ACS Applied Polymer Materials
·
2024
·
IF 4.4
Huijian Ye,Lianlian Chen,Huilei Jiang,Lixin Xu
Dielectric film capacitors have received extensive attention because of their fast release rate and great electrical reliability. A polymer film with large energy density and charge–discharge efficiency is required to expand the application of film capacitors at high temperatures. In this work, a series of ternary fluorinated polyimides (FPI) with different fluorine-containing ratios have been copolymerized to investigate the high-temperature electrical displacements. The fluoro-dianhydride monomer was introduced into the regular 4,4′-diaminodiphenyl ether polymerization system with accompanied thermal imidization. The FPI film exhibits large energy capability with intrinsic breakdown strength compared with pristine PI, which is ascribed to the strong electronegative effect and hydrophobic feature of –CF3 as well as the increase of free volume in bulk. The energy density of optimal FPI film reaches 20.2 J/cm3 at 659 MV/m, and the high-temperature energy storage property is improved, e.g., the energy density up to 11.5 J/cm3 with an external field of 525 MV/m at 100 °C. Low molar polarizability between C–F bonds also contributes to the decreased leakage current, which results in the large charge–discharge efficiency under high temperatures. The PI film with tailored fluorostructure demonstrates the competing candidate for the application of a high-temperature polymer film capacitor.
研究领域:
材料科学
·
电气工程
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DOI
高影响因子
ChemistryOpen
·
2024
·
IF 2.5
Tingyu Song,Yonggang Min
Graphical In this work, 3D-net copper-plated polyimide current collector was prepared through electroless plating method and obtained a structure of PI core and Cu shell. This novel current collector possesses a lightweight areal density. Three different Cu loading copper-coated PI CC samples was prepared and compared. The lithium-ion batteries assembled with Cu-PI CC 2 exhibit better performance. Current collector (CC) is an indispensable constituent in lithium-ion battery (LIB). It plays an important role in supporting electrode materials and conducting electrons between the electrode materials and the external circuit. However, the density of metal CC is high and it hinders the lightweight development of LIB. In this work, lightweight three-dimensional (3D) CC was designed and prepared via a facile electroless plating method. The 3D copper-plated polyimide CC has a low areal density. The 3D structure of Cu-PI CC 2 can facilitate Li + transfer between electrode materials and electrolyte owing to electrolyte can permeate through electrode. Moreover, the lithium titanate anode assembled with the 3D copper-plated polyimide Cu-PI CC 2 exhibited enhanced cycling and rate performance.
研究领域:
材料科学
·
能源技术
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Zhiyun Li,Yizihan Yu,Jiayi Wang,Taowen Dong,Qiushi Zhang,Zhenhai Gao,Weidong Liu,Weitao Zheng
Carbon fibers (CFs) play a pivotal role in electrochemical/mechanical integrated technologies because of their concurrent high specific strength and excellent electrical conductivity. However, the inherently low specific surface area of CFs limits their charge storage capacity, hindering their commercialization in structural–electrochemical integrated systems. Therefore, the primary objective of modifying CF-based electrodes is to significantly enhance their electrochemical performance while preserving their intrinsic high mechanical properties. In this work, a laser-induced processing strategy, as an effective surface engineering tool, was used to optimize polyimide/activated carbon-coated CFs. This approach involves a gradient architecture consisting of a porous graphitized surface layer (shell) that transitions to a densely cross-linked subsurface region (core). This core-shell structure simultaneously enhanced the mechanical and electrical properties of the CF electrode. Moreover, we systematically investigated the laser processing parameters to break the trade-off between the dense protective layer and ion transport kinetics in the core and shell. Consequently, the modified CF electrode showed a 1.3-fold increase in tensile modulus and a 22.3-fold increase in specific capacitance, compared to the pristine counterpart.
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DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2026
·
IF 8.6
Peipei Wang,Fan Ding,Zhaokun Ma,Juan Zhang,Yuhong Liu,Beibei Chen,Zihan Chen,Wei Li
High thermal conductive graphite film (GF) has received great attention in mobile electronic devices, owing to its exceptional thermal conductivity. However, the smooth surface of the GF leads to poor interfacial bonding with the matrix and thus high interfacial thermal resistance, thereby limiting its practical application. To address this issue we proposed a facile and novel cross-stacking strategy to fabricate three different high performance polyimide/GF (PI/GF) composites through thermal compression of modified GF with three different types of soluble PI. Notably, the combination of high-temperature oxidative etching of GF and the introduction of flexible siloxane chains into the PI maximizes the enhancement of interfacial bonding in the composite. This is attributed to the introduced siloxane segments promote the formation of a flexible interfacial layer, which reduces thermal resistance by increasing the contact area while simultaneously improving interlaminar shear strength (ILSS) through stress absorption and dispersion. As a result, the flexible siloxane chain segments polyimide/GF (SPI/GF) composite with a GF volume fraction of 94.5% achieves a high through-plane thermal conductivity of 1543 W/(m·K), along with an ILSS of 1.92 MPa, which represents a 146.2% improvement over the bismaleimide resin/GF (BMI/GF) composite. Therefore, this work provides a facile strategy to enhance interfacial bonding in composites, which concurrently improves both thermal conductivity and mechanical properties, making the materials well-suited for demanding applications such as in aerospace and advanced equipment.
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Hengzhang Dai,Xuan Liu,Chaoran Zhang,Kuang Ma,Yafei Zhang
Particulate matter (PM) pollution can severely affect human health. Currently, the most dangerous air pollutant is PM 2.5 which refers to particles with a diameter less than 2.5 μm. In order to mitigate the detrimental effects of PM 2.5 , there is an urgent demand for an air filter with improved performance. In this study, graphene oxide (GO), polyacrylonitrile (PAN), and polyimide (PI) are combined to prepare PAN/GO/PI nanofibrous membranes for efficient air filtration via electrospinning. The as-prepared PAN/GO/PI-6 nanofibrous membranes demonstrate high filtration efficiency (99.5%), low pressure drop (92 Pa), remarkable thermal stability (300 °C), and excellent mechanical strength. Built upon the above merits, this kind of nanofibrous membrane can account for widespread utilization in both industrial applications and civil health warrants.
研究领域:
材料科学
·
环境科学
·
生物医学工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Xinhai Zhang,Wei Li,Pengyu Song,Bo You,Gang Sun
Polymer-based aerogels have many uses because they possess excellent mechanical properties, such as high moduli and remarkable fatigue resistances. Freeze drying is an appealing aerogel preparation method because it is simple, green and inexpensive. However, polymer-based aerogels prepared by freeze drying always exhibit inferior mechanical properties compared to those prepared by classic supercritical drying, even if the raw material is polyimide . Herein, we report a novel double-cross-linking strategy to obtain a freeze-dried and robust polyimide/reduce graphene oxide/cobalt (PI/rGO/Co) aerogel with an interdigitated cellular architecture. The double-cross-linking strategy was attributed to hydrogen bonds derived from the graphene oxide (GO sheets) and coordination interactions from the Co ions. The interdigitated cellular architecture is the critical factor for achieving aerogels with low densities, flexibilities, high moduli (0.506 MPa compression modulus, 43% improvement of tensile modulus), and high fatigue resistances (1000 cycles). The as-prepared aerogel could be modified to achieve hydrophobicity with a 146.1° water contact angle. It was also difficult to be ignited and it exhibited excellent heat stability and low thermal conductivities (0.040 W·m −1 ·K −1 at 25 °C; 0.046 W·m −1 ·K −1 at 100 °C).
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Applied Materials Today
·
2026
·
IF 7
Siyuan Zhang,Yi Xiang,Liang Chen,Yaping Zhang,Keping Chen,Shuen Liang,Peishuang Xiao,Ningning Song
Polyimide foams (PIFs) are attractive lightweight materials owing to their high mechanical strength, excellent thermal resistance, thermal insulation, and inherent flame retardancy. Nevertheless, the incorporation of crosslinked architectures often leads to a pronounced trade-off between heat resistance and toughness. To address this long-standing limitation, a tetra-functional spirocyclic anhydride is rationally designed and employed as a multifunctional crosslinker to fabricate crosslinked PIFs. The combined effects of spirocycle-induced free volume and crosslinked network result in a refined and homogeneous cellular architecture, with the average cell size reduced from 320 ± 100 μm to 146 ± 49 μm. Benefiting from the synergistic effects of cellular refinement and crosslinking reinforcement, the PIFs exhibit markedly improved mechanical performance, the specific strength, specific modulus and toughness increased to 194 %, 175 % and 245 % of the initial value respectively, together with enhanced fatigue resistance (93.44 % strength retention after 30 cycles). Notably, these performance metrics exceed those of many previously reported PIFs with comparable or even higher densities. Moreover, the introduction of spirocyclic crosslinked structures significantly improved thermal resistance, leading to an increase in glass transition temperature by 62 °C. This work demonstrates an effective dual-enhancement strategy that improves mechanical robustness, toughness and heat resistance of crosslinked PIFs, offering a viable design paradigm for advanced polymer foams operating under extreme conditions.
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Guannan Qian,Li Wang,Yuming Shang,Xiangming He,Shuangfeng Tang,Ming Liu,TuanWei Li,Gaoqiang Zhang,Jianlong Wang
A soluble polyimide (PI) is attempted to be a binder for transition metal oxide cathode in lithium ion batteries . It is synthesized from 2,2-Bis[4-(4-aminophenoxy)phenyl]propane, 4,4′-Oxydianiline and 4,4′-Oxydiphthalic anhydride, and characterized by FT-IR and 1 H NMR techniques. To be a binder, the synthesized PI is applied to fabricate the electrodes, showing binding property and electrochemical performance as good as poly(vinylidene fluoride) (PVDF) that is conventional binder widely used in lithium ion batteries . The 2 Ah pouch full cells with PI and PVDF binders are assembled to compare their performances. As a result, the batteries with PI binder display 91.4% capacity retention after 500 cycles, which is almost the same as the cells withPVDF binder. The overcharge safetytests are carried by 2 Ah pouch full cells, indicating that PI cells can pass the test, no fire and no explosion, but the PVDF cells fail the test, catching fire. The result shows that the PI binder can enhance the safety of Li-ion batteries. This study paves a new way to improve the safety performance of lithium ion batteries .
研究领域:
材料科学
·
储能
·
电化学
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DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 5
·3003-3011
·
IF 3.108
Songlv Qin,Cheng Chen,Mingjun Cui,Afang Zhang,Haichao Zhao,Liping Wang
In this study, to achieve a compatible and good dispersion of graphene in polyimide matrix, we synthesized an aromatic diamine, aniline trimer, as a polymerizable graphene dispersant. Polyimide/graphene nanocomposites with 0.25–2% mass fraction of graphene were prepared by in situ condensation of pyromellitic dianhydride, 4,4′-oxydianiline, and aniline trimer (AT) functionalized graphene in DMAc, following subsequent thermal imidization at elevated temperatures. UV-vis and Raman spectroscopy verified the π–π interactions between AT and graphene. The microstructure analysis using XRD, SEM, and TEM were performed to investigate the morphology of graphene in the polyimide matrix. The thermal, mechanical, and tribological properties of polyimide/graphene nanocomposites were investigated by TGA, DMA, and friction and wear tests. In view of the ease of preparation and their superior physical properties over neat polyimide, PI/G composites prepared in this study showed promising applications as wear-resistant and self-lubricating materials.
研究领域:
材料科学
·
复合材料
·
纳米技术
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产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 31
·期 3
·433-439
·
IF 2.162
Fengmei Cheng,Hao Li,Haidong Li
High dielectric constant is highly desirable in capacitors and memory devices. In this work, oleic acid (OA)-capped BaTiO 3 nanocrystals were synthesized by a two-phase approach. Polyimide (PI)/BaTiO 3 -nanocrystal composite thin films with high dielectric constant have been successfully fabricated. The morphologies and dielectric properties of the hybrid films were exploited. The results showed that BaTiO 3 nanocrystals can be uniformly dispersed in the PI thin films owing to the surface modification of OA-capped BaTiO 3 nanocrystals. It was found that the dielectric constant of composite film varies with the volume fraction of BaTiO 3 nanocrystals and sintering temperatures and reaches a maximum value of 44.1, which is around 13 times higher than that of pristine PI thin film (3.2). These results demonstrated that PI/BaTiO 3 -nanocrystal composite films have considerable application potential in microelectronic fields.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2016
·
IF 3.299
Wenjing Ma,Zhongfu Guo,Juntao Zhao,Qian Yu,Fang Wang,Jingquan Han,Hui Pan,Jianfeng Yao,Qilu Zhang,Sangram Keshari Samal,Stefaan C. De Smedt,Chaobo Huang
In recent years, efficient, cost effective oil-water separation technologies are highly desired due to frequent oil spill accidents. To design fibrous membranes for efficient oil-water separation, ‘flexible’ polyamide acid (PAA), being polyamide acid with ether linkages in the backbone, and ‘heavily’ fluorinated polybenzoxazine (F-PB) were synthesized. Cellulose acetate (CA) and PAA were co-axially electrospun; the PAA core was then imidizated at high temperature to obtain core/shell structured CA/polyimide (PI) electrospun fibrous membranes; subsequently the surface of the fibers was modified with F-PB, in the presence or in absence of silica nanoparticles (SNPs). The mechanical strength, surface wettability, chemical and thermal stability, and oil-water separation potential of thus obtained PI/CA fibrous membranes were evaluated. The membranes show a much higher critical tensile stress (130 MPa) and critical tensile strain (52%), when compared with CA fibrous membranes. Due to the use of the ‘heavily’ fluorinated polybenzoxazine, the membranes are superhydrophobic with a water contact angle of 162° and an oil contact angle which approaches 0°. Interestingly, the newly designed PI/CA/F-PB-1/SNP-4 membranes can effectively separate various oil-water mixtures, solely driven by gravity, with a high flux (3106.2 ± 100 L m −2 h −1 ) and a high separation efficiency (>99%) and thus possess great potential for oil–water separation.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 14
·12205-12211
·
IF 3.201
Qin Wang,Jianling Zhang,Yuyan Yu,Yi Dan,Long Jiang
Aiming to develop a visible-light-driven polymeric photocatalyst that can be fabricated by an easy-to-scale-up polymerization method, a porous polyimide (PPI) with a specific surface area (SBET) of 79.3 m2 g−1 was synthesized by a facile polycondensation of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) with 4,4′,4′′-triaminotriphenylamine (TPA). UV-vis diffused reflection spectroscopy (DRS), electrochemical analysis, valence band X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results reveal that the prepared PPI possesses a narrow band gap (2.04 eV) with the valence band (VB) located at 1.26 V (vs. NHE) and the conduction band (CB) edge at −0.78 V (vs. NHE), clearly indicating the visible light activity of PPI. The photocatalytic performance for the degradation of methylene blue (MB) in water was studied, and the results demonstrate that PPI possesses excellent photocatalytic activity under visible light irradiation. Electron paramagnetic resonance (EPR) and photo-current analyses were used to study the photocatalytic mechanism, which show that PPI has a lot of single electron trapped oxygen and more light-generated electrons. This work may provide a cost-effective, potentially scalable strategy to design and develop a polymeric photocatalyst with continuously tunable photoelectrical properties.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
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