INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Long Ni,Yinfu Luo,Guanchun Wang,Liwei Yan,Haoruo Zhang,Cuiqing Zhou,Shaoyu Qiu,Mei Liang,Shengtai Zhou,Huawei Zou
Flexible polyimide foams (PIFs) with an anisotropic porous structure were prepared by a facile strategy, possessing exceptional mechanical robustness and thermal insulation performances. A comparison of the foaming and rheological behavior, microstructure, and mechanical and thermal and radiation-resistant properties of copolymerized and blended PIFs was conducted. Besides, the formation mechanism of the anisotropic structure and its influence on the mechanical and thermal insulation properties were explored in depth. By reasonably regulating the molecular structure, melt viscosity, melt volatile content, and foaming temperature, a favorable microscopic morphology and structure can be achieved. PIFs with regular porous near-spherical appearance and aligned ellipsoidal strip structures exhibited anisotropic mechanical performance. Meanwhile, PIFs showed anisotropic thermal insulation behavior, which possessed a minimum thermal conductivity (λ) of 0.0314 W/m·K along the pore growth direction (i.e., vertical direction) and a λ as low as 0.0279 W/m·K in the horizontal direction. The anisotropic thermal conduction behavior endowed PIFs with intelligent thermal protection and infrared stealth performance. In addition, the PIFs presented an exceptional thermal stability and compressive strength retention rate after experiencing a radiation dose of 10027.5 kGy. Therefore, a facile strategy for rapid fabrication of PIFs that can be positioned for structural design, thermal insulation, and radiation-resistant applications in high-end engineering sectors was proposed.
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高影响因子
ACS Applied Energy Materials
·
2026
·
IF 5.5
Wang Jiaxuan,Zhang Tongtong,Kawi Sibudjing,Li Yinhui
The development of high-energy-density lithium-metal batteries (LMBs) has imposed increasingly stringent requirements on the thermal stability, ionic conductivity, and interfacial compatibility of separators. To address the inherent drawbacks of conventional polypropylene (PP) separators, such as inadequate thermal stability and poor electrolyte wettability, a polyimide (PI) separator was fabricated via the nonsolvent induced phase separation (NIPS) method in this work. Furthermore, by introducing metal-organic framework (MOF) materials (UiO-67) into PI slurry, a PI/UiO-67 composite separator was successfully constructed, which achieves the synergistic optimization of the pore structure, surface morphology, and mechanical properties of the separator. The results demonstrate that the PI/UiO-67 composite separator retains the excellent thermal stability of the PI matrix, with no thermal shrinkage observed at 200 ° C, while simultaneously exhibiting significantly improved electrode–electrolyte interfacial compatibility. Compared with the commercial PP separator (bulk resistance 2.97 Ω, interfacial impedance 165 Ω), the composite separator possesses a lower bulk resistance (2.28 Ω) and interfacial impedance(122 Ω). Additionally, integrating UiO-67 considerably improves the wettability of the electrolyte and the lithium-ion transference number (0.61) in the separator, which in turn markedly boosts the electrochemical stability and the long-cycle performance of LMBs. LMBs utilizing the PI/UiO-67 separator achieve a notable capacity retention of 87.4% after 150 cycles at a rate of 0.5 C. In tests conducted with lithium symmetric cells, stable cycling performance is observed for more than 600 h at a current density of 0.2 mA cm –2 . This study offers a valuable composite approach and theoretical insights for advancing the development of separators that ensure high safety and performance in LMBs.
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MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 45
·期 3
·2300502
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IF 4.6
Hang Fan,Tiantian Xie,Yang Pang,Shiyang Zhu,Pengju Feng,Xuanbo Zhu,Chengji Zhao,Shaowei Guan,Hongyan Yao
Excessive swelling is one important factor that leads to high fuel permeability and limited operating concentration of methanol for proton exchange membranes. Herein, a collaborative strategy of main-chain and molecular-network engineering is applied to lower swelling ratio and improve methanol resistance for highly sulfonated polyimide. Two m -phenylenediamine monomers (4-(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene-1,3-diamine and 4,6-bis(2,3,5,6-tetrafluoro-4-vinylphenoxy)benzene-1,3-diamine) with tetrafluorostyrol groups are designed and synthesized. Two series of cross-linked sulfonated polyimides (CSPI-Ts, CSPI-Bs) are prepared from the two diamines, 4,4′-diaminostilbene-2,2′-disulfonic acid and 1,4,5,8-naphthalenetetracarboxylicdianhydride. The rigid main-chain structure is cornerstone for wet CSPI-Ts and CSPI-Bs remaining stable at elevated temperatures. The introduction of hydrophobic cross-linked network further improves their dimensional stability and methanol resistance. CSPI-Ts and CSPI-Bs show obviously improved performances containing high proton conductivity (121 ± 0.27–158 ± 0.35 S cm −1 ), low swelling ratio (9.6 ± 0.40%–16.1 ± 0.01%) and methanol permeability (4.14–7.69 × 10 −7 cm 2 s −1 ) at 80 °C. The direct methanol fuel cell (DMFC) is assembled from CSPI-T-10 with balanced properties, and it exhibits high maximum power density (PD max ) of 82.3 and 72.6 mW cm −2 in 2 and 10 m methanol solution, respectively. The ratio of PD max in 10 m methanol solution to the value in 2 m methanol solution is as high as 88%. The CSPI-T-10 is promising proton exchange membrane candidate for DMFC application.
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PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2023
·
IF 9.2
Jinchao Li,Huiting Li,Haorui Duan,Jun Long,Wenheng Huang,Yafei Yu,Wenjie Zhu,Liang Chen,Jijun Chen,Yaping Zhang
In this paper, a new functional diamine monomer 2-methyl-1,4-bis(4-amino-2-trifluoromethyl) benzene (FAPOB) is designed and synthesized for further improving the performance of branched sulfonated polyimide (SPI–B) membrane for implementation in vanadium redox flow battery (VRB). At the same time, the sulfonation levels of SPI-B membranes are accurately regulated by modifying the proportion of FAPOB and 4,4′-diaminobiphenyl-2,2′-disulphonic acid. Among them, the SPI-B-50 membrane with 50 % sulfonation degree exhibits a remarkable proton selectivity of 2.31 × 10 5 S min/cm 3 , which is 5.5 times higher than the Nafion 212 (NR212) membrane. Moreover, the SPI-B membrane's stability is significantly improved due to its branched structure and the presence of numerous trifluoromethyl groups . Compared to NR212 membrane, SPI-B-50 membrane demonstrates superior coulomb and energy efficiencies at the same current density . Furthermore, the SPI-B-50 membrane exhibits a higher voltage holding capacity compared to the NR212 membrane. Remarkably, the SPI-B-50 membrane maintains stable efficiencies even after undergoing more than 500 charge-discharge cycles. This research not only involves the innovative synthesis of a novel diamine monomer but also the construction of various SPI-B membranes with a unique molecular structure specifically designed for VRB applications.
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高影响因子
Journal of Materials Chemistry B
·
2023
·
IF 7
Zhaoying Wu,Rames Kaewmanee,Qianwen Yang,Zimin Wang,EN Xie,Jie Wei,Chao Zhang
Polymer-based composites possess some outstanding advantages over ceramic/metallic/polymeric biomaterials, which is considered as a promising candidate for bone repair. Tantalum (Ta)/polyimide (PI) biocomposites (PT) containing Ta nanoparticles of 20 v% (PT20) and 40 v% (PT40) were fabricated, and luteolin (LU) was loaded on PT40 (LUPT40). Compared with PT20 and PI, PT40 with high Ta content displayed high surface behaviors (e.g., roughness, surface energy, and hydrophilicity). PT40 remarkably improved the cell adhesion and multiplication, and LUPT40 with LU displayed further enhancement in vitro. Moreover, LUPT40 obviously boosted osteoblastic differentiation while suppressed the osteoclastic differentiation. Furthermore, LUPT40 exhibited good antibacterial effects because of the slow release of LU. The in vivo results confirmed that PT40 markedly promoted bone-formation, and LUPT40 further enhanced bone-formation/bone-bonding. In short, incorporation of Ta particles improved surface behaviors of PT40, which stimulated cell-response/bone-formation. Moreover, the slow release of LU from LUPT40 not only promoted cell-response/bone-formation but also enhanced bone-bonding. The synergistic effects of Ta and LU release from LUPT40 enhanced bone-formation/bone-bonding. Therefore, LUPT40 would have great potential for repair of bear-loading bone.
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PubMed
高影响因子
Journal of Cleaner Production
·
2023
·
IF 11.1
Shiwei Chen,Yonghao Hu,Dongfang Gao,Chaofeng Zhu,Bing Li,Zhenhua Wang,Xinjing Pan
Aiming to realize sustainable development and reduce environmental pollution , scientists have been on searching for bio-based materials derived from renewable resources to replace petroleum-based materials. Herein, a bio-based polyimide aerogel derived from 2,5-furandicarboxylic acid was synthesized successfully via supercritical fluid drying. The bio-based polyimide aerogel had mesoporous structure and a large specific surface area (220 m 2 /g), which were highly advantageous to adsorption and photocatalysis . The bio-based polyimide aerogel possessed fast adsorption behavior (within 1 s), outstanding durability (200 cycles of adsorption and desorption), and a self-cleaning property. The bio-based polyimide aerogel could also realize continuous and rapid separation of organic solvent and water with the aid of a vacuum pump. Importantly, the bio-based polyimide aerogel exhibited superelastic (rapid recovery after 90% strain) and anti-fatigue performance (compressive strength remained 96% after 100 cycles). Moreover, the bio-based polyimide aerogel displayed effective photocatalytic activity under visible light. The possible degradation mechanism was also proposed, and radical quenching tests demonstrated that the generation of h + and ·O 2 − was the key to photocatalytic degradation . Considering its environmental friendliness and excellent properties, bio-based polyimide aerogel provides a promising solution for oil/water separation and photocatalysis.
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Shutian Liu,Conglin Dong,Chengqing Yuan,Xiuqin Bai,Ye Tian,Guoliang Zhang
Stabilizing friction force of polymer composites’ wear interfaces during frictional processes is useful to suppress or eliminate the friction-induced chatter and noise behaviors in low velocity. A new Polyimide (PI) matrix composite material composed of Polyimide and MoS 2 nano particles was fabricated and tested. The experimental wear tests were conducted to investigate relationship between friction forces, friction-induced chatters and noises under dry and water conditions in low friction velocity . The typical tribological properties of modified composite and some typical mechanical properties were analyzed to reveal the mechanism of MoS 2 nano particles on frictional behaviors reduction. The results showed that the transformations and formations of MoS 2 tribo-film presented excellent COF reduction on modified PI composite by more than 50%, and also could effectively reduce PI deformations on wear surface which obviously decreased friction forces and their fluctuating amplitudes. These cases endowed the modified PI composite excellent performances on friction-induced chatter and noise reductions compared to the pure PI even though some mechanical properties were weakened. The understanding gained herein is helpful for comprehending the friction-induced chatter reduction of the MoS 2 filler on polymer matrix composites and future designing of polymer matrix composites with low friction and good chatter and noise reductions in low friction velocity.
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高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 7
·2100086
·
IF 4.367
Tangjian Cheng,Genpin Lv,Yitao Li,Hao Yun,Lingfei Zhang,Yongmao Deng,Liping Lin,Xiangjun Luo,Junmin Nan
The low dielectric polymer films have drawn great attention to the application as the dielectric insulating materials in high-frequency circuit boards, while the weak adhesion to the copper foils and the poor processability resulted from the fluorinated or rigid structures limited their high-frequency application. In this work, the low dielectric and high adhesive polyimide/fluorinated ethylene propylene (PI/FEP) nanocomposite film for high-frequency flexible circuit board application is developed. It is indicated that the fluorocarbon surfactants can significantly improve the dispersion of FEP in PI substrate, and thus, the PI/FEP nanocomposite film exhibits excellent mechanical properties, including the tensile strength increases to 46.6 MPa and the elongation at the break increases to 13.7%. Importantly, at the high-frequency of 10 GHz, the 60 wt% FEP filled PI nanocomposite film displays an ultralow dielectric loss (0.006) and a reduced dielectric constant (2.69). In addition, the high-frequency flexible circuit board with the PI/FEP film as the dielectric insulating layer has a high peel strength of 0.75 N mm −1 , indicating this PI/FEP nanocomposite film can meet the requirements of the high-frequency flexible circuit board application.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2021
·
IF 8.742
Jun Long,Wenjie Xu,Shoubin Xu,Jun Liu,Yanlin Wang,Huan Luo,Yaping Zhang,Jinchao Li,Liangyin Chu
The development of a vanadium redox flow battery (VRFB) urgently requires proton conductive membranes with high proton selectivity. Herein, we synthesized branched anhydride monomer 1,3,5-tris(3,4-anhydride phenoxy)benzene using a three-step method. Furthermore, we prepared successfully novel double branched sulfonated polyimide (dbSPI) membranes with ultra-low vanadium ion permeability (0.4–2.5×10 −8 cm 2 min −1 ), one or two orders of magnitude lower than that of the Nafion 212 membrane (7.25×10 −7 cm 2 min −1 ). Among all membranes, the dbSPI-50 membrane with the highest proton selectivity (23.25×10 5 S min cm −3 ), approximately 68 times higher than that of the Nafion 212 membrane, was chosen for assembling of a VRFB single cell. Because of its ultra-low vanadium ion permeability, the dbSPI-50 membrane exhibited much longer self-discharge time (97 h) and superior capacity retention (82.6–91.3%) compared with the Nafion 212 membrane. Moreover, both coulomb efficiency (99.6–98.5%) and energy efficiency (69.3–80.1%) of the dbSPI-50 membrane are higher than those of the Nafion 212 membrane after 300 times charge-discharge tests at a current density from 200 to 100 mA cm −2 . All these results demonstrate that the optimized dbSPI-50 membrane is a promising candidate for applications in VRFBs.
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高影响因子
PROGRESS IN ORGANIC COATINGS
·
2020
·
IF 4.469
Zian He,Junwen Xie,Ziwei Liao,Yingyi Ma,Mingyan Zhang,Wenlong Zhang,Hongyan Yue,Xin Gao
Low-dielectric-constant materials are in great demands to satisfy the requirements in microelectronics. In this study, polyhedral oligomeric silsesquioxanes (POSS) contained hierarchical porous structure, which was prepared by the self-assembly of water droplets, was used as a coating for flat polyimide (PI) film. Evident declines were found in dielectric constant and water uptake upon the introduction of the hierarchical porous coating due to the existence of fluorine-containing groups, POSS and the hierarchical porous structure. In addition, almost undamaged mechanical properties were shown when the dielectric and water resistance properties were optimized because the hierarchical porous structure was used as a coating but not the bulk of the PI film. When the content of POSS varies from 10 % to 50 %, low dielectric constants of 2.42–2.75 and low water uptakes of 0.60 %– 0.67 %, with 22 %–27.63 % and 75.96 %–78.43 % of reductions were obtained, compared to 3.36 of dielectric constant and 2.80 % of water uptake for flat PI film. More importantly, the stability of dielectric properties in humid environment was verified by only 2.94 %–4.83 % of increase in dielectric constant after exposing to high humidity for more than 25 h, compared to 9.43 % of increase for flat PI film. The present study provides a versatile method for the preparation of low-dielectric-constant polymer materials with comprehansive properties.
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高影响因子
POLYMER
·
2021
·
IF 4.43
Long Ni,Yinfu Luo,Xionghou Peng,Shengtai Zhou,Huawei Zou,Mei Liang
Polyimide foam (PIF) has been extensively used as structural and thermal insulation materials. Five semi-rigid PIFs with different diamine structures were fabricated by unrestricted foaming process with polyester ammonium salt (PEAS) precursor powders. All PIFs exhibited a nearly homogeneous spherical closed pore structure with an average pore size of 123–335 μm and a high closed-cell rate (87.4–95.5%). Results indicated that the molecular structure, melt viscosity and foaming temperature were important factors that affected the foaming process and pore structure. The values of 10% compression strength of PIFs at both 25 and 200 °C were in the range of 0.16–0.35 and 0.09–0.16 MPa, respectively, with PIF BTDA-MDA and PIF BTDA-DMBZ exhibiting the best mechanical performance. All PIFs exhibited outstanding thermal stability, with glass transition temperatures of 312–378 °C and 5% weight loss temperatures of 504.5–564.5 °C in nitrogen and 501.8–562.0 °C in air, respectively. The prepared PIFs exhibited extremely low thermal conductivity and thermal diffusivity , which can be used as thermal insulation materials. Based on above findings, the prepared semi-rigid PIFs demonstrate a great potential for being utilized as thermal insulation and structural support materials in high-tech fields such as aerospace, marine transportation, and microelectronics.
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高影响因子
Advanced Composites and Hybrid Materials
·
2021
·Vol. 4
·期 4
·1102-1112
·
IF 5.693
Zhang Xiaodong,Dong Jingwen,Pan Duo,Yang Gui,Su Fengmei,Ji Youxin,Liu Chuntai,Shen Changyu
A major issue limiting the thermal conductivity (TC) of polymer-based composites is the inevitable vacancy among thermal conductive fillers; the fabrication of continuous thermal conductivity network is significant. In this work, we successfully constructed interpenetrating carbon nanotube (CNT) @carbonized polyvinyl alcohol (αPVA) network in polyimide (PI)/boron nitride nanosheets (BNNS) membranes through co-electrostatic spinning of polyamide acid (PAA)/BNNS precursor fibers and PVA/CNT precursor fibers and subsequent high-temperature treatment. The CNT @αPVA network works as a continuous thermal conductivity network in the membrane, which could also bridge BNNS to remove the vacancies among BNNS fillers. Due to the formation of dual thermal conductive networks, the TC of PI/BNNS with 30 wt% BNNS reached an increasement of 100% with the addition of only 0.3 wt% CNT. In addition, the composites present electrical insulating properties with volume resistivity of about 10 15 Ω·cm, as well as excellent flexibility, pretty good acid–alkali tolerance, and self-extinguishing. This work provides an effective way to develop continuous thermal conductive networks in polymer-based composites for scalable thermal management applications in microelectronics devices. Graphical abstract
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高影响因子
危险品化学品经营许可证（带存储）