ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Bin Jiang,Hongting Pu,Haiyan Pan,Zhihong Chang,Ming Jin,Decheng Wan
Fluorine-containing polyimide (FPI) with hydroxyl groups is synthesized from 4,4′-(hexafluoro isopropylidene) diphthalic anhydride (6FDA), 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (6FAP), and 4,4′-diaminodiphenyl ether (ODA) via high temperature polycondensation . Thereafter, alkynyl groups are introduced into FPI. During the preparation of the composite membrane, alkynyl groups on FPI react with azido methyl of 4,4′-bis(azido methyl) biphenyl via click chemistry and form semi-interpenetrating polymer network (semi-IPN) structure within the composite membranes. The mechanical properties, thermal behavior, water uptake, swelling ratio, proton conductivity, oxidative stability, as well as the performance in single cell operation are investigated. Compared to pure perfluorosulfonic acid (PFSA) polymer membrane, the composite membranes based on semi-IPN of FPI and PFSA exhibit improved mechanical properties, excellent thermal and dimensional stabilities, and suitable proton conductivity. The tensile strength of the composite membranes ranges from 28.0 to 67.0 MPa. With increasing FPI content in the membranes, the dimensional stability of the composite membranes increases. The composite membranes have the proton conductivity from 4.3 × 10 −2 S·cm −1 to 1.0 × 10 −1 S·cm −1 at 100 °C and also have good performances as proton exchange membrane (PEM) in single cell at 80 °C.
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Nano Energy
·
2024
·
IF 16.8
Wasim Akram,Qian Chen,Xunlong Zhang,Song Ren,Li Niu,Jian Fang
Energy harvesting yarns working on triboelectric effect by converting mechanical energy into electricity for running wearable electronics as well as operating as self-powered sensors, are superb choices for wearable electronics of current and future generations. However, current yarn-based triboelectric nanogenerators (TENGs) designed through electrospinning process are limited in achieving higher outputs, comfort, mechanical strength, washability, and industrial scalability. In this study, we introduce a flexible and durable tribonegative yarn TENG (TNY) with an electrospun polyimide (PI) intermediate charge trapping layer between the electrode and electrospun superhydrophobic polyvinylidene difluoride (PVDF)/Poly(dimethylsiloxane) (PDMS). In this coaxial arrangement, the PI charge entrapment layer enabled the TNY to exhibit an output voltage of 14 V in a 2.5 cm length, compared to only 8 V for TNY without PI layer. The TNY can be successfully woven and knitted into electronic textiles (E-Textiles), with their outputs compared based on various knitted and woven patterns. The E-Textile maintained considerable outputs after washing and withstood 5000 Martindale abrasion cycles. The superhydrophobic behavior also enabled TNY to harvest water energy from a running tap. We demonstrated the potential of these E-Textiles for edge ball sensing in cricket sports in real-time by leveraging the benefits of triboelectrification, thereby avoiding the need for complex camera setups and sound systems for judging ball movements at ± 140 km/hr in real sports. We also employed E-Textiles for smart switch functions, which can be beneficial in smart systems. This study demonstrates the improved performance of yarn-based TENGs and further extends the applications of TENGs in sports analysis. It provides a facile and high-efficiency approach for designing triboelectric sensors, offering a cost-effective alternative to complex and expensive sports equipment.
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EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Tianyong Zhang,Yamei Chai,Suisui Wang,Jianing Yu,Zihao Fang,Shuang Jiang,Bin Li
With the diminishing gap between the internal components of chips, the signal transmission delay poses a substantial threat to chip performance. To enhance the transmission speed of electrical signals, the development of materials with a low dielectric constant (D k ) becomes imperative. Polyimide (PI), categorized as a specialized engineering material, exhibits a high D k (≥3), posing challenges in meeting the requirements of electronic and communication industries. Consequently, a new diamine monomer named BTVFD, characterized by spirobifluorene and cross-linkable tetrafluorostyrol groups, was synthesized. It was copolymerized with 2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diamine (TFDB) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to synthetize cross-linkable polyimides (TBPIs) with different BTVFD content. The cross-linked TBPIs (CL-TBPIs) were obtained by thermal cross-linking reaction. The study results demonstrate the D k of PIs is significantly reduced through this effective strategy. Notably, CL-TBPI-2 exhibits outstanding comprehensive performance with low D k (1.88@10 MHz) and dielectric loss (0.00513@10 MHz), low water uptake (0.125 %), high thermal decomposition temperature (5 % weight loss at 553 °C) and glass transition temperature (374 °C), excellent tensile strength (121.8 MPa) and nice transparency and flexibility.
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POLYMER
·
2024
·
IF 4.1
Long Ni,Yinfu Luo,Cuiqing Zhou,Haichao Meng,Guanchun Wang,Liwei Yan,Mei Liang,Shaoyu Qiu,Shengtai Zhou,Huawei Zou
Flexible polyimide foams (PIFs) demonstrate a great potential for applications in the fields of thermal insulation, flame retardancy and irradiation tolerance. In this work, mechanically flexible PIFs with anisotropic pore structure were prepared by adopting the copolymerization strategy and microwave-assisted foaming process. The copolymerization reaction was conducted to synthesize polyester ammonium salt (PEAS) precursors using 3,3′,4,4′-benzophenone tetracarboxylic acid dianhydride (BTDA) as dianhydride, 4,4′-diaminodiphenyl ether (ODA) and 4,4′-diaminodiphenyl sulfone (DDS) as the copolymerized diamines; afterwards, PEAS powders with particle sizes ranging from 100 to 300 μm were obtained by drying, crushing and sieving treatments, which were used as the feedstock for “bottom-up” microwave-assisted foaming and thermal imidization process, thereby leading to the formation of PIFs with regular three-dimensional near-spherical pores in vertical direction (parallel to the pore growth direction) and the aligned ellipsoidal strip-like pore structure in horizontal direction. The directional growth of foam pores resulted in anisotropic mechanical flexibility and thermal insulation performance. Moreover, PIFs possessed excellent thermal stability and flame retardancy with the initial thermal degradation temperature higher than 545 °C and limited oxygen index up to 58.8%. The PIFs exhibited exceptional thermal insulation performance with thermal conductivity values ranging from 0.0276 to 0.0517 W/(m·K) between 25 and 300 °C. Additionally, the PIFs demonstrated excellent irradiation tolerance, with the mechanical and thermal stability retention rate being above 96% after the irradiation experiment (radiation dosage: 1.15 × 10 5 Gy) using 60 Co source. Thus, lightweight PIFs with superior high temperature thermal insulation performance, flame retardancy and irradiation tolerance were successfully prepared, which showed potential applications in aerospace, medical and nuclear power sectors.
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ACS Applied Polymer Materials
·
2025
·
IF 4.7
Shiying Qi,Shuo Han,Jianhao He,Jianchao Jiang,Chi Zhang,Jun Wang,Fei Xiao,Yuanrong Cheng
Herein, an effective design strategy is utilized to simultaneously reduce two difficult-to-reconcile indexes in polyimide (PI): the dielectric constant (Dk) and dielectric loss (Df). It is realized by the synthesis of cross-linked PIs using a bulky and cross-linkable diamine, (4,4′-(4-(4-(2,3,5,6-tetrafluoro-4-vinylphenoxy)phenyl)pyridine-2,6-diyl)dianiline) (TFVPPDA), featuring bulky triphenylpyridine and cross-linkable tetrafluorostyrol pendant groups. And copolymerized with 2,2′-bis(trifluoromethyl)benzidine (TFDB) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) to synthesize cross-linkable PIs (co-FPIs: co-FPI-10, co-FPI-20, and co-FPI-30) with varying TFVPPDA content. Then, cross-linked PIs (co-FPIs-CL: co-FPI-10-CL, co-FPI-20-CL, and co-FPI-30-CL) were obtained by thermal cross-linking reactions. The cross-linked PIs with cross-linked networks possess more free volume compared with the corresponding uncured PIs, thus further reducing the Dk. Additionally, cross-linked networks restrict the deflection of polar imide groups in the polymer chain, leading to a relatively low Df. More importantly, this design strategy effectively retains the excellent thermal, mechanical, and low moisture absorption properties of the PIs. Notably, co-FPI-30-CL has a low Dk (2.50) and Df (0.0060) at a high frequency of 10 GHz, a glass transition temperature (Tg) of 384 °C, a 5 wt % decomposition temperature (Td5%) of 566 °C, a low coefficient of thermal expansion (CTE) of 41.5 ppm/°C, a high tensile strength (σmax) of 123.3 MPa, and a low moisture absorption rate (Wa) of 0.11%.
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Advanced Materials Technologies
·
2024
·Vol. 9
·期 12
·2302168
·
IF 6.4
Zhitao An,Wentao Li,Quan Pei,Yiting Tong,Chongxin Liu,Qingfeng Zhang,Shuhong Xie,Jing Chen
Polyethylene oxide composite electrolytes are widely used in lithium-ion batteries because of their excellent moldability, good flexibility, and favorable chemical compatibility. However, they still suffer from low ionic conductivity and weak mechanical strength. Herein, a 3D nanofiber-reinforced dual-salt composite solid electrolyte (PI@PCB) is synthesized. Benefiting from the support of the porous polyimide films and the addition of lithium bis(oxalate)borate, the obtained PI@PCB electrolyte exhibits high mechanical strength, good thermal stability, excellent electrochemical stability, and a high lithium ion transference number (0.70). In addition, the assembled Li/PI@PCB/Li cell shows the lowest overpotential of 200 mV at the initial cycling stage and increases to 246 mV slightly after 1500 h. The capacity retention rate of Li/PI@PCB/LFP battery is about 88.3% after 500 cycles at 60 °C.
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JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yidan Ding,Mengjiao Xia,Jian Yu,Erqiao Chen,Congcong Zhou,Liguo Shen,Yang Jiao,Yanchao Xu,Hongjun Lin
Mixed matrix membranes (MMMs) incorporating ZIF-8 nanoparticles through non-solvent induced phase separation (NIPS) hold great potential in the organic solvent nanofiltration (OSN) field, but their advancement and application have been significantly hindered by ZIF-8’s instability of ZIF-8 in aqueous conditions and major interfacial incompatibilities with polymers. This study presents an approach to overcome these obstacles by initially forming crosslinked ZnO/polyimide (PI) MMMs via NIPS and crosslinking processes, followed by in-situ conversion of ZnO to ZIF-8 within the membrane structure. This method prevents direct contact of ZIF-8 with water, optimizes the interface between ZIF-8 and the polymer, and modulates the pore structure of the membranes. The resulting crosslinked ZIF-8/PI membranes exhibit an ultra-high ethanol permeance of 42.7 L m⁻ 2 h⁻ 1 bar⁻ 1 and a 99.5 % rejection of Rose Bengal dye, surpassing the performance of all state-of-the-art OSN MMMs to our knowledge. Additionally, these membranes also demonstrate excellent separation performance in harsh solvents such as DMF and NMP. The findings of this study not only significantly advance the development of OSN membranes but also offer insights into the optimization of membrane fabrication techniques, setting a new benchmark for the design of high-performance OSN membranes.
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Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 48
·33632-33639
·
IF 10.7
Xingwu Jiang,Xiang Wang,Peifeng Liu,Jinzheng Huang
Polyimide (PI), a kind of polymer with excellent heat resistance, processing, mechanical and electrical insulation performance, stands out as a prime candidate for advanced dielectric energy storage materials. However, the low dielectric constant of PI has hindered its broader development, requiring dielectric modification. In order to increase the dielectric constant of PI, PI with a polar trans-cyclohexane structure was synthesized and characterized and then reinforced with nano-C@BT-fibers to produce a novel nanofiber reinforced PI film. Experimental results demonstrate that polar trans-cyclohexane enables pure PI films to achieve a dielectric constant of 8.89 at 100 Hz. Meanwhile, the dielectric constant of C@BT-fibers/modified PI composite films was indeed increased up to 39.48 at 100 Hz and the energy storage density increases to 1.028 J cm−3 with only 1.0 wt% addition content of C@BT-fibers, increased by 117.3% compared with that of pure PI (0.473 J cm−3).
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Fuying Pei,Bohan Yin,Hongge Jia,Lijia Liu,Yutong Shan,HongjinWang
The development of multifunctional nanofiber membranes with high separation efficiency for the simultaneous removal of oil–water emulsions and organic dyes is essential due to the complexity of hazardous components in real wastewater. Herein, a polyimide (PI) fiber membrane prepared by electrospinning was carboxylated and used to simultaneously separate oil-in-water emulsions and methylene blue (MB) dye for the first time. A superhydrophilic/underwater oleophobic electrostatically spun carboxylated polyimide (Cx-PI) fibrous membrane was successfully prepared through electrostatic spinning, thermal imidization, and alkaline hydrolysis to construct carboxyl and imide groups on the polyimide fibrous membrane. The resulting membranes exhibited excellent performance in gravity-driven separation for the effective removal of oil, oil-in-water emulsions, and MB dye. The separation efficiency was ≥ 99.4 % for oil-in-water emulsions stabilized with various surfactants with a flux of up to 1128.5 L m −2 h −1 . In addition, the oil and dye in the emulsion could be simultaneously separated with an emulsion separation efficiency of ≥ 99.2 %, a flux of about 910.6 L m −2 h −1 , and an MB dye removal rate of 98.6 %, even when the MB dye concentration was as high as 100 mg/L. The Cx-PI nanofiber membrane also demonstrated excellent stain resistance, salt resistance, high-temperature resistance, and mechanical durability. The above results indicated that the Cx-PI membranes were suitable for the separation of oil-in-water emulsions containing MB dyes under complex conditions. This study provides a promising application in solving the global water pollution caused by oily organic solvents and water-soluble dyes.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Ao Tang,Zhuo Chen,Huijie Nie,Jie Dong,Xin Zhao,Xiuting Li,Qingsong Xu,Qinghua Zhang
A series of highly selective polyimide gas separation membranes were successfully synthesized by reacting the newly synthesized dianhydride monomers containing the amide unit and benzyl group with a commercial diamine, 1,3,5-trimethyl-2,4-phenylenediamine (DAM). The combination of the intermolecular hydrogen-bonding interaction from the amide-imide backbone and the thermo-oxidative cross-linking network induced by the benzyl units endows the membrane with a strong size-sieving capability with an ideal CO 2 /CH 4 selectivity > 125 (over six times higher than that of the commercial Matrimid 5218) with a moderate CO 2 permeability, ranking the top among that of the polyimide gas separation membranes reported so far. The comprehensive separation performance for the CO 2 /CH 4 gas pair surpasses the state-of-the-art 2008 upper bound. Moreover, the prepared membrane showed an increased stability toward high CO 2 pressure of 12 bar, demonstrating an excellent plasticization resistance due to the tightened molecular packing and confined molecular chain motion as well as the rigid nature of the polymer backbone, which also enabled high glass transition temperatures (>400 °C) and fine mechanical properties (tensile strength > 52 MPa) as well as an anti-aging property of the prepared membranes. This study provides a reliable route for constructing polymer membranes with an accurate gas molecular sieving ability and high durability.
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高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2025
·
IF 8.9
Zhilin Chen,Xianbo Hou,Jia Chen,Shuyan Nie,Shaowei Zhu,Tao Liu,Liming Chen
Aerogel fibers have exhibited crucial application prospects in wearable heat-insulated fabrics. However, developing aerogel fibers with robust mechanical performance and high flexibility remains challenging due to their inherent fragility caused by high porosity. Herein, aramid nanofibers (ANF) reinforced polyimide (PI) aerogel fibers (ANF/PIAFs) are presented with tunable in situ core-sheath structure for super-flexible and super-toughness wearable heat-insulated fabrics by a novel two-step (2Step) phase separation strategy. The results demonstrate that the formation of sheath thickness and pore morphology of aerogel fibers can be tuned by the phase separation steps. Attributed to the core-sheath structure and the entanglement of chains with the introduction of ANF nanofibers, the tough and flexible ANF/PIAFs demonstrate improved tensile modulus (748.53 MPa), tensile strength (51.94 MPa) and fracture energy (18.28 MJ/m 3 ) by 2.5 times, 11.5 times, and 288.2 times compared with the unprocessed PI aerogel fibers. Moreover, the addition of ANF effectively inhibits the shrinkage of aerogel fibers, which maintains the high thermal insulation ability (0.034 W/(m·K)). The strategy outlined in this study introduces a novel and universal method for fabricating aerogel fibers with a core-sheath structure using the improved phase separation technique, demonstrating the promising potential for applications in flexible thermal-insulated fabrics.
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ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 31
·2201496
·
IF 19.924
Yue Huang,Shujie Liu,Qiaojing Chen,Kejin Jiao,Bin Ding,Jianhua Yan
Solid electrolytes are being considered as an effective solution to replace liquid ones for building safer batteries, but they suffer either low ionic conductivity or large contact ohmic impedance. Here, a highly conductive and thermomechanically stable quasi-solid electrolytes (QSE) by self-polymerization of a commercially available liquid electrolytes (1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), lithium trifluoromethane sulfonimide (LiTFSI) and LiPF 6 ) at room temperature in a porous polyimide nanofiber film are reported. LiPF 6 initiates the ring-opening reaction of DOL and LiTFSI promotes the self-polymerization to form poly-DOL (PDOL), while the plasticizer of DME solidifies the PDOL. On the other hand, polyimide has a great affinity with PDOL that facilitates to form stable QSE network. As a result, the QSE film shows a high room-temperature ionic conductivity of 2.9 × 10 −3 S cm −1 , a high mechanical strength of 31 MPa, and high heat resistance to 160 °C. The LiFePO 4 ||QSE||Li batteries with a high cathode loading of ≈18.7 mg cm −2 show great cycling performance and stable electrode/electrolyte interfaces at a high current rate of 0.5 C with a capacity retention of 91.8% over 200 cycles at room temperature.
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危险品化学品经营许可证（带存储）