POLYMER DEGRADATION AND STABILITY
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2026
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IF 8.1
Hongbo Zhao,Wenzhuo Qiu,Zihao Wang,Qianyun Zhong,Jie Wei,Xilei Chen,Chuanmei Jiao,Shaofeng Wang
The development of lightweight polymer foams with enhanced thermal stability and fire safety is highly desirable for applications in harsh environments. However, simultaneously improving flame retardancy, thermal protection, and multifunctional capabilities remains challenging due to the complex interplay among polymer degradation, combustion behavior, and structural stability. Herein, multifunctional polyimide foams were fabricated via a facile isocyanate-mediated one-pot strategy by introducing synergistic carbonaceous components, including graphene oxide (GO), carbon black (CB), and carbonized iron–cobalt–nickel Prussian blue analogue derivatives (CPBA), into the polyimide matrix during foam formation. The incorporation of these components effectively modulated the thermal degradation behavior and combustion characteristics of the polyimide foam by constructing interconnected carbon networks, heterogeneous interfaces, and catalytic active sites. Compared with pristine polyimide foam, the composite foam exhibited improved fire safety, with a 23.2% reduction in peak heat release rate, a 55.68% decrease in total smoke production, and a 29.82% increase in char residue. TG-IR analysis and residual char characterization revealed that the enhanced flame-retardant performance was attributed to the synergistic suppression of volatile degradation products and the formation of compact protective char layers. Furthermore, the porous composite structure provided improved thermal insulation, limiting the back-surface temperature increase to only 13.2 °C after heating at 120 °C for 210 s. Meanwhile, the optimized composite foam retained excellent microwave absorption performance, achieving a minimum reflection loss below −40 dB and a maximum radar cross-section reduction of 23.18 dB·m 2 . This work provides new insights into the regulation of polymer degradation behavior through carbon component engineering and offers a feasible strategy for developing multifunctional polyimide foams with enhanced thermal stability and fire safety.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2026
·
IF 9.1
Yuchen Zhang,Xiaowei Zhou,ManMan Huo,Junfen Li,Yanfang Fan,Rong Zhang,Nanwen Li
Evaporation-rate control regulates kinetic trapping during polyimide membrane formation. • Stronger kinetic trapping preserves loosely packed nonequilibrium chain configurations with increased free volume. • Decarboxylative cross-linking amplifies structural gains, enhancing CO 2 permeability with modest selectivity loss. • This simple processing strategy improves CO 2 /CH 4 separation without polymer-backbone redesign or additional reagents. Kinetic trapping, the arrest of polymer chains in non-equilibrium configurations during rapid solvent evaporation, provides a deliberate route to engineer free-volume architecture in gas separation membranes. By controlling the solvent evaporation rate through casting temperature, faster evaporation from two solvents of contrasting volatility (DMAc and THF) systematically traps 6FDA-TFDB-DABA polyimide chains in more loosely packed configurations. This produces enlarged free volume, evidenced by expanded interchain spacing (5.33 to 5.49 Å, DMAc; 5.40 to 5.58 Å, THF), decreased density, enhanced birefringence, and increased surface roughness. This looser chain packing contributes to a substantial increase in CO₂ permeability, from 25.7 to 41.1 Barrer for DMAc-cast membranes and from 33.8 to 49.0 Barrer for THF-cast membranes, corresponding to increases of approximately 60% and 45%, respectively. These permeability gains arise from concurrent improvements in both CO₂ diffusivity and solubility, while the CO₂/CH₄ selectivity decreases only modestly. After thermal decarboxylation cross-linking at 340 °C, the rapidly evaporated THF-based membrane reaches 89.9 Barrer and surpasses the 1991 Robeson upper bound, withstanding feed pressures up to 600 psi without plasticization. This kinetic-trapping strategy requires no new reagents, monomer synthesis, or complex processing, offering a scalable, industrially compatible route to high-performance polyimide gas-separation membranes. Download: Download high-res image (280KB) Download: Download full-size image
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高影响因子
Advanced Membranes
·
2026
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IF 12.6
Wensong Ma,Ligang Lin,Bingchen Yu,Hongchao Li,Jing Yang,Mengfan Hou,Qi Wang,Zining Guo,Zhize Yu
Achieving efficient and stable separation of complex dye/salt systems under ultra-low driving pressures is crucial for reducing energy consumption in membrane processes and advancing sustainable water treatment technologies. However, conventional membrane systems are still constrained by high transport resistance, interfacial instability, and severe fouling, which collectively hinder their long-term separation performance. Herein, inspired by natural capillary transport, we report a biomimetic PI–SiO 2 –TA@Fe composite membrane fabricated via a synergistic combination of solvent-induced phase separation and in situ coordination chemistry. The resulting sponge-like, hierarchically interconnected porous architecture, together with a functional hydrated interfacial layer, enables continuous low-resistance transport pathways and capillary-assisted water permeation under ultra-low pressures. Meanwhile, the stable hydration interface effectively suppresses fouling while maintaining high separation selectivity. Benefiting from these synergistic structural and interfacial regulations, the membrane exhibits a water flux of 110 L m -2 h -1 , high dye rejection (>98%), and low salt rejection. Remarkably, efficient separation can still be achieved under simple manual pressure without external pumping. This integrated strategy, combining capillary-assisted transport, hierarchical pore engineering, and interfacial hydration defense, establishes a biomimetic design paradigm for low cost, low energy, and high stability separation membranes. It demonstrates strong potential for industrial wastewater treatment, portable water purification, and sustainable desalination. Download: Download high-res image (230KB) Download: Download full-size image
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高影响因子
ACS Sensors
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2025
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IF 9.1
Luntao Xia,Wei Xiao,Luoxin Li,Xin Liu,Qibin Zhuang,Yong Huang,Tianhao Lan,Xiaohui Du,Yang Zhao,Dezhi Wu
Flexible capacitive pressure sensors are now widely used in the fields of electronic skin, medical monitoring, and human–computer interaction. However, most of the current flexible capacitive pressure sensors generally suffer easy saturation and low sensitivity under high pressure. This paper proposes a new strategy using evenly distributed spiked nickel (Ni) particles as fillers in a nanofiber membrane to prepare flexible capacitive pressure sensors. The spiked Ni particles are embedded into the interior of polyimide (PI) electrospun nanofiber membranes by electrostatic self-assembly. The experimental results show that the introduction of spiked Ni particles effectively increased the sensitivity of the sensor under high pressure due to the formation of many parallel microcapacitors. In addition, a novel combination method is adopted to integrate individual sensor modules into arbitrary sensor arrays for sensing field pressures. Specifically, the sensor prototype with a 2.7 weight ratio of spiked nickel/PI nanofiber membranes was characterized by short response/recovery times (30/40 ms), wide pressure detection range (1.5 MPa), and excellent mechanical stability (1000 cycles), more than 4-fold increase in sensor sensitivity (4.04 MPa–1 at 0–1.5 MPa) compared to pure PI nanofiber membrane dielectric layers. Due to its superior performance demonstration, the sensor could be applied in many scenarios, such as human motion detection, sleeping posture monitoring, and plantar pressure measurement, indicating good application prospects in diverse wearable systems.
研究领域:
传感器技术
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纳米材料
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柔性电子器件
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PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
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2025
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IF 6.6
Suhang Hou,Libo Wang,Lina Huang,Bo Wang,Weiwei Zhang,Jian Xie,Yihang Feng,Xinxin Cao,Aiguo Zhou
Polyimide (PI) is well known for its excellent thermal stability and mechanical strength, but its limited thermal conductivity and tribological performance restrict broader applications under harsh conditions. In this work, Ti 3 C 2 T x MXene nanosheets were incorporated into a PI matrix via in-situ polymerization to fabricate high-performance Ti 3 C 2 T x /PI nanocomposites with uniform filler dispersion. The thermal conductivity of the composite reached 1.99 W m −1 K −1 at 20 wt% MXene loading—an increase of 123% over pure PI. The thermal degradation temperature at 10% weight loss (T d10 ) also improved from 577.6 °C to 587.0 °C. Additionally, both storage modulus (E s ) and glass transition temperature (T g ) increased, indicating improved rigidity and thermal resistance. Tribological tests at room temperature and 200 °C revealed that the addition of 5 wt% MXene effectively reduced the coefficient of friction (COF) by 6.52% and 5.37%, respectively. The wear rate was also significantly reduced—by 83.41% at room temperature and 39.66% at 200 °C. These enhancements are attributed to the formation of a continuous and robust transfer film composed of MXene, oxides, and friction-induced organic products. This work provides a promising route for high-performance PI-based composites with improved thermal and tribological functionalities.
研究领域:
材料科学
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热管理
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摩擦学
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高影响因子
ACS Applied Materials & Interfaces
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2025
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IF 8.2
Long Ni,Cuiqing Zhou,Lu Shen,Ke Yang,Yinfu Luo,Liwei Yan,Shuang Xia,Mei Liang,Shengtai Zhou,Huawei Zou
Lightweight porous materials with integrated cushioning and shock absorption, excellent thermal insulation, and hydrophobicity demonstrate a broad application prospect in high-end engineering sectors. Herein, the fabrication of lightweight polyimide foams (PIFs) containing trifluoromethyl and siloxane moieties was proposed by adopting copolymerization and microwave-assisted foaming processes. The synthesis and preparation of fluorine- and silicon-containing polyester ammonium salt (PEAS) precursor powders and subsequent PIFs, as well as the relationship and mechanism between structure and properties, were systematically explored. The construction of the anisotropic pore structure was attributed to the “bottom-up” directional foaming behavior of the microwave-assisted foaming process, which endowed PIFs with different traits with respect to the pore growth direction. The resulting copolymerized PIFs displayed low density (18.3–27.7 kg/m3), enhanced mechanical flexibility (compressive strength improvement of 26.2%, compression response rate between 97.5 and 99.1%), excellent thermal stability (T5% > 485.2 °C), and thermal insulation performance. Combining the micro/nano pore structure with the presence of hydrophobic trifluoromethyl and siloxane moieties, PIFs exhibited exceptional hydrophobicity with the water contact angle, reaching as high as 145.9° in the vertical direction (parallel to pore growth direction) and 136.3° in the horizontal direction (perpendicular to pore growth direction). Therefore, lightweight, mechanically flexible, thermally insulating, and hydrophobic PIFs were successfully prepared by the proposed approach, which demonstrate potential applications in the aerospace, transportation, microelectronics, and nuclear energy sectors, among others.
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
APPLIED SURFACE SCIENCE
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2025
·
IF 6.9
Jiahao Hu,Chang-Heng Li,Yingfan Zhang,Zhengyong Huang,Zhou Sha,Jian Li
Triboelectric nanogenerators (TENGs) hold great promise for micro/nano-energy harvesting and self-powered electronics, yet their development is hindered by the intrinsic trade-off between wear resistance and triboelectric performance. Materials with excellent triboelectric properties often exhibit poor wear resistance, creating a fundamental trade-off between high power output and mechanical durability. Herein, this study introduces composite fluorination to synergistically enhance both wear resistance and triboelectric performance in polyimide films. We fabricated both thermally cured and UV-cured fluorinated polyimide films, systematically investigating the effects of composite fluorination on the comprehensive material properties and wear resistance characteristics of polyimide. Furthermore, we elucidated the underlying mechanism responsible for the enhanced triboelectric performance in composite fluorinated polyimide films, with specific emphasis on analyzing charge transfer behavior variations before and after polarization. Compared to pristine polyimide, the fluorinated composite sample exhibited a markedly lower coefficient of friction of 0.04, which corresponds to a reduction of 89.5 %. Meanwhile, its surface charge density increased by 77.3 %, from 71.5 µC·m −2 to 126.8 µC·m −2 . This work presents a viable strategy for co-optimizing wear resistance and triboelectric performance in triboelectric materials, thereby enabling their practical implementation in sustainable energy harvesting systems while accelerating the development of high-performance triboelectric materials and advanced TENG devices.
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高影响因子
Journal of Environmental Chemical Engineering
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2025
·Vol. 14
·期 1
·120850
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IF 7.2
Xiaohua Tong,Enyang Zhang,Guangran Shao,Ming Yuan,Boyi Song,Wangqing Zhang
Polymer blending is a simple and cost-effective method to improve the gas separation performance of polyimide membranes, thereby potentially overcoming the inherent permeability/selectivity trade-off effect. However, its application still faces challenges, since only a few polymers are miscible with polyimides, and the mechanical property of the membranes usually reduces significantly after polymer blending. Herein, we prepare membranes by blending polyimide containing bulky isopropyl substituents with a small amount of polar polymers such as polyacrylonitrile (PAN). The resultant blend membranes using PAN as additive not only possess excellent gas separation performance but also maintain good mechanical property. For example, when 0.8 wt% PAN is added, the corresponding blend membrane displays a high CO 2 permeability of 632.2 Barrer and a high CO 2 /CH 4 selectivity of 23.4 under humidified condition, close to the 2008 Robeson upper bound, which is attributed to the formation of micro-phase separation structure within the blend membranes. Moreover, the tensile strength of the blend membranes using 0.8 wt% PAN as additive is only 12 % lower than that of the pure polyimide membrane. In addition, the blend membranes using PAN as additive show remarkable stability against physical aging and outstanding long-term operation stability, suggesting their great prospect for natural gas purification and biogas upgrading.
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高影响因子
JOURNAL OF POLYMER SCIENCE
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2025
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IF 3.6
Panpan Zhang,Ke Zhang,Ting Du,Shuliang Dou,Jiupeng Zhao,Yao Li
The high dielectric constant inherent to traditional polyimides (PIs) limits their ability to meet the demands of high-frequency circuit boards. The challenge of reducing this dielectric constant, while simultaneously preserving or enhancing the material's overall performance, is of critical theoretical and practical significance for advancing the use of PIs in the 5G communication sector. In this study, fluorinated graphene/polyimide (FG/PI) was employed as a reinforcing layer to fabricate a double-layer structure that enhances the mechanical and breakdown properties of low-dielectric PIs. PI porous composite films were developed using a layer-by-layer coating method, and their dielectric, mechanical, and thermal properties were investigated. The resulting double-layer PI films exhibited low dielectric constants and robust comprehensive performance. Specifically, the dielectric constants of the three films, PI-1, PI-2, and PI-3, were 2.01, 1.90, and 1.70, respectively, with corresponding tensile strengths of 42.69 MPa, 37.54 MPa, and 24.41 MPa, and breakdown strengths of 180.75 kV mm −1 , 138.70 kV mm −1 , and 89.77 kV mm −1 . These results underscore the importance of multi-layer structural designs in enhancing the breakdown resistance and mechanical properties of porous films, which are critical for the practical application of low-dielectric porous PI materials. Graphical The preparation process and properties of double-layer polyimide films.
研究领域:
材料科学
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电气工程
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高分子复合材料
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纳米技术
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通信技术
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DOI
高影响因子
Advanced Membranes
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2025
·
IF 9.5
Lixin Xing,Mengshi Wei,Jiaming Wang,Shiqi Huang,Wenji Zheng,Xiaobin Jiang,Shouhai Zhang,Gaohong He,Xuehua Ruan
Polyimide materials with multiple trifluoromethyl groups in repeating units, e.g., 6FDA-TFMB, have excellent intrinsic performance for membrane-based helium enrichment. Nevertheless, these fluorinated groups would seriously weaken cohesive energy density and then decelerate molecular chain aggregation in supersaturated solution. For asymmetric membrane fabrication using dry-wet phase inversion technology, this variation is negative to form dense and selective skin layer during solvent evaporation. In this research, EtOH, because it possesses low boiling point and little effect on solution stability, is utilized to enhance surface evaporation and accelerate polymer inspissation locally to construct defect-free skin layer. Meanwhile, formamide, because it could simultaneously motivate gelation and increase viscosity for polymer solution, is used to speed solidification during nonsolvent induced phase inversion, so that the transitional layer next to the surface could be formed instantaneously with artful sponge structure to consolidate and protect the nascent dense layer. The membrane casting solution is optimized with 22.0 wt% 6FDA-TFMB, 30.0 wt% EtOH, 3.0 wt% formamide, 31.5 wt% NMP, and 13.5 wt% THF, approximately. The defect-free dense layer could be thinner than 150 nm through this favorable formula. Besides, helium permeance is tested to be 760 GPU, the selectivity between helium and methane is tested to be 157, and the allowable operation pressure is higher than 4.0 MPaG, respectively. After adequate aging treatment, helium permeance is stabilized at 398 GPU, and the selectivity is increased to 239.5. On the whole, this work supplied an effective strategy to overcome the weakness in low cohesive energy density and construct highly fluorinated polyimide materials into excellent membranes with ultrathin and defect-free selective layer.
研究领域:
膜科学
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高分子科学
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分离技术
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材料工程
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化学工程
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高影响因子
JOURNAL OF POLYMER RESEARCH
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2025
·Vol. 32
·期 7
·1-8
·
IF 2.8
Liu Huiping,Sui Luyu,Luo Shilei,Wang Zixin,Xu Meng,Zhong Ming,Hou Haoqing,Peng Xinwen
Polyimide (PI) is very popular in polymer film capacitors due to its excellent performance and easy film-forming properties. However, its relatively low dielectric constant (approximately 3–4) limits its application and development in the field of high-performance capacitors. In general, dielectric constant can be enhanced effectively by adding special filler materials into polyimide. In this study, core–shell structured C@SiC nanoparticles were synthesized via a hydrothermal method. Novel polyimide composites (C@SiC/PI) were obtained by dispersing C@SiC nanoparticles into polyamic acid, followed by thermal imidization. The dielectric constant of C@SiC/PI composite material is as high as 40.2, which is 11.4 times that of pure PI. The maximal discharging energy density reached up to 2.49 J cm −3 with 10% C@SiC nanoparticles, which is almost 3 times higher than pure PI under identical conditions. Additionally, the composites have excellent thermal stability with a decomposition temperature of 5% above 530℃. The tensile strength of the composite film is in the range of 89.7–130.50 MPa, and the elongation at break is between 5.4% and 9.1%, maintaining good mechanical properties. Consequently, the fabricated composites hold significant promise for applications in polymer thin-film capacitors and flexible electronics.
研究领域:
材料科学
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电气工程
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纳米技术
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yunting Hu,Jiandong Hu,Yongliang Zhao,Xiaomin Zhu,Haitao Wang
Polyimide (PI) composite films incorporating silica hollow nanoparticles (SHN) were successfully fabricated, exhibiting a distinct asymmetric structure. The surface morphology, composition, optical properties, and mechanical performance of the films were systematically investigated. Scanning electron microscopy and atomic force microscopy confirmed the preferential segregation of SHN toward the top surface, attributed to their low density and high surface activity. This led to a rougher top surface with a higher SHN concentration, while the bottom surface remained relatively smooth with a dominant PI phase. Optical measurements revealed a significant reduction in reflectance, particularly on the rough top surface, while maintaining high transmittance. Mechanical analysis, including tensile testing and nanoindentation, demonstrated that SHN incorporation enhanced the elastic modulus and hardness of the films, with the bottom surface exhibiting superior mechanical properties due to the compact stacking of PI and SHN. These findings provide valuable insights into the structural design of antireflective PI composite films and underscore the critical role of hollow nanoparticle surface activity in determining film morphology and functionality.
研究领域:
材料科学
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纳米技术
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光学材料
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聚合物复合材料
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高影响因子
危险品化学品经营许可证（带存储）