ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Jiaojun Tan,Yanwei Luo,Meiyun Zhang,Bin Yang,Fangfang Li,Shaowei Ruan
Aramid paper has been widely used in high-voltage motors and transformers due to its excellent insulation property and thermal durability. However, the smoothness and chemical inertness of aramid fibers lead to a loose structure (voids) of aramid paper, which limits its potential applications in harsh environments, such as high-frequency and high-voltage circuits. This work reports a simple and efficient method to improve the mechanical and insulation properties of meta-aramid paper via controllable dissolving and regeneration of aramid fibers. To obtain a dense and robust structure, the pristine meta-aramid paper was immersed in a dimethyl sulfoxide/potassium hydroxide (DMSO/KOH) mixture to make aramid fibers swelled and dissolved, followed by regeneration in water vapor, eventually generating densified aramid paper with fewer voids and enhanced insulation and mechanical performance. Optimum conditions resulted in aramid paper with the best comprehensive performance, and the tensile strength, Young’s modulus, and electrical breakdown strength of the consolidated aramid paper were 22.85 MPa, 0.72 GPa, and 15.3 kV/mm, respectively, which were significantly higher than those of the pristine aramid paper (12.53 MPa, 0.41 GPa, and 8.36 kV/mm). Meanwhile, such treatment did not cause any chemical structure change, and thus it still retained the excellent thermal resistance (Td > 430 °C) of aramid fibers. This simple method can effectively regulate the surface porosity and the mechanical and breakdown strength of aramid paper, as well as provide a generic method for postprocessing and enhancing aramid paper.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 14
·12161-12168
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IF 2.324
Xie Fan,Qin Panliang,Zhuo Longhai,Lu Zhaoqing,Wang Yafang
The synthesis of ZnO nanowires (NWs) on aramid fiber (AF) surface via a facile in situ hydrothermal method was studied and the as-obtained AFs@ZnO NWs acting as the thermal conductive fiber fillers in the fabrication of aramid paper-based materials by wet-forming process were also investigated. SEM showed a dense and uniform ZnO NWs layer with vertical alignment was well established on surface of AFs. EDS and XRD characterization further confirmed the formation of ZnO NWs on AFs surface. Compared with the pristine paper, the composite paper exhibited better thermal conductivity increased by 129% from 0.0867 to 0.1985 W/m K and kept good insulating properties inherent to aramid paper. The excellent thermal conductivity of aramid paper was mainly attributed to the effective heat conduction networks formed by the AFs@ZnO NWs within the aramid paper. This study proposed an innovative way to fabricate fibrous thermally conductive filler, which effectively improved the dispersion, retention of fillers and interfacial bonding between fillers and fibers.
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
MATERIALS & DESIGN
·
2019
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IF 5.77
Ke Xu,Yanghao Ou,Yinghui Li,Lingfeng Su,Meiyan Lin,Yang Li,Jiedong Cui,Detao Liu
Aramid fibers exhibit impressive mechanical properties, electrical insulation properties, and chemical stability. However, physical properties of the aramid paper are poor because of the chemical inertness and smooth surface of aramid fibers. This study reports a simple and efficient method for substantially improving the performance of the para-aramid/meta-aramid composite paper by introducing the N , N -dimethylacetamide (DMAc)/LiCl solution to induce partial dissolution or by adding the DMAc/LiCl/para-aramid solution to induce regeneration. Experimental results state that the tensile strength, specific strength, folding resistance, and interlayer bonding strength of the aramid paper are increased by 2.17, 2.13, 34.7, and 9.39 times, respectively, because of the dense and compact structure of the paper. Furthermore, the water resistance of the paper was also considerably improved. After immersing the paper samples in water for 24 h, their moisture absorption rate decreased to approximately 54% from approximately 143% for the original paper. Results indicate that partial dissolution/regeneration welding is a viable method for the efficient reinforcement of the aramid composite paper, providing additional possibilities for manufacturing the high-performance aramid paper-based materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
High Voltage
·
2022
·Vol. 8
·期 4
·760-771
·
IF 4.967
Haoou Ruan,Qing Xie,Jingxuan Song,Shenghui Wang,Xiaobin Chang,Yuqin Xu,Fangcheng Lü
Organophilic groups of coupling agents can be the key factor for the electrical performance of Boron Nitride (BN)/meta-aramid composite paper. In this article, four types of triethoxy-silane coupling agents with different organophilic groups, including mercapto-propyl (MP), glycidylether-propyl (GP), amino-propyl (AP) and trideca-fluoro-octyl (TFO) were studied. The structural and electrical properties of modified papers were compared, and the molecular simulation was conducted to reveal the interface interaction of modified BN and aramid. The results show that AP, GP and MP follow the same mechanism, improving the electrical performance by modifying the interface stability and paper structure, and the ranks of improving effects are AP, MP and GP. While, TFO mainly relies on the fluorine components to implement the electrical reinforcement, which compensates for the shortcoming in the paper structure. By choosing TFO and filler content of 15 wt%, the optimal breakdown strength of the paper can be increased to 28.17 kV/mm, 1.8 times that of the paper doped with the hydroxylated BN.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Bin Yang,Haoran Wang,Meiyun Zhang,FengFeng Jia,Yuanqing Liu,Zhaoqing Lu
Undesirable electromagnetic interference (EMI) created by modern electronic devices has detrimental effects on the performance of high-precision electronic devices, information security, and human health. Therefore, lightweight, flexible, robust, and easy-to-fabricate EMI shielding materials with integrated functions are highly desirable to combat electromagnetic pollution. Herein, we report a scalable and facile strategy to prepare a flexible Ti 3 C 2 T x MXene-coated aramid paper (MAP) with high-efficiency EMI shielding and excellent electrical heating performance. The intertwined network by aramid fibers endows the aramid paper (AP) with superior mechanical properties. After selectively single/dual coating with MXene onto AP, the MAP maintains a superior tensile strength of 73.6 MPa and enormous folding endurance of 4156 times. Owing to the exceptional electrical conductivity of MXene, the MAP with a relatively low MXene content (∼9.0 wt%) exhibits excellent overall performance with an EMI shielding effectiveness (SE) of 38 dB and SE/t of 422.2 dB mm −1 . It’s noteworthy that the EMI SE of the MAP remains almost unchanged (37.4 dB) even after experiencing 5,000 repeated bending cycles. Additionally, the MAP shows satisfactory Joule electric-heating capability (a heating temperature rise of 130 °C at a low driving voltage of 5 V) and excellent flame-retardancy. This work provides a feasible strategy for large-scale production of flexible EMI shielding paper with multifunctional properties for future wearable facilities.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2024
·
IF 8.3
Fangcheng Lv,Lvqian Fu,Qibin Wang,Kaixuan Sun,Rui Yang,Sidi Fan,Xiang Yu
High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains , exposing carbon residues resulting from electrical breakdown . These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds . This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90 % of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency.
研究领域:
材料科学
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环境工程
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Ping Xie,Na Li,Kairong Zhao,Yutong Cao,Junrong Yu,Yan Wang,Zuming Hu
At present, the mechanical properties of para aramid paper (PPTA paper) are still severely challenged since interface bonding defects. In this work, a novel method for improving the interface bonding of PPTA paper was proposed by introducing m-phenylenediamine (MPD) into PPTA molecular chain by copolymerization. Result showed that the addition of MPD could monitor the rigidity and glass transition temperature (Tg) of PPTA. The Tg generated by the copolymerized modified PPTA precipitated fibers (MAPFs) realized micro-melting bonding with adjacent fibers during hot-pressing process. Further optimization of MAPFs precipitation and hot-pressing process improved the tensile strength of paper. Results indicated that the tensile strength of paper made of MAPFs with 60% MPD far beyond PPTA paper (PAP), and was 1.07 times of Nomex paper. The method provides a reference value for the application of high performance PAP in lightweight and high strength fields, broadening the application field of PAP as well.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 23
·1880
·
IF 4.4
Xiaonan Li,Tong Qin,Wenxu Zhang,Hong Wang,Yanhong Chen,Kangle Li,Qing Wang,Yibo Wang
When the power converter connects to the high-frequency transformer breaks through the bottleneck and reaches a frequency of 100 kHz or even higher, the high-frequency transformer’s inter-turn insulation faces more serious high-frequency discharge and high-temperature problems. In order to improve the service performance of oil-immersed high-frequency transformer insulation paper, composite K-BNNS particles are prepared by ultrasonic stripping, heat treatment, and thermomagnetic stirring. Then, K-BNNS particles are mixed with PMIA (polymeric m-phenylenediamine solution) slurry to produce composite aramid paper. And the effects of K-BNNS particles with different contents on the thermal conductivity, dielectric properties, partial discharge properties, and mechanical properties of aramid paper are explored. It can be found that, when the addition of composite particles (K-BNNS) is 10%, the comprehensive performance of composite aramid paper is the best. Compared with Nomex paper, the in-plane and through-plane thermal conductivity of composite insulating paper F-10 increased by 668.33% and 760.66%, respectively. Moreover, the high-frequency breakdown voltage increased by 48.73% and the tensile strength increased by 2.49%. The main reason is that the composite particles form a complete thermal conductive network in the aramid paper matrix and a large number of hydrogen bonds with the matrix, which enhances the internal interface bonding force of the material and changes the charge transport mechanism.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS D-APPLIED PHYSICS
·
2025
·Vol. 58
·期 14
·145502
·
IF 3.2
Yuxuan Gao,Xinghan Du,Qibin Wang,Yaping Cui,Wenqi Zhang,Sidi Fan,Xiang Yu
The durability of superhydrophobic coatings has emerged as a pivotal consideration for their practical applications. Conventional methods for preparing robust superhydrophobic coatings often incorporate chemical binders. However, these binders are susceptible to melting and embrittlement under high temperatures, greatly limiting their stable service life, particularly in complex outdoor environments. Herein, the meta-aramid papers are treated with superhydrophobic modification using the surface-embedded spray coating technique. Benefiting from the unique deprotonation and reprotonation features of meta-aramid fibers, the paper surface morphology is reconstructed into a porous micro–nano structure. Given the comparable dimensions between the hydrophobic nano-SiO2 particles and the surface pores, the SiO2 particles become surface-embedded within the pores, resulting in a firmly bonded superhydrophobic coating. Furthermore, additional hydrogen bonds are formed between the SiO2 particles and meta-aramid fibers, further strengthening their adhesion. The as-prepared paper can endure temperatures up to 260 °C, preserving a contact angle >150° and a sliding angle <5°. It also exhibits exceptional abrasion durability even after thermal aging. Additionally, the DC wet flashover voltage maintains over 95% of its original value. Our surface-embedded strategy offers an innovative alternative to chemical binders and enhances the viability of superhydrophobic coatings for applications in high-temperature environments.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
·
2024
·Vol. 31
·期 4
·1815-1822
·
IF 2.9
Hao-ou Ruan,Shi-xun Hu,Jing-xuan Song,Xiong Liu
This study investigates the impact of interface defects on the electrical performance of epoxy-impregnated aramid papers (EAPs). Various composites with different degrees of defects were prepared and analyzed for their structural, mechanical, partial discharge, and insulation performance. The results demonstrate the widespread presence of void defects in the composites, negatively affecting paper compactness, mechanical properties, initial discharge voltage, and leading to significant gas gap discharge phenomena. In terms of insulation performance, composites with severe defects exhibit a 40-fold increase in low-frequency dielectric loss, a 16-fold increase in electrical conductivity, and up to a 64% reduction in breakdown field strength, along with noticeable shallowing of charge traps. Phase field modeling of electro-thermal breakdown reveals that void-type defects guide discharge trajectories, causing lateral damage diffusion, localized overheating, and severe electric field distortion, ultimately endangering the voltage resistance. This study provides the research support for the application of aramid paper as a matrix for a novel epoxy-impregnated insulating paper.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Fengdong Teng,Na Li,Ying Yuan,Yutong Cao,Junrong Yu,Yan Wang,Zuming Hu
Poor interfacial bond strength and complex processing limit the widely use of para-aramid paper. Here, the meta-poly(p-phenylene terephthalamide) (MPPTA) was obtained by introducing poly(m-phenylene isophthalamide) (PMIA) segments into the PPTA rigid molecular chains via secondary polymerization. The rigid-soft molecular structure not only gives MPPTA excellent thermal stability, but also enables the MPPTA fibrids to bond to the PPTA chopped fibers by plastic deformation during hot pressing. The tensile strength of Precipitated-MPPTA-paper (P-MPPTA-p) was increased by 20.3 % compared to Precipitated-PMIA-paper (P-PMIA-p). And the interfacial bond strength of aramid paper can be further improved by combining MPPTA solution and PPTA nonwoven fabric through a simpler and more efficient solution casting method, which together with more moderate hot pressing conditions can lead to the tensile strength of aramid paper up to 109.1 MPa, as well as exhibiting higher resistance to tearing and heat aging. The present study provides a new idea for the efficient preparation of para-aramid paper with excellent comprehensive performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 8
·3687-3700
·
IF 4.5
Gu Siqi,Xie Ping,Hu Zuming,Yu Junrong,Wang Yan,Li Na
Because of excellent insulation properties and thermal stability, meta-aramid paper can be commonly applied to a vast number of fields, like power systems. But poriferous and relatively lax structure of meta-aramid paper would limit its applications in high-voltage environment. This paper proposes a sandwich structure design to combine PDA@BNNS/PMIA film and meta-aramid paper with high breakdown strength. After coating with 6 wt% PDA@BNNS/PMIA solution, this kind of paper became more compact, so there were few pores in the paper and it further enhanced the mechanical and dielectric performances of specimens. The tensile strength in the cross direction increased from 31.3 to 40.5 MPa, and the performance in the machine direction was from 75.5 to 78.9 MPa. Furthermore, the breakdown strength of compound-coated paper achieved 55 kV/mm, which is much higher than meta-aramid paper. Additionally, compound-coated paper still remained outstanding thermal stability. Overall, our fabricated PDA@BNNS/PMIA compound-coated paper has excellent comprehensive properties, which provides a broad prospect for the applications in high-temperature and high-voltage transformers.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）