POLYMER
·
2022
·
IF 4.432
Xiaodi Dong,Baoquan Wan,Ming-Sheng Zheng,Haiping Xu,Jiefeng Gao,George Chen,Jun-Wei Zha
There is an urgent need for interlayer dielectric materials with ultralow dielectric properties , high temperature resistance and hydrophobicity in the field of microelectronics due to the development of high-density integration and miniaturization of electronic components. Herein, porous polyimide (PI) films were successfully prepared by using ionic liquid (1-Butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF 4 ]) as porogen for the first time. Based on the inherent good compatibility between [BMIM][[BF 4 ] and polyimide, this ionic liquid could be uniformly dispersed in the PI matrix, thus creating a favorable prerequisite for the formation of pores. It was demonstrated that the optimized rearrangement of PI molecular chains induced by etching process of [BMIM][BF 4 ] led to the generation of pores and the reduction of chain spacing, which endow the porous films excellent dielectric, thermal and mechanical properties . The film with the porosity ratio of 85 vol% exhibited minimum permittivity of 1.5 at a wide range from 10 2 to 10 6 Hz, high temperature of 5% weight loss about 532 °C. The porous PI films not only provide the promising ultralow permittivity dielectric materials for the development of modern integrated circuits, but also present potential application in adsorption separation and special electromagnetic detection.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 33
·16064-16079
·
IF 4.682
Zhang Yang,He Jiyu,Yang Rongjie
A series of novel tetraamino phthalocyanine zinc (TAPcZn) micro-crosslinked polyimide films were successfully synthesized by the copolymerization of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride and 4,4′-oxydianiline. The UV–Vis, FTIR, NMR, MALDI-TOF-MS, and SEM–EDS technologies were used to demonstrate the synthesis of TAPcZn. The copolyimide films were mainly characterized via their morphologies, thermal stability, and mechanical properties. As expected, the copolyimide films inherited the optical properties of phthalocyanine compounds and showed good mechanical properties, excellent thermal stability, and flame retardancy with low content of TAPcZn (< 5.0 wt%), regularly. Smooth, uniform, and defect-free copolyimide films all showed good mechanical properties, and the tensile strength of PI with 1.52 wt% of TAPcZn reached 116.9 MPa, which is 19.7% higher than that of pure PI. In addition, as the amount of TAPcZn increases, both the residue char and the initial decomposition temperature of the copolymer film improved significantly, and the fire resistance of PI showed the same rules according to the limiting oxygen index and UL-94 tests. Amazingly, the obtained copolyimides are π -conjugate macrocycle homogeneous copolymers with excellent low dielectric properties. In particular, the 4.49 wt% TAPcZn/PI film showed an ultra-low dielectric constant of 2.326 (at 1 MHz) and a dielectric loss of less than 0.007. Therefore, the copolyimide films containing TAPcZn are highly prospective candidates as high-performance flexible substrates and dielectrics for electronics devices. Graphical Abstract
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Xi Chen,Nana Wang,Guining Chen,Zhenggang Wang,Gongping Liu,Rongfei Zhou,Wanqin Jin
Mixed-matrix formulation is a promising method to overcome permeability-selectivity trade-off of polymers with incorporation of fillers with well-defined nanopores . The filler properties play a key role in determining the performance of mixed-matrix membrane (MMM). In this work, for the first time, we explored the critical effect of filler structural integrity on separation performance of MMM. Typically, micron as-synthesized, submicron as-synthesized and submicron ground SAPO-34 zeolites were incorporated into 6FDA-DAM polyimide , respectively. The interface compatibility between two phases was ensured by (3-aminopropyl) trimethoxysilane (APTMS) modification on SAPO-34 fillers. It was found that the directly synthesized micron and submicron fillers contributed to enhance the CO 2 /CH 4 separation performance whereas the submicron ground filler lowered the CO 2 permeability. Notably, incorporating 30 wt% micron as-synthesized SAPO-34 into 6FDA-DAM enhanced the CO 2 permeability by 68% and CO 2 /CH 4 by 37%, surpassing the performance upper-bound. Moreover, the hydrogen bonding between the filler and polymer matrix endowed the membrane with outstanding plasticization resistance with CO 2 partial pressure up to 20 bar. Adsorption isotherms and Maxwell model prediction revealed that the filler transport properties could be significantly affected by commonly-used methods of reducing the filler size. A decreased structural integrity was identified in the sequence of micron as-synthesized, submicron as-synthesized and submicron ground fillers. This work highlights the importance of a careful balance between structural integrity and crystal size of filler, and reliable routes to obtain nanofillers with desirable structural integrity as pursuing high-performing MMM toward practical application.
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高影响因子
Advanced Membranes
·
2025
·
IF 9.5
Bingbing Gao,Yiran Peng,Ming Wu,Hua Ma,Jianchao Sun,Peng Zhang,Xingzhong Cao,Like Ouyang,Xiaobin Fu,Chunfang Zhang,Yunxiang Bai,Lijun Liang,Yang Liu,Liangliang Dong
Polyimide membranes have attracted considerable attention for gas separation applications; however, achieving efficient helium (He) separation remains a significant challenge due to the low fractional free volume ( FFV ) and poorly controlled pore size distribution. Here, we report a novel three-in-one polyimide-based blended membrane constructed from a polymer (6FDA-TFMB) and alkynyl-based polyimide (EBPA-TB) matrix via thermal crosslinking. By carefully designing membrane synthesis and structure, the resulting membrane achieves the “1+1>2” effect: (i) high He selectivity derived from reinforced interphase adhesion and size-sieving ability due to the hydrogen bonding and similar structure between 6FDA-TFMB and EBPA-TB; (ii) high He permeability derived from the rigid cross-linked network distorting the EBPA-TB chain packing and generating additional free volume; (iii) high anti-aging performance derived from the thermal crosslinking preventing microstructural rearrangements. The optimal membrane an unprecedented combination of high He permeability (51.24 Barrer), excellent He/N 2 selectivity (146.40) and remarkable aging resistance (less than 3.97 % of permeability decrease over 50 days), outperforming the performance of state-of-the-art polyimide-based blended membranes for He purification. This three-in-one blended membrane construction strategy provides a general toolbox for the development of next-generation, high-performance blended membranes with desirable performance for diverse industrial applications.
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产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 7
·3694-3704
·
IF 2.936
Songlv Qin,Mingjun Cui,Shihui Qiu,Haichao Zhao,Liping Wang,Afang Zhang
In this study, to achieve a homogeneous dispersion of nanodiamond (ND) in a polyimide (PI) matrix and a strong interfacial adhesion between ND and the PI matrix, a biomimetic nondestructive dopamine chemistry was employed for surface modification of ND. FTIR and Raman spectroscopy studies revealed that self-polymerization of dopamine could produce thinner polydopamine (PDA) layers on the ND surface via spontaneous oxidation and the intermolecular cross-linking reaction of PDA molecules. The structure and morphology of PDA–ND were studied by FTIR, SEM, and Raman spectroscopy, which verified the π–π interactions between PDA and ND. The facile dispersion of PDA–ND in a polyamic acid prepolymer made it possible to obtain PI/ND composites with no obvious ND aggregation. The effect of PDA–ND nanoparticles on the thermal, mechanical and tribological properties of the resulting PI/PDA–ND composites were evaluated, and the results showed that the incorporation of PDA–ND could increase the hardness, tensile strength, storage modulus, as well as the wear resistance properties. PI/PDA–ND composites prepared in this study showed that PDA–ND is a promising nanoreinforcing filler for PI composites.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Ying Zhang,Haijian Ou,Huixian Liu,Yangli Ke,Weiju Zhang,Guiying Liao,Dongsheng Wang
In this study, polyimide (PI)-based carbon nanofibers (CNFs) were prepared via electrospining polyamic acid solutions followed by thermal imidization and carbonization . And its versatile adsorption performance for removal of 2,4-dichlorophenol (2,4-DCP), methylene blue (MB) and tetracycline (TC) was evaluated. PI-based CNFs with a high specific surface area of 715.89 m 2 g −1 exhibited a maximum adsorption of 483.09 mg g −1 , 272.48 mg g −1 and 146.63 mg g −1 for 2,4-DCP, MB and TC, respectively. The MB adsorption efficiency was highly pH-dependent with an optimal pH 11, while the CNFs performed well towards TC and 2,4-DCP adsorption in the wide pH range of 4–7 and 3–7. Kinetics and isotherm experiments were fitted well with pseudo-second-order kinetics model and Langmuir model, respectively. Thermodynamic parameters showed that adsorption was spontaneous and endothermic. Moreover, the reusability of PI-based CNFs was evaluated, and the result showed that the removal of 2,4-DCP, TC and MB was kept its high efficiency after 5 consecutive cycles. This study demonstrated that the CNFs should be a powerful adsorbent for the removal of a great number of organic pollutants from aqueous environments.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Junchuan Wang,Ying Sun,Pengna Wang,Xuemin Yu,Hongbing Shi,Xueqin Zhang,Hong Yang,Baoping Lin
Novel one-dimensional (1D) core-shell structured BaTiO 3 @ZrO 2 (BT@ZrO 2 ) nanofibers have been synthesized through coaxial electrospinning. Homogeneous composite films containing 1D BT@ZrO 2 nanofibers as filler and polyimide (PI) as the polymer matrix were fabricated. The depolarizing ZrO 2 layer with moderate dielectric constant was introduced onto the BT nanofibers surface and decreased the electric filed caused by the tremendous contrast between the PI matrix and the BT nanofibers in permittivity. The energy density and breakdown strength of the BT@ZrO 2 /PI composites can be substantially enhanced. It was established that the 2 vol% BT@ZrO 2 /PI composite film has the maximum energy density of 2.53 J/cm 3 at 361 kV/mm, which is ≈ 180% higher than that of the pristine PI (1.40 J/cm 3 at 303 kV/mm). Furthermore, finite element simulation was carried out to understand the effect of ZrO 2 layer on the electric field distribution. This work demonstrates the advantages of the moderate inorganics layer in increasing the breakdown strength and highly enhancing the energy density of the polymer based composites.
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高影响因子
Polymers
·
2021
·Vol. 13
·期 21
·3622
·
IF 4.329
Boheng Yuan,Bin Zhao,Zhi Cong,Zhi Cheng,Qi Wang,Yafei Lu,Xiaogang Han
Solid-state batteries (SSBs) have attracted considerable attention for high-energy-density and high-safety energy storage devices. Many efforts have focused on the thin solid-state-electrolyte (SSE) films with high room-temperature ionic conductivity, flexibility, and mechanical strength. Here, we report a composite polymer electrolyte (CPE) reinforced by electrospun PI nanofiber film, combining with succinonitrile-based solid composite electrolyte. In situ photo-polymerization method is used for the preparation of the CPE. This CPE, with a thickness around 32.5 μm, shows a high ionic conductivity of 2.64 × 10−4S cm−1at room temperature. It is also fireproof and mechanically strong, showing great promise for an SSB device with high energy density and high safety.
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高影响因子
COMPOSITE INTERFACES
·
2019
·
IF 2.025
Guoliang Zhang,Jie Chen,Yahui Meng,Shihua Wang,Zhu Long
Functionalized modified SiO2 was prepared by a mild and simple dip coating method, and a layer of functionalized modified SiO2 coating was introduced onto the carbon fiber surfaces not only to improve the surface wettability and activity of carbon fiber, but also strengthen the interphase of the carbon fiber/polyimide composite. The successful functionalization of SiO2 by bis[3-(triethoxysilyl)propyl] tetrasulfide (TESPT) silane was confirmed. Moreover, a uniform coating with well-dispersed particles on a carbon fiber surface was achieved with a 1.0 wt% addition of TESPT-modified SiO2 (TESPT@SiO2) particles. Under this condition it was observed that the interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) augmentation was 26.37% and 38.27%, respectively, in comparison with carbon fiber composite coated only with polyimide resin. The functionalized modified SiO2 coating could effectively heal the surface defects of fiber, and the fiber tensile strength increased by more than 10.61%. This study provides a scalable, simple, and cost effective method of simultaneously increasing the interfacial strength of composites.
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2016
·
IF 2.725
Yan Wang,Qiang Gao,Qingliang You,Guiying Liao,Hua Xia,Dongsheng Wang
Porous organic frameworks (POFs) have aroused considerable interest owe to its high surface areas , superior chemical and thermal stabilities, good mechanical and abundant porosity. In this study, a porous polyimide (PI) with abundant amine groups was synthesized by the reaction of melamine and pyromellitic dianhydride. And its versatile adsorption performance towards organic pollutants, including azo dye (methyl orange (MO)) and antibiotic (tetracycline (TC)) was investigated. The PI was characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA), and N 2 adsorption-desorption techniques. The obtained product possessed high thermal stability and exhibited a high surface area (635.5 m 2 ·g − 1 ) and a large pore volume (0.98 cm 3 ·g − 1 ). The pH effect study showed that MO adsorption was highly pH-dependent with an optimal pH 3, while the TC adsorption was effective in the pH range of 6–8. Batch adsorption experiments were carried out to study adsorption kinetics and adsorption thermodynamics. The result showed that the kinetics experimental data were fitted to pseudo-second-order kinetics model better, and adsorption isotherm could be described by the Langmuir isotherm model perfectly. The maximum adsorption capacities calculated from the Langmuir isotherm model are 609.8 and 155.8 mg/g at 318 K for MO and TC, respectively. The thermodynamic study showed that the adsorptions of TC and MO on PI were spontaneous (Δ G < 0) and endothermic (Δ H > 0). Findings in this study demonstrated that the porous PI should be a powerful adsorbent in organic pollutants removal.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Mengjie Sun,Meng Li,Xu Zhang,Cuiming Wu,Yonghui Wu
Composite anion-exchange membranes with porous structures have been successfully prepared by incorporating quaternized graphene oxide (QGO) into P84 co-polyimide, and then undergoing the phase inversion, amination and quaternization processes. The membranes’ porous structures can be readily adjusted by the category of non-solvent during the phase inversion process. Large finger-like voids are present in the lower parts of the membrane cross sections by using water or 50% isopropanol aqueous solution, which facilitate the entrance of polyethylenimine chains into the membrane matrix, leading to higher degree of amination and quaternization. The incorporation of QGO does not influence the membrane morphology obviously, but can further enhance the ion exchange capacity (1.23–1.65 mmol/g) and decrease the membrane area resistance (1.6–1.9 Ω cm 2 ). The QGO-P84 composite membranes are used in bipolar membrane electrodialysis (BMED) for the removal of boron from synthetic model solutions (Na 2 B 4 O 7 ·10H 2 O, 1000 mg B/L). The finger-like pores decrease the steric resistance of boron transport, while the incorporation of QGO improves the membrane electro-chemical properties and thus the BMED performances. The separation efficiency is 76.6% after running 3 h under 30 V, the current efficiency is 94.9% and the energy consumption is 26.16 kW h/kg by using the optimal composite membrane. The BMED performances are better than those of commercial membrane CJMA-3 (separation efficiency of 51.6%, current efficiency of 81.2%, and energy consumption of 30.56 kWh/kg). Hence, the QGO-P84 composite membranes are effective for removal and recovery of boron from aqueous solution through BMED method.
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Chenjie Wei,Zhifu He,Ligang Lin,Qi Cheng,Kai Huang,Sisi Ma,Li Chen
A simple strategy is proposed for high performance polyimide nanofiltration (PI-NF) membranes by optimization of a synergistic imidization reaction. Soluble poly(amic acid) polymers with partial imidization was successfully controlled and fabricated by chemical imidization. With the product as a matrix, NF membranes with an integrally skinned asymmetric architecture were obtained by phase inversion and subsequent thermal imidization. The brittle and ruptured defects caused by directly high temperature conversion for fabricating PI-NF membranes were effectively avoided. The prepared membrane showed high rejections for dye, PEG and typical salts. The fabricated PI-NF membranes were endowed with a high permeance of isopropyl alcohol [approximately 1 L/(m 2 h bar)] and a high rejection of rose Bengal (greater than 92%). The molecular weight cut-off of PI-NF membrane is below 800 Da. The pure water flux of PI-NF membrane prepared under optimized conditions was approximately 20 L/(m 2 h) and the rejection for Na 2 SO 4 was 93.91% at 5 bar. The rejection for different salts followed the order: Na 2 SO 4 > MgSO 4 > NaCl > MgCl 2 , revealed that Donnan exclusion theory and steric hindrance effect dominated the rejection mechanism. Furthermore, the NF membranes showed excellent stability over a long-term filtration process.
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高影响因子
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