POLYMER
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2024
·
IF 4.1
Siqi Zhang,Shu Wu,Qi Wang,Mengxiang Guan,Bowen Yang,Guirong Peng,Xiaojia Zhao
P(VDF-HFP) is widely used in transistors, electret and artificial skin due to its excellent dielectric properties . In order to dramatically improve its dielectric constant, conductive fillers are used for doping, but the compatibility is not optimistic between the fillers and the PVDF . In this paper, PEDOT:PSS/P(VDF-HFP) all-organic films with interpenetrating network structure were prepared by the addition of H 2 O. The dielectric constant of the film with 0.5 wt % PEDOT:PSS reached up to 323 and the tanδ was only 0.48 (1 k Hz, 18 °C). The addition of the H 2 O made the small amount of PEDOT:PSS evenly distribute in the P(VDF-HFP), as a result, the percolation threshold decreased. Besides, molecular chains of PEDOT:PSS were overlapped to form a uniform network. This paper provided a novel preparation method for a uniform film with two kinds of matters with different compatibility.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
E-POLYMERS
·
2022
·Vol. 22
·期 1
·763-774
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IF 3.074
Huizhi Liu,Qilin Mei,Guomin Ding,Han Xiao,Shuhui Chen,Zhixiong Huang
The percolation thresholds of poly ether ether ketone/graphene (PEEK/Gr) composites in most studies are high due to the random distribution of Gr in the matrix. Here, aminated poly-ether-ether-ketone/graphene network (PEEK-NH 2 /GN) nanocomposites were prepared by electrostatic adsorption of PEEK-NH 2 with positive charges and graphene oxide with negative charges, followed by in -situ reduction and hot-pressing. The GN structure of composites was well presented in the images of scanning electron microscope. The PEEK-NH 2 /GN nanocomposites exhibited excellent electrical conductivity with a maximum conductivity of 0.0634 S·cm −1 and a percolation threshold as low as 0.25 vol%. In addition, the maximum tensile strength of nanocomposites was reached at 93 MPa when the Gr content was 0.5 wt%. We believe that this approach is a new avenue for the production of low filler high conductive polymer composites with potential commercial prospects in various fields.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Zheng Zheng,Yongliang Zhao,Zhangfan Ye,Jianhua Hu,Haitao Wang
Hypothesis: Constructing a segregated network in electrically conductive polymer composites (ECPCs) is an effective method to lower the electrical percolation threshold. The segregated network structure can be formed naturally via polymerizing Pickering high internal phase emulsions (HIPEs) because solid particles are assembled at water-oil interfaces. However, most Pickering stabilizers show poor electrical conductivity . In this work, we propose a facile method to prepare lightweight ECPCs with well-controlled segregated structure via Ti 3 C 2 T x -stabilized HIPE templating. Experiments: Hydrophilic Ti 3 C 2 T x flakes are delicately hydrophobized with a double-chain cation surfactant . The morphology of Ti 3 C 2 T x flakes is investigated by transmission electron microscopy (TEM) and atom force microscopy (AFM). The surface properties of modified Ti 3 C 2 T x are characterized by zeta potential and water contact angle tests. The stability of Ti 3 C 2 T x -stabilized emulsions, and the structure of prepared ECPCs are systematically investigated. Findings: Surface modified Ti 3 C 2 T x flakes are used to stabilize water-in-oil (w/o) HIPEs for the first time. After the polymerization of continuous oil phase, ECPCs are successfully prepared with closed-cell porous structure. The pore size and size distribution of porous composites can be tailored by varying the content of Ti 3 C 2 T x flakes. The Ti 3 C 2 T x flakes are mainly immobilized at the water–oil interface and eventually form the segregated network in composites. Combining the unique segregated network and the outstanding metallic conductivity of Ti 3 C 2 T x , the prepared porous polymer composites exhibit good conductivity even with ultralow Ti 3 C 2 T x content of 0.016 vol%.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 16
·3862
·
IF 4.2
Guangyue Shi,Xiaolei Sun,Yao Liu
Percolating composites exhibiting negative permittivity have garnered considerable attention due to their promising applications in the realm of electromagnetic shielding, innovative capacitance devices, coil-less inductors, etc. Nano carbon powder/polyvinylidene fluoride (CP/PVDF) percolating composites were fabricated that exhibit Drude-type negative-permittivity behavior upon reaching the CP percolation threshold. This phenomenon is attributed to the formation of a plasmonic state within the interconnected CP network, enabling the delocalization of electrons under the alternating electric field. Furthermore, a significant (nearly two orders of magnitude) increase in the conductivity of sample is observed at a CP content of 12.5 wt%. This abrupt change coincides with the percolation phenomenon, suggesting a transition in the conduction mechanism. To elucidate this behavior, comprehensive analyses of the phase composition, microstructure, AC conductivity, and relative permittivity were performed. Additionally, the sample containing 5 wt% CP exhibits a remarkably high permittivity of 31.5, accompanied by a relatively low dielectric loss (tanδ < 0.2). The findings expand the potential applications of PVDF, while the fabricated percolating composites hold promise for electromagnetic shielding, antennas, and other electromagnetic devices.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2019
·
IF 6.309
Zhongyang Wang,Kai Sun,Peitao Xie,Yao Liu,Qilin Gu,Runhua Fan
The insulator-conductor percolative composites have been mostly constructed to achieve high permittivity and negative permittivity. In this work, permittivity transition from positive to negative is investigated in acrylic polyurethane-aluminum (APu/Al) percolative composites at radio frequency. Both the high permittivity and negative permittivity are accompanied with low loss due to the self-passivated nature of aluminum . The reactance and ac conductivity are studied to explain the dielectric properties , which provides an essential insight into the universal principles of high permittivity and negative permittivity behaviors in percolative composites. Meanwhile, when the conductive filler content exceeds the percolation threshold, a derived formula of permittivity has been put forward on the basis of the existing theoretical framework of percolation theory. Resourceful dielectric properties of APu/Al percolative composites will make them as potential alternatives for capacitors and metamaterials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Ming-Ke Xu,Ji Liu,Hao-Bin Zhang,Yu Zhang,Xinyu Wu,Zhiming Deng,Zhong-Zhen Yu
Electrically conductive polymer nanocomposites are highly required for efficient electromagnetic interference (EMI) shielding applications. Although two-dimensional transition metal carbide/carbonitride (MXene) nanosheets with metallic electrical conductivity and layered structure show great potential for the construction of interconnected conductance networks in polymer matrices, their preferred stacking feature and intrinsic hydrophilicity inevitably cause poor dispersion in organic polymers, making it challenging to prepare MXene/polymer nanocomposites with high electrical conductivity and satisfactory EMI shielding performances at low MXene contents. Herein, we demonstrate an efficient methodology to prepare highly conductive MXene/polypropylene (PP) nanocomposites with an ultralow percolation threshold for efficient EMI shielding application. By dip-coating MXene nanosheets onto a polyethyleneimine-grafted PP textile, followed by vacuum-assisted compression molding, an interconnected conductance network of MXene nanosheets in the PP matrix is constructed facilely and efficiently. The resultant MXene/PP nanocomposite exhibits an ultralow percolation threshold of 0.027 vol %, a high electrical conductivity of 437.5 S m–1 at a low MXene loading of 2.12 vol %, and an outstanding EMI shielding performance of more than 60 dB within the X-band, superior to most other electrically conductive polymer nanocomposites. This work provides a new approach for fabricating MXene/polymer nanocomposites with outstanding electrical conductivity for high-performance EMI shielding applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2016
·
IF 3.897
Hong-xin Tan,Xue-cheng Xu
Presented here is a novel approach to polymer composite fabrication, achieved under low electrical percolation threshold. Multiwall carbon nanotubes (MWNT)/polyaniline (PANI) hybrid nanoparticles with high electrical conductivity have been readily prepared by in-situ polymerization at 5 wt% MWNT. Three matrices, polyvinyl chloride (PVC), poly (methyl methacrylate) (PMMA) and polystyrene (PS), were mechanically blended with MWNT/PANI nanoparticles and percolated at respective weight percentages of 0.25, 0.85 and 1.25. As evidenced by X-ray photoelectron spectroscopy, the π-π interaction between MWNT and PANI supports enhances carrier mobility , which leads to high electrical conductivity of MWNT/PANI nanoparticles at low MWNT content. FESEM and Hall Effect Measurement System analyses show strong doping effect between nanoparticles and matrices, which provides excellent dispersion of MWNT/PANI nanoparticle in the matrix. Better charge transition is obtained for MWNT/PANI/polymer composites by replacing the insulating polymer with the conductive and less-resistant PANI polymer. The same change is also responsible for the hybrid nanoparticle's low electrical percolation.
研究领域:
材料科学
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化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2023
·
IF 3.6
Xiaoting Song,Guangyue Shi,Guohua Fan,Yao Liu,Runhua Fan
Meta-materials with fascinating dielectric behavior have drawn much attentions for their potential applications recently. Herein, percolating GR/PVDF composites consisting of GR sheets homogeneously dispersed in PVDF matrix are fabricated via hot-pressing method in 20 Hz-1 MHz frequency regions, of which simultaneously realizing negative permittivity with low percolation threshold. It’s demonstrated that negative permittivity of GR/PVDF composites are resulted from the low-frequency plasma oscillation of free electrons, and a universal regulatory mechanism of Drude model is analyzed. At the same time, rapid formative 3D GR conductive networks contributed to the low percolation threshold (7.78wt%) of composites. Moreover, it is shown that electrical percolation occurred in samples as GR content exceeds percolation threshold, indicating a typical metal-like behavior. In addition, the reactance is discussed according to the equivalent circuit analysis. This work constructed the meta-composites with low filler content, which is benefit for practical applications in electromagnetic devices. This article is protected by copyright. All rights reserved.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2020
·
IF 7.635
Yanpei Fei,Feng Chen,Wei Fang,Lixin Xu,Shilun Ruan,Xianhu Liu,Mingqiang Zhong,Tairong Kuang
In this work, high strength , flexible and cycling-stable piezoresistive thermoplastic polyurethane (TPU)/multi-wall carbon nanotubes (MWCNTs) composite foams were fabricated by a solution-blending method and supercritical carbon dioxide (ScCO 2 ) foaming process. The microcellular structure (1–10 μm) of the TPU/MWCNTs composites enhanced the energy storage and reduced the conductive percolation threshold. The compressive strength and compressive modulus of the composites were 1.05 MPa and 3.79 MPa. Percolation threshold of the foamed composites decreased from 0.90 vol% to 0.31 vol%. The prepared TPUC5.0 foam (the content of MWCNTs is 5%) had high sensitivity, wide strain range, and stable resistance. The piezoresistive current was relatively stable, and showed high repetitive force-electric conversion behavior in 1000 cycles. Thus, polymeric foams are suitable for real-time monitoring of human foot movement using wearable strain sensors.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF REINFORCED PLASTICS AND COMPOSITES
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2013
·
IF 0.902
Danqing Chen,Guohua Chen
Thermoplastic polyurethane/graphene nanoplatelets conductive composite was in situ synthesised by ball milling at room temperature, using polytetramethylene glycol as soft segment, 4-methyl-m-phenylene diisocyanate as hard segment, 1,4-butanediol as chain-extending agents, graphene nanoplatelets as conductive filler. Carbon black was used as contrast conductive filler, stir was used as contrast method. The mechanisms and influence of different ball milling time to exfoliate layered graphene nanoplatelets and compound with thermoplastic polyurethane resin were studied. The morphology, electrical, mechanical and thermal properties of thermoplastic polyurethane/graphene nanoplatelets composite were investigated too. It showed that ball milling was an effective method to prepare thermoplastic polyurethane/graphene nanoplatelets conductive composite of low loading level by avoiding aggregation of graphene nanoplatelets. The percolation threshold effect of thermoplastic polyurethane/graphene nanoplatelets composite by ball milling 6 h occurred at the content around 2 wt% of the graphene nanoplatelets, which was much lower than 6 wt% of that prepared by stir. Besides, thermoplastic polyurethane/graphene nanoplatelets composite showed much better conductive and mechanical properties than thermoplastic polyurethane/carbon black composite.
研究领域:
材料科学
·
复合材料
·
纳米技术
✓ 已验证
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Jia-Xing Guo,Tao Gong,Kai Ke,Zheng-Ying Liu,Jun Chen,Wei Yang
Porous conductive polymer composites are very attractive for static pressure sensing due to high sensitivity and good elasticity contributed by the porous structure , while they are hard to detect dynamic pressure. Herein, we report a porous conductive poly (vinylidene fluoride) (PVDF) composite capable of detecting static and dynamic pressure over a pressure range of 0–1 MPa, which was fabricated by melt mixing PVDF, polyethylene oxide (PEO) and carbon nanofillers , followed by etching PEO with water. Such porous PVDF composites have a very low percolation threshold (0.035 wt%) of carbon nanostructures (i.e., branched carbon nanotubes) thanks to the selective distribution of conductive fillers in the pore wall after etching. At the same time, the pore size and porosity of the porous PVDF composites can be tuned by the molecular weight (M w ) and blending ratios of two polymers, leading to the kinetically-tailorable blend morphology for tunable mechanical and electrical properties. The as-fabricated porous PVDF composites with a good combination of mechanical properties and electrical conductivities , which can be used as pressure sensors toward wide-range (0–1 MPa) dynamic and static pressure sensing. Such pressure sensors demonstrate potential applications in detecting the degree of finger bending, distinguishing the walking and running, and monitoring a series of technical movements in playing soccer, i.e., static and dynamic exercises.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）