CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xinbin Ji,Yulong Xiang,Jing Guo,Fucheng Guan,Xiaoqing Xiong,Da Bao,Qiang Yang,Minghan Li,Yihang Zhang,Zheng Li,Jianbin Sun
In response to the demand for safety protective textiles suitable for extreme conditions such as intense heat and humidity, we have innovatively developed a novel approach using polyacrylonitrile (PAN) in-situ reinforced polyimide (PI) superhydrophobic porous fibers. We blended fluorinated polyamic acid (PAA) with PAN and prepared PI/pre-oxidized fiber (panof) porous fibers using a process that includes wet phase separation spinning and integrated synchronous imidization/pre-oxidation. Special emphasis was placed on the chemical mechanisms during the heat treatment stage of the preparation process. The uncapped PAA underwent imidization reactions and also facilitated PAN’s pre-oxidation, which notably enhanced the structural stability of the PI porous fibers. This novel enhancement mechanism effectively addresses the challenges of structural collapse and volume shrinkage encountered in the preparation of traditional PI porous fibers. In addition, our investigation into the impact of thermal imidization temperature on the structure of porous fibers led to the evaluation of PI/panof porous fibers. The PI/panof-320 porous fibers, produced by the combined enhancement effect of fluorinated PI and PAN, showcased exceptional features: superhydrophobicity (water contact angle = 168.9°), low density (0.078 g/cm 3 ), reduced thermal conductivity (0.0251 W/(m·K)), high strength (22.18 MPa), outstanding flexibility (bend radius = 205 μm), and superior flame retardancy and insulation. The outstanding performance of these composite porous fibers paves the way for innovative, comfortable, and safe wearable devices in high heat and humidity environments, highlighting their extensive applicability and potential.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Haiyang Dai,Yang Zhang,Yang Yang,Jing Chen,Chongyang Li,Hao Liu,Wentao Liu,Xin Li,Tingting Zhang,Renzhong Xue,Tao Li
Three kinds of polyimide (PI) films with low dielectric constant and excellent comprehensive properties were prepared by polycondensation reaction employing 6FDA as the dianhydride monomer and 6FODA, TFMB and 6FDAM as the diamine monomers, respectively. The effects of diamine moieties on the low dielectric constant and comprehensive properties were investigated by experiments and theoretical simulations. All three PI films show excellent high temperature resistance. For instance, the 5 % weight loss temperature ranges from 495 to 511 °C, and the T g from 305.5 to 347.2 °C. 6FDA/6FODA exhibits a higher dielectric constant ( k ) compared with the other two PIs because of low free volume fraction and low rotating energy barrier of torsion angle for 6FODA moieties. 6FDA/TFMB exhibits ultra-low k (1.84 at 10 4 Hz) being benefit from its high free volume fraction caused by the strong rigidity of molecular chain. Despite having the highest free volume fraction among the three PIs, 6FDA/6FDAM exhibits a slightly higher dielectric constant than 6FDA/TMFB due to the fact that the torsion angle for 6FDAM moieties has low rotating energy barrier, which is beneficial for improving the molecular polarizability. Meanwhile, all the PI films show excellent transparency in the visible light range as well as excellent mechanical properties. The results indicate that the microstructure of PI can be effectively adjusted, thus achieving an ultra-low k and excellent comprehensive properties by rationally designed diamine moiety.
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高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xinfu Zhao,Mengqing Su,Shimo Yu,Jing Zhang,Xiaochan Liu,Kang Qiu,Xibin Yi,Jian Zhang,Guoliang Dou,Mengdi Wang
Polyimide (PI) aerogel is a good thermal insulation material with the highest temperature resistance in practical application. But the mechanical strength of PI aerogels prepared by freeze-drying or thermoimide methods is weak. In this research, TPU was selected as an aging solution to solve the problem of the low mechanical strength of PI aerogel prepared by the freeze-drying method. Previous work has certified that the coupling of PI and thermoplastic polyurethane (TPU) can enhance the mechanical strength of PI aerogel to a certain extent due to the flexibility of TPU. But excessive TPU will change the PI structure in the cross-linking process and decrease the mechanical strength of the aerogel. Thus, a new kind of PI gel modification method was provided by using TPU as an aging solution, and the mechanical strength of PI aerogel is improved to 3.06 MPa. Furthermore, the shrinkage, specific surface area, waterproof angle, and thermal conductivity all show good performance, thus enabling PI aerogel to be used in many aspects. Specially, the method is simple and can be used to prepare some other high-strength aerogels.
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Nan Zhou,Zicheng Fan,Insub Noh,Yanbin Wang,Bin Li,Hyung Do Kim,Baolin Xiao,Qi Zhou,Hideo Ohkita,Biaobing Wang
In this study, an efficient interfacial solar steam generation (ISSG) system has been designed from the viewpoints of molecular design and crystallization kinetics, and fabricated to produce clean water and remove various hazardous substances. With incorporating of polar side unit (–COOH) into PI molecule, the composite aerogel offered sufficient water transporting capacity through capillary force compared to composite aerogel with inert side unit (–CH 3 ), although the same hybrid photo-thermal materials (carbon fiber and polyaniline) were adopted. Meanwhile, by controlling the freezing rate and ice crystal growth, the porosity increased from 63.2 % to 89.9 %, and pore size decreased from 150 to 60 μm, which provided much more photo-thermal interfacial area to evaporate water molecules. As a result, a new record of evaporation rate of 5.17 kg m -2 h −1 has been achieved for ISSG system based on PI aerogel irradiated by xenon light with an intensity of 1000 W m −2 , which is far higher than that of ISSG system based on –CH 3 composite aerogel (0.62 kg m -2 h −1 ). Excitingly, the designed composite aerogel also shows excellent capacity to adsorb various heavy metal ions (83.3 mg g −1 for Cu 2+ , 79.8 mg g −1 for Ni 2+ and 68.8 mg g −1 for Cr 6+ ) and outstanding removal efficiency of organic dyes (approaching to 100 %) with the help of synergistic effect of electrostatic adsorption, hydrogen bonding interaction, metal–ligand coordination, chelation effect and redox. More importantly, this ISSG system possesses long-term stability, the evaporation rate is nearly unchanged even it has been treated for 100 h under 1 kW m −2 irradiation owing to the robust morphology and durability of polar group. As a typical case, the PI composite aerogel possesses a good thermal insulation in a broad temperature range from −25 to 200 °C and excellent flame retardancy. Overall, this work provides a prospective strategy to construct highly efficient clean water generation system with versatile and stable performances for practical application.
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高影响因子
POLYMER
·
2025
·
IF 4.5
Xiuyuan Wei,Chao Shan,Zhongying Liu,Zhiqing Liang,Hui Wu,Chanjuan Liu,Xiaohua Huang
A novel sulfur-and fluorine-containing dianhydride monomer 2,2-bis[4-(3,4-dicarboxyphenylthio)phenyl]hexafluoropropane dianhydride (6FDAPSA) was synthesized by molecular design, and a series of random co-polyimides were prepared from 6FDAPSA, 4,4-(hexafluoroisopropene)diphthalic anhydride (6FDA) and 4-(3-fluoro-4-(trifluoromethyl)phenyl)-2,6-bis(4-aminophenyl)pyridine (FTPPA). The obtained co-polyimides exhibited excellent thermal properties ( T g > 288 °C, T 5 % > 504 °C, T 10 % > 536 °C), good optical properties (λ cut-off > 342 nm, λ 80 % > 410 nm), commendable mechanical properties (tensile strength >75 MPa) and outstanding hydrophobic properties (contact angle >90.0°). They also showed excellent solubility in both high and low boiling point organic solvents. Besides, Wide-angle X-ray diffraction test and molecular simulation confirmed that the prepared co-polyimides possess a large molecular chain spacing, with d-spacing values ranging from 5.59 to 5.84 Å and fractional free volume from 0.237 to 0.280. Consequently, polyimide membranes exhibited commendable gas permeability values of He (up to 49.5 barrer) and CO 2 (up to 34.2 barrer), and good ideal gas selectivity values of He/N 2 (up to 34.2) and CO 2 /N 2 (up to 22.2). These results indicate that polyimide matrix materials have potential application prospects in the field of gas separation.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Rashida Shahbaz,Tianyou Li,Yongchao Sun,Samrina Sharif,Gaohong He,Canghai Ma
Mixed matrix membranes (MMMs) have emerged as promising materials for hydrogen separation, combining the processability of polymers with enhanced permeability and selectivity offered by inorganic fillers. However, challenges such as filler aggregation and poor polymer-filler interfacial compatibility limit their performance. In this study, amino-modified bimetallic ZIF (Zn/Co-ZIF-NH 2 ) was synthesized and employed as a novel nanofiller to fabricate 6FDA-DAM-based MMMs, aiming to improve interfacial compatibility between the filler and the polymer matrix. The incorporation of Co 2+ ions into ZIF-8-NH 2 introduced a synergistic effect, optimizing the balance between the rigidity and flexibility of metal-to-ligand bond linkage, while amino groups promoted robust interfacial interactions with the polymer matrix. Compared to the pure polymeric membrane, the MMMs incorporating 40 wt% MOF exhibited a significant enhancement in gas permeability, with H 2 permeability rising from 750 to 3273 Barrer and CO 2 permeability increasing from 840 to 2733 Barrer, corresponding to improvements of 336.4 % and 225 %, respectively. Simultaneously, H 2 /CH 4 and CO 2 /CH 4 selectivities increased to 33.7 and 28.1, representing improvements of 88.3 % and 41 % over the pristine polymer. These performance metrics exceed the 2008 Robeson upper bounds, demonstrating the effectiveness of Zn/Co-ZIF-NH 2 nanofillers in overcoming the permeability–selectivity trade-off. This study underscores the effectiveness of amino-modified bimetallic MOFs as advanced fillers for high-performance MMMs, particularly suited for hydrogen purification and CO 2 separation applications.
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高影响因子
POLYMER
·
2025
·
IF 4.5
Shijie Liu,Long Ni,Yuanyu Chang,Hexing Sun,Shuang Xia,Mei Liang,Huawei Zou,Shengtai Zhou
In this work, lightweight, thermal insulative and hydrophobic polyimide foams (PIFs) with anisotropic pore structure were fabricated. Polyester ammonium salt (PEAS) precursor powders were synthesized by adopting copolymerization strategy where ODA was used as diamine and different molar ratios of BTDA/BPADA was used dianhydride. Afterwards, PIFs were prepared by microwave-assisted foaming and thermal imidization treatment. The “bottom-up” directional foaming process led to the formation of regular near-spherical pores in the vertical direction and well-arranged ellipsoidal strip-like pores in horizontal direction (perpendicular to the pore growth direction), thereby endowing PIFs with anisotropic mechanical, thermal insulation and hydrophobic properties. The compressive strength in the vertical direction was 1-3 times higher than that in horizontal direction. The aligned ellipsoidal strip-like pore structure in the horizontal direction endowed PIFs with low thermal conductivity (0.0267 W/(m·K)) which is quite comparable to that of air. Moreover, the water contact angel of PIFs in the vertical direction reached as high as 128.0°, displaying exceptional hydrophobicity. This work provided a facile method to fabricate multifunctional PIFs that show a promising application in the aerospace, construction, energy and nuclear energy sectors among others.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Dan Qiu,Yanping Zhang,Zishun Xu,Qing Fang,Jiaqin Cao,Xiuxiu Mu,Fan Hu,Hongxing Liu,Chuner Lin,Linghui Wang
Organic solvent nanofiltration (OSN) has emerged as a promising separation technology for product purification and solvent recycling in organic solution. Crosslinked polyimide (PI) membranes were widely used in the OSN system. However, the existence of some drawbacks, such as low utilization of crosslinkers and generation of profuse organic waste, hindered the development. Furthermore, when crosslinkers of large molecular weight were applied, the crosslinking degree of membranes was usually found to be insufficient, restricting their performance in harsh solvent systems. In this work, PEI with specific protonation degree, performing as a crosslinker, was directly introduced into PI solution for the preparation of OSN membranes. The partially activated PEI would graft onto PI chains, which could improve the retention of PEI chains during the membrane forming process, while preventing the gelation of PI solution. The as-prepared PEI/PI membrane showed enhanced hydrophilicity and highly positive charge with the isoelectric point as high as 9.1. The PEI/PI membranes were post-treated by K 2 CO 3 solution, aiming to further improve the crosslinking degree. The PEI/PI membranes exhibited good organic solvent resistance even in N, N-dimethylformamide (DMF), with the tensile strength of 0.28 MPa and permeance of 2.38 L m −2 h −1 bar −1 . Meanwhile, the dye/salt separation performance of the membrane was carried out by using DMF/H 2 O (1:9 w/w) as the solvent, and the rejection for several dyes was above 97 %, with the rejection for salts below 8 %. After 80 h test, the membrane maintained high rejection for Congo Red and Methyl Blue and low rejection for salt, with the permeation retained at 20 L m −2 h −1 bar −1 , indicating excellent anti-fouling performance. The controlled activation method takes the advantage of high utilization and reaction efficiency, as well as simple procedure, rendering it valuable for fabrication of OSN membranes.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yu He,Qili Zhou,Wen Wang,Zitan Yang,Zhi Liang,Zhangcheng Li,Honghao Cao,Chong Hou
Polyimide (PI) foams possess excellent mechanical properties and high-temperature resistance, which present significant utility in the aerospace, transportation, and microelectronics industries. The microstructure of PI foam, specifically the pore size and porosity, significantly influences its physical and mechanical properties. However, achieving both high porosity and small pore size simultaneously is greatly challenging for PI foams, especially via the foaming method. Here, we report PI foams with mean pore size of 98.1 μm and porosity of 92 % using a one-step scrape foaming method. The scraping thickness is found to be key to adjusting the pore size of the foam due to the interface effect in the initial stage, and maintaining optimal air pressure and low temperature allows slow bubble growth without bursting or merging, resulting in PI foams with high porosity and small pore size. The PI foam we fabricated exhibits excellent thermal insulating performance, with a low thermal conductivity of 20 mW/m∙K. The scrape foaming method provides an efficient and low-cost strategy for the preparation of PI foams with a tunable porous structure and is expected to find a variety of applications in thermal insulation and environmental protection.
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高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Xiaoke Wei,Feng Wang,Daxiong Wu,Canying Zhang,Haitao Zhu
Radiative cooling materials have attracted extensive research interest due to their unique characteristics of zero energy consumption and minimized carbon footprint. However, the design and manufacture of radiative cooling materials for outdoor electronic devices remain to explore. In this study, a silica/fluorinated polyimide fiber film was particularly designed and fabricated for the radiative cooling of outdoor electronic devices. The film was prepared by an electrospinning-electrospray process with hexafluoroisopropylidene, diaminobiphenyl, and silica as raw materials. Composed of polyimide nanomicrometer fibers and polyimide-silica bead-like particles, the prepared film delivered an average solar reflectivity of 94.29% and an average mid infrared emissivity of 93.12%. Especially, the film exhibited high emissivity in the band of 6–16 μm, where the emission of electronic devices is relatively concentrated. Under direct sunlight, the radiative cooling film achieved a temperature 30.6 and 9.4 °C cooler than the commercial polyimide films and commercial high reflective coatings, respectively. The film also cooled a smartphone in high load operation under sunlight by 3.6–4.1 °C. The findings of this work provide new insight into the research and development of radiative cooling materials for outdoor electronic devices.
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PubMed
高影响因子
POLYMER
·
2024
·
IF 4.1
Songhao Mo,Hong Ruan,Yuqi Li
Triboelectric nanogenerators (TENGs) are eco-friendly energy harvesters. Polyimide (PI) has been widely used as a triboelectric layer in TENGs, but the relationship between its structure and performance is not fully understood. Herein, PI films with varying molecular structures were prepared to investigate the effects of -O- and –CF 3 groups on their physical properties and triboelectric performance. The results showed that PI films with -O- exhibited better thermal stability, while both -O- and –CF 3 groups effectively modulated optical transparency and dielectric properties. At 450 nm, M6-PI and O6-PI exhibited the highest transmittance at 63.14 % and 55.06 %, respectively, with dielectric loss performance below 0.5 % at 10 5 Hz. PI films incorporating -O- and –CF 3 demonstrated significant improvements in triboelectric performance. Theoretical calculations clarified these groups influence optical transparency, dielectric properties, and electrical output performance. Ultimately, the fabricated 6PI-TENG achieved the desired triboelectric performance with enhanced electrical output. The V oc and Q sc of 6PI reached approximately 80 V and 25 nC, respectively. This study offers essential theoretical insights for designing and advancing of TENGs, contributing to sustainable energy development.
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高影响因子
JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 10
·1-11
·
IF 2.6
Guo Yawen,Yang Li,Lv Chengcheng,Mai Chongyang,Zhao Lielun,Jiang Yan,Zhang Hongwen
Inspired by nepenthes pitcher plants, the slippery liquid-infused porous surfaces have received extensive attention. In its practical application, good oil storage and oil-locking ability are important guarantee for the surface to maintain the interface performance for a long time. In this paper, mesoporous silica (KCC-1) was obtained by cetyltrimethylammonium bromide (CTAB) as template agent, urea as a hydrolyzing agent, and TEOS as silicon source reagent, then modified with (3-Aminopropyl) trimethoxysilane. Then combined with the breath figures, amino-modified mesoporous silica, 3,3’-4,4’-biphenyltetracarboxylic dianhydride (S-BPDA), 2,2’-bis[4-( 4-aminophenoxyphenyl)]propane (BAPP) were used as raw materials to prepare polyimide SLIPS with good stability by a two-step method. The wettability and stability of SLIPS were investigated, and the results show that the introduction of mesoporous silica inorganic nanoparticles enhanced the performance of SLIPS. Among them, the sliding angle of polyimide SLIPS with a nanoparticle content of 10% is 2°, which has good self-cleaning performance, antifouling performance, and stability.
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高影响因子
危险品化学品经营许可证（带存储）