Journal of Materials Chemistry C
·
2024
·
IF 5.7
Liangkang Huang,Jianwei Li,Shuting Chen,Bilin Zhang,Shengping Li,Wei Fan,Qiangli Zhao,Xuman Wang
Developing a piezoelectric polymer with high-temperature resistance is crucial for fabricating flexible piezoelectric sensors that can be used under extreme conditions. Herein, we for the first time found the piezoelectric properties of polyimide (PI) nanofibers and further enhanced their output voltage characteristics by introducing a fluorine-containing hexafluorodianhydride (6FDA) unit into the PI nanofibrous matrix. The as-fabricated sensor can produce a stable piezoelectric output of 10 V with a 478.72 mV N−1 sensitivity. The response and recovery times are 15 ms, respectively, and the output can remain stable after 10,000 cycles at 15 Hz/10 N, demonstrating excellent durability. Meanwhile, the 10–30 V piezoelectric output signals generated by different actions can be accurately identified for wearable applications. Furthermore, it is found that fluorinated polyimide (FPI) prepared by electrospinning can maintain structural stability before 500 °C, and its thermal decomposition temperature is above 550 °C. Moreover, the surface morphology with high porosity and the low surface energy of F atoms endow the nanofiber film with excellent superhydrophobic properties with a water contact angle of 139.6°. This work presents PI nanofibers with high-temperature resistance and outstanding piezoelectric properties, laying a potential foundation for their application in wearable and flexible electronic devices that can be used in extreme environments.
研究领域:
材料科学
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传感器技术
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Xiaojuan Feng,Hongyan Wang,Lingxiao Yan,Chaonan He,Yu Chen,Song Xue,Qiang Liu
High-performance polymeric separators are indispensable materials for advanced rechargeable lithium-ion batteries (LIBs). In general, separators must simultaneously possess the following qualifications: flame retardancy, mechanical strength, wettability, and ion conductivity. In this paper, a siloxanediamine, namely, 1,3-bis(aminopropyl)tetramethyldisiloxane (APTMDS), is introduced as a means of improving the mechanical properties of the pristine polyimide (PI) separator through hydrolysis-cross-linking. Moreover, dopamine (DA) undergoes self-polymerization to form polydopamine (PDA), which adheres to the surface of the composite separator. This process enhances the compatibility of the separator with the electrolyte. The three-layer composite separator of PI/APTMDS/PDA displays superior wettability, fire resistance, and conductivity in comparison to those of a Celgard-2400 separator. In particular, PI/APTMDS/PDA separators display superior battery capability (128.17 mAh·g–1@5 C, LiFePO4IILi) in comparison to polypropylene separators (115.4 mAh·g–1@5 C, LiFePO4IILi). Moreover, the cell employing the PI/APTMDS/PDA separator displays high cycling stability and discharge specific capacity over 100 cycles at 1 and 9 C. The present study offers an excellent design concept for the preparation of modified separators for LIBs.
研究领域:
材料科学
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能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Haiyan Guo,Lingbin Liu,Yuxiu Yu,Qiang Zhang,Qing Chang,Yaodong Liu
Binders play a vital role in silicon-based anode materials. In this study, we design and synthesize a series of silicon-based anode binders by incorporating functional monomers such as Diaminobenzoic acid (DABA), Aminopropyl terminated polydimethylsiloxane (PDMS) and 4,4′-diphenyl ether dianhydride (ODPA) into polyimide (PI) backbones. The goal is to develop binders with a balance of rigidity and flexibility to improve the electrochemical performance of silicon anodes in lithium-ion batteries. It is found that the chemical structure of the binder affects the swelling rate, bond strength and rigidity, which thereby impacts the electrochemical performances of silicon anode. The incorporation of (PDMS) enhances the binder's flexibility, which effectively accommodates the volume expansion of silicon during cycling, thereby improving cycling stability. However, excessive PDMS content leads to increased swelling rates and weakened adhesion, negatively affecting the formation and stability of the solid electrolyte interphase (SEI) layer and reducing first Coulombic efficiency (ICE). The co-polymerization of 1,3-bis(aminopropyl) tetramethyldisiloxane (NH 2 -DS) reduces the binder's solubility, resulting in improved ICE. Among the binders tested, Si@ODPA-NH 2 -DS-DABA exhibits the best cycling performance, has a specific capacity of 1690.2 mAh g −1 after 200 cycles at 0.2 C, due to its optimal rigid-flexible ratio, lower swelling rate, and stronger adhesion to the electrode. The synergistic effect of rigid benzene rings, imide bonds, and flexible ether and Si-O-Si units provide high strength, toughness, and adhesion. This study provides valuable insights into the design of silicon anode binders, demonstrating that a careful balance of binder flexibility, swelling rate, and adhesive strength is essential for achieving superior electrochemical performance and long-term cycling stability.
研究领域:
材料科学
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电化学
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电池技术
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2024
·
IF 8.1
Fan Wang,Xiaodi Dong,Guangyi Liu,Baoquan Wan,Jinghui Gao,Baixin Liu,Jun-Wei Zha
Polyimide (PI) is widely used in electronic, electrical and communication fields because of its outstanding mechanical properties, electrical insulation and thermal stability. However, the lower thermal conductivity limits their application. Here, PI composite films with high thermal conductivity are obtained by utilizing reactive groups on the carbon nitride nanosheets (CNNS) surface to form covalent bond with PI matrix. The thermal conductivity of CNNS/PI composite films can reach 5.84 W∙m −1 ∙K −1 , which is about 10 times higher than that of pure PI (0.56 W∙m −1 ∙K −1 ). This is attributed to the covalent bond between CNNS and PI matrix acting as a “thermal bridge” to connect the discontinuities at the interface, thereby reducing the interfacial thermal resistance between CNNS and PI. The heat transfer mechanism of composite film is further revealed by finite element analysis . This work provides a viable solution to improve the thermal conductivity of PI, allowing for a wide range of potential applications for PI in electronic devices.
研究领域:
材料科学
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热物理学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Jialin Zhang,Jie Dong,Xin Zhao,Xiuting Li,Qingsong Xu,Qinghua Zhang
With the trend toward lighter and longer-lasting spacecraft operating in harsh environments, developing advanced high-performance polymer materials with adequate photostability has become an urgent issue. Here, a strategy is proposed to introduce UV-absorbing units as pendent side groups into polyimide (PI) backbone to develop intrinsic PI materials through molecular structure design. Compared with direct incorporation into polymer backbone, this method has a minimal impact on diamine reactivity, enabling the preparation of PI with high molecular weights, and more effectively inhibiting initial UV degradation. The addition of only 5 % of functional monomers for copolymerization can significantly enhance UV resistance while maintaining excellent mechanical and thermal properties. Furthermore, for PI fibers, combining chemical structure with the regulation of the aggregate structure during fiber spinning and heat-drawing process can produce high-performance PI fibers with superior overall properties. Unlike the conventional addition of inorganic nanoparticles or organic UV absorbers, this work aims to establish the relationship between chemical structure, material properties, and UV degradation mechanism. It provides a novel approach from the perspective of molecular structure design for advanced high-performance polymers that require complex processing and stringent performance demands, including long-term UV resistance and mechanical performance.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 32
·e55759
·
IF 2.7
Sizhao Zhang,Chun Liu,Zhao Wang,Jing Wang,Guangyu Xu,Hongwei Shi
Polyimide (PI) aerogels possess a rather potential in thermal protection material for aircraft, owing to their low thermal conductivity, high thermal stability, and low bulk density. However, the large shrinkage of pure PI aerogels is still a challenge in the complete preparation process. Herein, a kind of PI hybrid aerogel composite was prepared successfully by introducing polyurethane fiber as the reinforcing agent. The aerogel composite could realize the enhancement for the pure PI aerogels from a micro/macroscopic perspective, ultimately ensuring the ultralow shrinkage rate of 3.52%. Due to the inhibition of the shrinkage characteristic, the aerogel composite obtained achieved excellent thermal insulation, especially retaining a low temperature of 40.7°C despite the hot surface temperature reached up to 150°C. Besides, the lightweight low-density, exceptional flame resistance, and self-extinguishing properties were reflected from PI hybrid aerogel composite constructed, including the outstanding hydrophobic feature (water contact angle of 120°). The PI hybrid aerogel composite as prepared may be used for the thermal management of aircraft in a great measure, illustrating the feasible strategy of fabricating PI-based aerogel composites.
研究领域:
材料科学
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航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xiaolei Wang,Kunlong Zhao,Wenxin Cao,Dongchao Ji,Zhijie Ye,Zhenhua Su,Ge Gao,Zhuochao Wang,Chunqiang Sun,Yingqi Liu,Lan Zhang,Tianyu Zhang,Feiran Li,Jiaqi Zhu
High-performance aerogels are highly desirable in the fields of thermal barriers, drug delivery, and mechanical cushions; however, most of the reported aerogels are limited by complex preparation processes and single functionality. To address such issues, in this study, we prepare a series of aramid nanofiber (ANF)/polyimide (PI) multifunctional composite organic aerogels via a facile polyimide-coating-on-aramid nanofiber (PCoA) strategy. This strategy utilizes PI to coat on the surface of ANFs and construct numerous mesopores within the ANF three-dimensional network skeleton to make the ANF/PI composite aerogels exhibit superior multifunctional properties, such as outstanding thermal and acoustic insulation, mechanical strength, thermal stability, flame retardancy, and hydrophobicity. In particular, the as-prepared composite aerogels with a PI content of 20 wt% exhibit a thermal conductivity of 23.20 mW/mK, which is lower than that of air, and their specific Young’s modulus reaches 32.57 MPa/(g/cm 3 ), the highest among all previously reported organic aerogels, at a density of only 14.86 mg/cm 3 . The composite aerogels are destined to be extremely valuable as they can combine so many remarkable properties in a single package. Currently, the composite aerogels have been available in the form of ultrathin thermal insulation films at a thickness of only 100 μm, which can provide effective heat protection in microelectronic devices, and remain a terrific ability to operate under extreme conditions. Owing to these superior multifunctional properties, the ANF/PI composite aerogels show enormous potential for application in numerous fields, such as thermal management, environmental governance, catalysis, and energy storage.
研究领域:
材料科学
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化学工程
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Siyao Wang,Jingfa Zhang,Yongchao Sun,Fangxu Fan,Qizheng Zhao,Gaohong He,Canghai Ma
Thermally rearranged (TR) polymers are increasingly pivotal in gas separation membranes, with a pressing need for advancements in mechanical strength and separation performance. In this work, a novel variety of TR polymers were synthesized by polymerizing an amine-functionalized triptycene structure with thermally rearrangeable ortho -hydroxy groups. The TR membranes demonstrate enhanced gas permeability in H 2 /CH 4 and CO 2 /CH 4 tests and increased polymer chain spacing. Additionally, incorporating triptycene enhanced the mechanical properties of TR polymers, primarily attributed to the π-π stacking interactions of the triptycene units. Notably, the 6FDA-BAP:DAT (2:1) membrane thermally rearranged at 400 °C exhibited a H 2 permeability of 225.3 Barrer and a H 2 /CH 4 selectivity of 146.3, representing increases of 320 % and 154 %, respectively, compared to the precursor, and surpassing the H 2 /CH 4 upper bound. This work presents a robust design strategy for preparing mechanically durable TR membranes with enhanced gas separation 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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Weilin Feng,Lu Xu,Yuji Chen,Jiaqi Li,Hukang Guo,Mengxiao Zhang,Xiaohe Wang,Jianyu Wang,Chuanjie Fang,Liping Zhu
Integrally-skinned asymmetric (ISA) polymer membranes show enormous potential in efficiently energy-saving organic solvent nanofiltration (OSN) due to their excellent structural stability. However, the control of their microstructures at the nanoscale is technically challenging, making it difficult to simultaneously achieve high separation resolution and high solvent permeance. In this work, we report the in-situ evolution of polyimide ISA membranes from ultrafiltration to nanofiltration through thermal-induced densification of the surfaces. This process was attributed to the surface dynamics of polymers — i.e., the polymer segments on surface are more freely movable than that in bulk. The optimum treatment temperature was located between the glass transition temperatures of surface and bulk, which were measured based on porosity changes. The as-prepared ISA membranes with thin and dense skin layers exhibited high solvent permeance (e.g., over 5 L m −2 h −1 bar −1 for ethanol) and favorable molecular weight cut-off of around 300 Da. The membranes rivaled the state-of-the-art thin film composite membranes, demonstrating great potential in fast and precise molecular separation in OSN.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2024
·
IF 2.7
Xiaohua Li,Kunfeng Li,Huilong Shao,Shuang Zhao,Guobing Chen,Zhen Zhang,Zhicong Gan,Yilong Song,Zichun Yang
The freeze-casting is widely utilized as a tool for regulating micro-scale pore structures in the fabrication of flexible polyimide (PI) aerogels for applications in adsorption, filtration, and fire-retardant. Herein, a confinement-controlled freeze-casting method is developed to fabricate PI aerogels with excellent thermal insulation properties by designing multi-scale structural adaptability. In a confinement-controlled system, the enhanced solid/solid and solid/liquid interface interactions in the solution dispersion system induce dendritic evolution of ice crystals. Under the directional freezing, grown dendritic ice crystals squeeze the loaded particles to form polyamic acid salt (PAAs) cryogels. Followed by template removal and thermal imidization, PI aerogels with a micro/nano-scale slit-like porous structure were obtained. The PI aerogels are characterized by ultra-low density (as low as 9.82 mg/cm 3 ) and exceptional thermal insulation performance (25.0 mW/(m·K) at 25 °C).
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 POLYMER SCIENCE
·
2025
·
IF 3.6
Muke Zhang,Yafei Yu,Yang Liu,Liang Chen,Qin Chen,Jinchao Li,Yaping Zhang
Recently, colorless polyimide (CPI) substrates with excellent optical properties, a suitable thermal stability, and a low dielectric constant have become a key factor in the development of wearable and portable flexible electronic devices. A series of branched CPI films has been successfully prepared here by using a self-made triamine (1,3,5-triple (2-trifluoromethyl-4-aminobenzyl) benzene [TFAPOB]). By adjusting the ratio of the cyclopentanone bis-spironorbornane tetracarboxylic dianhydride (CPODA) monomer and the 4,4-(hexafluoroisopropyl)-diphthalic anhydride (6FDA) monomer, an optimal film (CBPI-10) with the highest content of CPODA was obtained. This film could achieve the highest transmittance of 90% at 550 nm and the highest glass transition temperature of 311°C. This result could be explained by the fact that CBPI-10 contained the least amount of trifluoromethyl side groups and the largest amount of alicyclic units, which resulted in the generation of the minimum free volume fraction (according to molecular dynamics simulations) and the disruption of the conjugation effect between the benzene rings. Additionally, it is worth mentioning that the highest dielectric constant of these films was only 2.17, which was significantly higher than those of traditional CPI polymers (2.61–2.72). Consequently, the present study has focused on developing a novel manufacturing scheme for branched CPIs, which is of guidance importance for the design of colorless polymers and the advancement of flexible display technology. Graphical
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
PROGRESS IN ORGANIC COATINGS
·
2025
·
IF 7.3
Sihao Bi,Tong Zhao,Jinghui Tuo,Xiaolong Wang,Ying Sun,Yuantao Zhang
Polyimide (PI) has been widely utilized as an insulating coating material in electrical and electronic packaging applications. Doping fluorinated graphene (FG) into PI can result in a composite insulating coating that combines a high thermal conductivity with a low dielectric constant. To explore the mechanism of the physical property evolution under extreme conditions such as high temperatures, intense electric fields, oxygen-rich, and high-humidity environments, PI neat and PI/FG composite systems were constructed, and molecular dynamics simulations were conducted under the reactive force field (ReaxFF). The results demonstrated that compared with the PI neat system, doping FG into the PI/FG composite significantly increased the thermal conductivity and free volume fraction by 164.7 % and 18.4 %, respectively. Furthermore, FG effectively mitigated the degradation of PI molecules under high temperatures and intense electric fields, reducing the generation of small-molecule degradation products such as CO, CO 2 , H 2 O, and H 3 N. Additionally, FG doping reduced the binding energy with O 2 and H 2 O onto PI molecules, thereby preventing erosion of PI by these species. Finally, a comparative analysis with other studies revealed excellent agreement between the experiments and simulations. This study provides valuable theoretical insights for designing insulating coating materials with enhanced durability and reliability.
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）