查找使用阿拉丁产品的科研文献

Effect of Anti-Hydrolysis AlN Microspheres on the Electrical Insulation and Thermal Conductivity of PMIA Paper

Fangcheng Lü,Rui Yang,Haoou Ruan,Shenghui Wang,Xiang Yu

Robust Hydrophobic PMIA Nanopaper with Enhanced Flashover Resistance via Plasma and Nano-SiO2 Co-modification

Xiang Yu,Yi Ru,Guangjia Mu,Xinwei Zhang,Kaixuan Sun,Rui Yang,Sidi Fan

Poly(m-phenylene isophthalamide) (PMIA) nanopaper exhibits remarkable thermal stability, excellent electrical insulation properties, and high mechanical strength, making it broad application prospects in high-voltage power systems. Nevertheless, its inherent hydrophilicity derived from amide groups facilitates moisture adsorption, leading to reduced insulation properties under humid conditions. This study presents a synergistic surface modification strategy integrating plasma modification and nano-SiO₂ coating to concurrently enhance the hydrophobicity, anti-icing performance, and electrical insulating properties of PMIA nanopaper. The modification procedure involves initial CF₄ plasma treatment for 120 s. Subsequently, a suspension of 2 wt% nano-SiO₂ is sprayed to form a composite coating. As a result, the sample exhibits superhydrophobic characteristics with a water contact angle of 158° and a sliding angle below 1°. The anti-icing performance is significantly improved, with water droplet freezing delayed beyond 600 s. Additionally, the surface flashover voltage increased to 17.16 kV, while the volume conductivity is as low as 1.18 × 10^-15 S/m. The increased density of shallow traps on the surface promoted charge dissipation and electric field homogenization.

Superhydrophilic ZIF-8@PMIA Nanofibrous Membrane With Demulsification Property for Efficient Separation of Oil-in-Water Emulsions

Zhibo Huang,Tiandi Pan,Haoxuan Mai,Ning Tang,Fei Sun,Peijian Du,Ni Li

Nanofibrous membranes have great potential for treating oily wastewater. However, the random stacking of nanofibers during the electrospinning process resulted in a broad pore size distribution and reduced separation efficiency. Moreover, for oil-in-water emulsions stabilized by ionic surfactants, the small oil droplets deform under the applied pressure and are squeezed into the membrane pores, leading to a decrease in flux and fouling. In this work, we developed superhydrophilic nanofibrous membranes with demulsification properties via electrospinning and a solvothermal seed-induced method. Notably, the incorporation of ZIF-8 nanoparticles offers multiple advantages, such as reducing membrane pore size, increasing the surface roughness, and enhancing membrane surface charge. These features synergistically improve both separation selectivity and demulsification properties. As a result, the membrane exhibits outstanding separation performance, achieving a separation efficiency of 96.37% for diesel-in-water emulsions and a high permeation flux of 4100 L m −2 h −1 for dichloromethane-in-water systems. This work provides an effective strategy for developing high-performance membranes for oil-in-water emulsions separation applications.

Nanoporous PVDF-HFP/PMIA Membrane with Heat-Resistance towards the Gel Polymer Electrolyte of Lithium Metal Batteries

Xiaoxue Liao,Wenxi Hu,Jiaqing Su,Sha Cheng,Cheng Huang,Shihan Hu,Zhuowei Wang,Xiao Chen,Chunxia Zhao,Pengchao Zhang

Developing gel polymer electrolytes (GPEs) is a promising strategy to mitigate safety concerns caused by the leakage of liquid electrolytes in lithium metal batteries (LMBs). However, fabricating a membrane with high thermal stability, whose derived GPE also maintains good electrochemical performance, remains a major challenge. Herein, we report a composite membrane, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/poly(m-phenylene isophthalamide) (PMIA), with excellent thermal stability and uniform nanoporous structure for high-performance GPE of LMBs. The PVDF-HFP/PMIA composite membrane, featuring a uniform pore size of 110 nm, is prepared by a double-sided solvent–nonsolvent exchange process via microfluidic technique. The incorporation of PMIA achieves the enhanced heat resistance of the composite membrane with a superior size retention of 86% after continuous heating at 250 °C for more than 360 min. The PVDF-HFP/PMIA GPEs-based Li||Li symmetric cells display stable voltage across various current densities and cycles for 600 h at 0.5 mA cm–2. Moreover, the morphology of the lithium anodes after 100 h shows uniform lithium deposition, demonstrating excellent suppression of lithium dendrite growth. The Li||LFP cells assembled with PVDF-HFP/PMIA-based GPEs deliver a high discharge capacity of 134.5 mAh g–1 at 5 C. The as-prepared heat-resistant GPEs membrane thus offers great potential for improving the safety performance of LMBs.

Sandwich-structured PVdF/PMIA/PVdF nanofibrous separators with robust mechanical strength and thermal stability for lithium ion batteries

Yunyun Zhai,Na Wang,Xue Mao,Yang Si,Jianyong Yu,Salem S. Al-Deyab,Mohamed El-Newehy,Bin Ding

Novel, sandwich-structured PVdF/PMIA/PVdF nanofibrous battery separators with robust mechanical strength and thermal stability are fabricated via a sequential electrospinning technique. The nanofibers of the PVdF and the PMIA layers are bonded and interconnected on the interface boundary without any polymer binder or post-treatment. Benefiting from the high porosity of the as-prepared membranes and the introduction of PMIA, the PVdF/PMIA/PVdF composite membranes exhibit high ionic conductivity (2.3 times higher than that of the Celgard membrane), robust tensile strength (13.96 MPa), and excellent thermal stability, sustaining insulation after closing the pores in the PVdF layer. Hot oven testing reveals that the composite membranes exhibit no dimension shrinkage after being exposed to 180 °C for 1 h. Furthermore, the as-prepared-membrane-based Li/LiCoO2 cell shows a higher capacity retention of 93.10% after 100 cycles and better rate performance compared with the cell using the Celgard membrane, providing new insight into the design and development of high-performance rechargeable lithium ion batteries.

A PDA@ZIF-8-Incorporated PMIA TFN-FO Membrane for Seawater Desalination: Improving Water Flux and Anti-Fouling Performance

Yu Ma,Rui Jia,Zhen-Liang Xu,Aida Aibulatova,Xiao-Gang Jin,Yin-Xin Fang,Ming-Xiao Zhang,Sun-Jie Xu

Forward osmosis (FO) technology, known for its minimal energy requirements, excellent resistance to fouling, and significant commercial potential, shows enormous promise in the development of sustainable technologies, especially with regard to seawater desalination and wastewater. In this study, we improved the performance of the FO membrane in terms of its mechanical strength and hydrophilic properties. Generally, the water flux ( J w ) of polyisophenylbenzamide (PMIA) thin-film composite (TFC)-FO membranes is still inadequate for industrial applications. Here, hydrophilic polydopamine (PDA)@ zeolitic imidazolate frameworks-8 (ZIF-8) nanomaterials and their integration into PMIA membranes using the interfacial polymerization (IP) method were investigated. The impact of PDA@ZIF-8 on membrane performance in both pressure-retarded osmosis (PRO) and forward osmosis (FO) modes was analyzed. The durability and fouling resistance of these membranes were evaluated over the long term. When the amount of ZIF-8@PDA incorporated in the membrane reached 0.05 wt% in the aqueous phase in the IP reaction, the J w values for the PRO mode and FO mode were 12.09 LMH and 11.10 LMH, respectively. The reverse salt flux ( J s )/J w values for both modes decreased from 0.75 and 0.80 to 0.33 and 0.35, respectively. At the same time, the PRO and FO modes’ properties were stable in a 15 h test. The incorporation of PDA@ZIF-8 facilitated the formation of water channels within the nanoparticle pores. Furthermore, the J s / J w ratio decreased significantly, and the FO membranes containing PDA@ZIF-8 exhibited high flux recovery rates and superior resistance to membrane fouling. Therefore, PDA@ZIF-8-modified FO membranes have the potential for use in industrial applications in seawater desalination.

Improving the thermal conductivity of PMIA/EP composites by the synergistic effect of modified boron nitride and graphene oxide

Yue Mengjie,Pu Zejun,Wu Fang,Zhu Rongli,Wang Xu,Yu Dayang,Zhong Jiachun

In this study, h-BN-OH was obtained by hydroxylating h-BN and subsequently KH560 was grafted onto the surface of h-BN-OH, resulting in h-BN-KH560. The h-BN-KH560 was then dispersed in an epoxy resin (EP) to create an EP/h-BN-KH560 adhesive solution, with the content of h-BN-KH560 being varied. Graphene oxide (GO) was dispersed in PMIA precipitated fibers to produce PMIA/GO composite paper. Finally, the surface of the composite paper was evenly coated with the EP/h-BN-KH560 adhesive solution, and then PMIA/EP/GO/h-BN composites with different h-BN-KH560 contents and good thermal conductivity were prepared by hot pressing. The FTIR analysis confirmed the successful grafting of KH560 onto the surface of h-BN-OH. By utilizing h-BN-KH560 and GO as thermal conductive fillers, we achieved a higher thermal conductivity in the composite material, creating a “dual thermal conductivity network” compared to using a single filler. Additionally, the thermal conductivity increased as the content of h-BN-KH560 increased. At h-BN-KH560 contents of 20 wt%, 40 wt%, and 60 wt%, the thermal conductivities of the prepared PMIA/EP/GO/h-BN composites were 0.661 Wm −1 K −1 , 1.082 Wm −1 K −1 , and 1.206 Wm −1 K −1 , respectively. Importantly, the addition of the thermal conductive filler did not significantly affect the thermal stability of the composites.

Improved thermal conductivity and dielectric properties of flexible PMIA composites with modified micro- and nano-sized hexagonal boron nitride

Duan Guangyu,Wang Yan,Yu Junrong,Zhu Jing,Hu Zuming

A series of flexible poly(m-phenylene isophthalamide) (PMIA)-based composites with different sizes and mass fractions of hexagonal boron nitride (hBN) were successfully manufactured for the first time via the casting technique. The effects of modified hBN particles on microstructure, mechanical properties, dielectric properties and thermal conductivities of fabricated composites were investigated. The results indicate that modified hBN particles manifest good compatibility with the PMIA matrix. The Young’s modulus and T heat-resistance index of PMIA-based composites are increased with increasing the mass fraction of hBN particles. Due to additional thermal conductive paths and networks formed by nano-sized hBN particles, the K-m/n-hBN-30 composite displays the thermal conductivity of 0.94 W·m -1 ·K -1 , higher than that of the K-m-hBN-30 composite (0.86 W·m -1 ·K -1 ), and more than 4 times higher than that of neat PMIA. Moreover, the obtained PMIA-based composites also show low dielectric constant and ideal dielectric loss. Owing to the excellent comprehensive performance, hBN/PMIA composites present potential applications in the broad field of electronic materials.

Superhydrophilic/underwater superoleophobic ZIF-8@PMIA nanofibrous membranes with hierarchical structure for the efficient separation of oil-in-water emulsion

Zhibo Huang,Tiandi Pan,Ning Tang,Fei Sun,Peijian Du,Ni Li

Nanofibrous membranes are considered ideal candidates for water purification. However, the membrane fouling results in an irreversible decline in separation flux, while the slippage of nanofibers leads to an increase in pore size under driving pressure, subsequently inducing a decline in separation efficiency. Rational structure design and material selection are crucial for separation performance improvement. In this study, we report double-layer hierarchical structured nanofibrous membranes that demonstrate simultaneous superhydrophilicity and underwater superoleophobicity for oil-water separation via a combination of electrospinning and seed-mediated solvothermal strategy. The double-layered hierarchical structure comprises an upper layer of ZIF-8@PMIA composite nanofibers and a bottom layer of PMIA nanofibers. Notably, the incorporation of ZIF-8 species confers several advantages, such as increased surface roughness, reduced pore size, and enhanced superhydrophilicity, collectively contributing to superior anti-fouling performance and high separation efficiency. Meanwhile, the bottom PMIA nanofibers, with larger diameters, ensure robust mechanical integrity for the entire membrane. Due to the rational structural design, the membrane achieves outstanding separation performance, including a 99.91 % separation efficiency for diesel-in-water emulsions and an ultrahigh flux of 3821.7 L m − 2 h −1 for dichloromethane-in-water emulsions. Therefore, this membrane has broad application prospects in the oil–water separation field.

Synergistic interaction of sulfonated poly(ether ether ketone) and carboxylated graphene oxide to enhance PMIA nanofiltration membrane performance for desalination

Mei Yang,Liang Zhao,Yuhao Zhang,Jinsen Gao

In this research, we prepared PMIA/GO-COOH/SPEEK composite nanofiltration membranes using a one-step phase inversion method. Firstly, carboxylated graphene oxide (GO-COOH) and sulfonated poly(ether ether ketone) (SPEEK) were prepared, and their synergistic interaction was used to modify PMIA nanofiltration membranes. Through cooperative interaction, the pore structure, surface hydrophilicity, and surface negative charge density of the PMIA/GO-COOH/SPEEK composite membrane were all enhanced. It is noteworthy that the membrane's water flux and desalination performance were enhanced significantly, thereby surmounting the trade-off between flux and rejection. The PMIA/GO-COOH/SPEEK (0.3 wt% GO-COOH, 1 wt% SPEEK) composite membrane exhibited a pure water flux of 154.3 (L/m 2 /h) at 0.8 MPa. Furthermore, it achieved a Na 2 SO 4 retention rate of 92.6%, marking a 20% enhancement compared to the retention rate of pure PMIA nanofiltration membranes, which was 75.2%. Moreover, the PMIA/GO-COOH/SPEEK composite membrane displays exceptional long-term stability, attributable to the covalent bond connection between the polymer and the modified materials.

Core–Shell PMIA@PVdF-HFP/Al2O3 Nanofiber Mats In Situ Coaxial Electrospun on LiFePO4 Electrode as Matrices for Gel Electrolytes

Lei Wang,Jiawei Yan,Ran Zhang,Yanfang Li,Wenzhuo Shen,Jiali Zhang,Min Zhong,Shouwu Guo

Gel electrolytes show certain advantages over conventional liquid and solid electrolytes, but their mechanical strength and surface adhesion to the electrode remain to be improved. To address the challenges, we design and fabricate herein the core–shell nanofiber mats in situ on the LiFePO4 electrode as matrices for gel electrolytes, in which the core is poly(m-phenylene isophthalamide) (PMIA) nanofiber and the shell are composite of Al2O3 nanoparticles and poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP). The mechanical property of the core–shell polymeric nanofiber mats and their surface interaction with LiFePO4 electrode are characterized complementarily using dynamic thermomechanical analysis and scanning electron microscopy. The electrochemical properties of the gel electrolytes based on the as-prepared matrices after being loaded with lithium salt solution are studied systematically on half coin cells. It is found that the ultimate strength of the core–shell PMIA@PVdF-HFP/Al2O3 mat can reach 6.70 MPa, 2 times higher than that of the PVdF-HFP/Al2O3 nanofiber mat. Meanwhile, the shell PVdF-HFP/Al2O3 can ensure manifest surface affinity to the LiFePO4 electrode and enhance lithium-ion conductance. Thus, the as-assembled LiFePO4 half coin cells using PMIA@PVdF-HFP/Al2O3 gel electrolyte show good electrochemical performances, especially the long cycle stability with the capacity retention of 96.6% after 600 cycles under 1C.

Polydopamine coated poly(m-phenylene isophthalamid) membrane as heat-tolerant separator for lithium-ion batteries

Pan Fusheng,Qiao Lina,Yuan Biao,Duan Cuijia,Wang Jianjie,Wu Wei,Lin Quanfan,Shi Yake,Chen Zan,Jiang Zhongyi

Poly(m-phenylene isophthalamide) (PMIA) membranes are promising heat-tolerant separator candidates of lithium-ion batteries (LIBs), while their wettability toward carbonate electrolyte and corresponding batteries performance are not desirable. Herein, PMIA membranes coated with ultrathin mussel-inspired polydopamine (PDA) layer were fabricated as separators in LIBs. The introduced amino, quinonyl, and catechol groups in PDA coating could enhance the wettability of the resultant PMIA-PDA separator toward electrolyte. The PMIA-PDA separator had excellent thermal stability, showing a thermal shrinkage of 5.2% at 200 °C. The contact angle of the thermal-treated PMIA-PDA separator could maintain at 26.1°, which decreased by 42.7% compared with the pristine PMIA separator. The PMIA-PDA separator also displayed a high ionic conductivity (0.86 mS cm −1 ) and a low interfacial electric resistance (62.4 Ω). Consequently, the assembled LiCoO 2 /PMIA-PDA/Li battery achieved good cyclic stability with the capacity retention of 84.3% (121.1 mAh g −1 ) after 100 cycles under 30 °C. More significantly, the relevant capacity retention remained at 89.0% (127.5 mAh g −1 ) under 60 °C, which implied a great potential of PMIA-PDA membranes as separators of high-safety LIBs.