Wentao Li,Wenjie Zhao,Lisha Mao,Shengguo Zhou,Chao Liu,Zhiwen Fang,Xiulei Gao
In this work, fluorinated graphene (FG) nanosheets with different F/C fluorination degree were synthesized by a convenient gas phase fluorination method. Ionic liquids was used to modify the FG to improve its dispersion and compatibility in polyimide (PI). The thermal, mechanical and tribological properties of FG/PI composite coatings were investigated systematically. The morphology of FG was observed by Transmission electron microscopy (TEM) and scanning probe microscope (SPM). The physical and chemical properties of the FG were characterized by a large number of measurement methods, such as X-ray powder diffraction (XRD), Raman spectra, X-ray photo-electronic spectroscopy (XPS) and so on. Fourier transformed infrared spectra (FTIR) was used to confirm the successful modification of ILs. And the Chemical composition of the PI coating was investigated by XPS and FTIR measurements. On the basis of the stable dispersion of FG in the PI matrix, compared with pure PI, the composite coating with (reduced graphene oxide) rGO owned slightly improved thermal, mechanical and tribological properties and the composite coating with FG displayed significant improvement, especially when the F-doped degree was the highest.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）