COMPOSITES SCIENCE AND TECHNOLOGY
·
2018
·
IF 5.16
Weiyan Li,Zhongqian Song,Jing Qian,Zhongyang Tan,Huiying Chu,Xianyou Wu,Wei Nie
Polymer-based composites with excellent dielectric and thermal conductive properties attract ever-increasing attentions from researchers due to the irreplaceable role in energy storage system and electrical devices. Herein, poly(vinylidene fluoride) (PVDF)-based ternary composites were fabricated by adding small amount of poly(dopamine) coated boron nitride (DBN) and electrochemical exfoliated graphene (EEG) into PVDF matrix. Due to the high degree of π-conjugation and good dispersity of EEG, high dielectric constant could be achieved with a very small addition. Meanwhile, after a small amount of DBN was introduced into the EEG/PVDF system, high dielectric constant, low dielectric loss and excellent thermal conductivity were integrated into the EEG/DBN/PVDF ternary composites due to the synergistic effect of DBN and EEG. Compared with the dielectric constant of 591 and loss of 1.21 for EEG(2.0%)/PVDF, the dielectric constant of the DBN(3.1%)/EEG(2.0%)/PVDF can reach up to 6655 and the dielectric loss can be suppressed below 0.83 at 10 2 Hz. In addition, the thermal conductivity of the ternary composite film can reach up to 1.33 W m -1 K -1 , which is 5.68 times more than that of pure PVDF (0.234 W m -1 K -1 ). This work provides a simple and efficient strategy to exploit novel polymer based composites with excellent dielectric and thermal conductive properties for extensive applications in electronics and energy storage systems.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
NPG Asia Materials
·
2022
·Vol. 14
·期 1
·1-11
·
IF 10.761
Jian Gang,Jiao Yong,Feng Liang,Meng Qingzhen,Yang Ning,Zhu Shangtao,Lü Minfeng,Wong Ching-Ping
Dielectric substances exhibit great potential for high-power capacitors due to their high stability and fast charge–discharge; however, a long-term challenge is to enhance energy density. Here, we propose a poly(vinylidene fluoride) (PVDF) composite utilizing BaTiO 3 nanoparticle@TiO 2 nanosheet (BT@TO ns) 2D nanohybrids as fillers, aiming at combining the interfacial strategy of using a core–shell filler and the electron scattering of a 2D filler to improve the energy density. With 4 wt% filler, the composite possesses the largest breakdown strength ( E b ) of 561.2 MV m −1 , which is significantly enhanced from the 407.6 MV m −1 of PVDF, and permittivity of 12.6 at 1 kHz, which is a 23% increase from that of PVDF. A superhigh energy density of 21.3 J cm −3 with an efficiency of 61% is obtained at 550 MV m −1 . The 2D BT@TO ns-filled composite exhibits a higher energy density than composites filled with core–shell 1D BT@TO nws or non-core–shell 0D BT, 1D TO, or 2D TO particles. The E b and energy density improvements are attributed to the buffer layer-based interface engineering and enhanced area scattering of electrons caused by the 2D hybrids, an effect similar to that of a ping-pong paddle to scatter electric field-induced charge migrations in composites. Thus, an effective hybrid strategy is presented for achieving high-performance polymer composites that can be used in energy storage devices.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
IET Nanodielectrics
·
2020
·Vol. 3
·期 3
·94-98
·
IF 0
Ming-Sheng Zheng,Chong Zhang,Yu Yang,Zhao-Liang Xing,Xin Chen,Shao-Long Zhong,Zhi-Min Dang
Polymer nanocomposites with improved dielectric permittivity and high breakdown strength are extremely desirable for the flexible electronic devices and power systems. The compatibility of fillers and polymer matrix is important in determining the dielectric and breakdown strength properties. The core–shell structure concept is useful to improve the compatibility of fillers with polymer matrix. Herein, an organic thermoplastic urethanes (TPU) polymer shell was successfully grafted on the surface of barium titanate (BaTiO 3 , BT) and such a TPU shell improved the permittivity and breakdown strength of TPU@BT/PVDF polymer nanocomposites greatly. The permittivity of TPU@BT/PVDF nanocomposites with 12 wt% fillers at 10 2 Hz was up to 13.5, which was 1.5 times higher than that of pure poly(vinylidene fluoride) (PVDF). The improvement of the dielectric properties could be attributed to the enhanced interfacial polarisation between BT nanoparticles and TPU shell. Besides, the compatibility of BT nanoparticles and PVDF matrix was improved after the introduction of TPU shell. Accordingly, a highest breakdown strength value about 373 MV/m was obtained for the TPU@BT/PVDF nanocomposites with 7 wt% fillers. The core–shell strategy could be extended to a variety of inorganic fillers to improve the dielectric and breakdown strength properties of polymer nanocomposites.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Qingguo Chi,Xubin Wang,Changhai Zhang,Qingguo Chen,Minghua Chen,Tiandong Zhang,Liang Gao,Yue Zhang,Yang Cui,Xuan Wang,Qingquan Lei
In this paper, the one-dimensional (1D) Al2O3 nanofibers (Al2O3 NFs), CaCu3Ti4O12 nanofibers (CCTO NFs), and core–shell CaCu3Ti4O12@Al2O3 nanofibers (CCTO@Al2O3 NFs) were prepared via electrospinning technique. The surface modification with dopamine (PDA) was employed for the above three kinds of nanofibers before being filled the PVDF matrix, which can improve their dispersion and compatibility with the matrix. The microstructure, dielectric properties, leakage current density, breakdown strength, and energy storage performance of composites with three kinds of filler, CCTO NFs/PVDF, Al2O3 NFs/PVDF, and CCTO@Al2O3 NFs/PVDF, were systematically investigated. By comparing the three composites, it can be found that energy storage density of CCTO@Al2O3 NFs/PVDF were enhanced compared to that of pure PVDF, which can be attributed to improvement of polarization and electric breakdown strength. The energy density of 8.46 J/cm3 at 340 kV/mm was obtained for 4 vol % CCTO@Al2O3 NFs/PVDF nanocomposites, which is 230% larger than that of PVDF (3.68 J/cm3 at 330 kV/mm). This study provides a method for preparing high energy storage PVDF-based composite film which can be used for the next generation of dielectric capacitors.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2021
·
IF 9.078
Yanli Li,Bing Zhou,Yong Shen,Chengen He,Bo Wang,Chuntai Liu,Yuezhan Feng,Changyu Shen
The durability and large-scale production of Ti 3 C 2 T x MXene-based composites are the main obstacles in industrialized application. Herein, a scalable blade coating method is demonstrated for fabricating the flexible and durable polyvinylidene fluoride (PVDF)/Ti 3 C 2 T x MXene layered films with compact hierarchical brick-and-mortar structure. The highly aligned MXene nanosheets make the obtained PVDF/MXene films with high electrical conductivity from 21.1 to 214.6 S cm −1 . In combination to the multiple wave reflection in hierarchical layered structure and the interfacial polarization between dielectric matrix and MXene, PVDF/MXene films reveal excellent electromagnetic interference (EMI) performance with an optimal specific EMI shielding effectiveness (SSE/t) of 19504.8 dB cm 2 g −1 at only 17 μm thickness. More importantly, the PVDF/MXene film can withstand the damages from mechanical deformation , hot/cold attack and chemical corrosion, meanwhile maintain a stable EMI shielding performance within floating of 5%. Besides, arising from the surface plasmon resonance effect and high electrical conductivity, the PVDF/MXene film reveals photo/electro-thermal heating abilities with rapid response time, high stability and controllability, which ensure their reliable EMI shielding performance under extremely cold conditions.
研究领域:
材料科学
·
电子工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Wenning Qi,Liuyang Li,Ruolin Han,Yanbin Hou,Zheng Zhou,Guang-Xin Chen,Qifang Li
Using high-dielectric inorganic ceramics as fillers can effectively increase the dielectric constant of polymer-based composites. However, a high percentage of fillers will inevitably lead to a decrease in the mechanical toughness of the composite materials. By introducing high aspect ratio copper calcium titanate (CaCu3Ti4O12) nanowires (CCTO NWs) and graphene as fillers, the ternary poly(vinylidene fluoride) (PVDF)-based composites (CCTO NWs–graphene)/PVDF with a significant one-dimensional orientation structure were prepared by hot stretching. CCTO NWs and graphene are arranged in a directional manner to form a large number of microcapacitor structures, which significantly improves the dielectric constant of the composites. When the ratio of CCTO NWs and graphene is 0.2 and 0.02, the oriented composites have the highest dielectric constant, which is 19.3% higher than the random composites, respectively. Numerical simulations reveal that the introduction of graphene and the construction of the one-dimensional oriented microstructure have a positive effect on improving the dielectric properties of the composites. This study provides a strategy to improve the dielectric properties of composite materials by structural design without changing the filler content, which has broad application prospects in the field of electronic devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2025
·
IF 2.5
Cheng Yongchao,Tong Feng,Huang Sheng,Chen Zheng,Zhao Yulong,Gu Xiuquan
The monitoring of body temperature is critical for assessing the health conditions of a critically ill patient. Flexible temperature sensors provide direct contact with human skin, ensuring stable and continuous monitoring of a person’s body temperature. In this study, an affordable and readily available polyvinylidene fluoride (PVDF) was used as the polymer matrix for fabricating a wearable temperature sensor. Through a simple solution mixing process, both conductive carbon black (CB) and ionic liquid were uniformly dispersed in the flexible PVDF composite for enhancing its conductivity and stability. The influence of CB addition amounts was investigated with respect to surface morphology, microstructure, and properties. The results showed that the composite with 6% CB addition had the highest sensitivity of 3.07%/°C, with a minimum detectable temperature difference of 1°C and short response/recovery times of 6.66 s/15.63 s at Δ T = 10°C. Additionally, the response/recovery curves of this device demonstrated good cycle stability. Furthermore, the sensor retained its superior performance even after extended operational periods, confirming the long-term stability and reliability of this thin-film sensor. The sensor shows great promise for physiological signal detection and holds substantial potential for applications in wearable electronics. This work offers a new possibility for the low-cost, large-scale fabrication of flexible temperature sensors in the future. Graphical
研究领域:
材料科学
·
生物医学工程
·
传感技术
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2019
·
IF 6.282
Yu Lu,Xu Xie,Wen-yan Wang,Xiao-dong Qi,Yan-zhou Lei,Jing-hui Yang,Yong Wang
Zinc oxide (ZnO) nanoparticles and graphene oxide (GO) nanosheets are self-assembled to form the hybrid ZnO@GO nanoparticles through the simple solution compounding processing with the aid of ultrasonic treatment. There is a good interaction between ZnO and GO, which promotes the deposition of ZnO nanoparticles on the surface of GO nanosheets and the exfoliation of GO nanosheets. Microstructure and morphology characterizations of the poly(vinylidene fluoride) (PVDF)-based composites show that the PVDF/ZnO@GO composites exhibit largely improved dispersion of fillers compared with the PVDF/GO composites. At high filler content, ZnO@GO nanoparticles also induce the change of α-form to β-form PVDF. The hybrid ZnO@GO nanoparticles endow the composites with high relative permittivity, low dielectric loss and high breakdown strength . Furthermore, the composite samples also show good flexibility. This work confirms that incorporating the hybrid nanoparticles that are composed of semi-conductive fillers is an efficient way to prepare the dielectric composites with promising properties.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 50
·505204
·
IF 3.874
Yuanzhen Du,Dawei Cao,Yuan Liu,Quan Wang
Adding conductive graphene into polyvinyliden1 fluoride (PVDF) is an effective method to improve the dielectric properties. However, the high conductivity and uniform distribution of graphene in PVDF matrix still meet challenges. In this work, electrochemical exfoliated graphite (EEG) with good conductivity and solution dispersion is used to prepare PVDF/EEG films. By this method no specific conditions are needed such as reduction or hot press. The dielectric properties and flexibility of PVDF/EEG films of different concentrations of EEG are investigated. Especially, when EEG content is 2.6 wt%, composite film has a high dielectric constant of 86 and a low dielectric loss of 0.9 (100 Hz). Simultaneously, the tensile strength of the film was up to 55.1 MPa. The preparation method is simple and convenient, and the obtained material has high dielectric constant and tensile strength. This method paves the way for the application of flexible electronic sensing equipment.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Energy Materials
·
2023
·Vol. 13
·期 11
·2203587
·
IF 27.8
Tongguang Zhu,Hang Zhao,Na Zhang,Chuying Zhang,Lei Yin,Zhi-Min Dang,Jinbo Bai
Dielectric capacitors are fundamental energy storage components in electronics and electric power systems due to their unique ultrahigh power density. However, their relatively low energy storage density is a long-standing challenge which greatly limits their practical application range. Chitosan (CS) and montmorillonite (MMT) are two kinds of materials that exist abundantly on the earth with natural surface charges. The positively charged CS and negatively charged MMT can be self-assembled into the typical sandwich-structured CS/MMT/CS 2D structure through an electrostatic attraction. Loading these surface-charged sandwich-structured nanosheets into poly(vinylidene fluoride)-based composite with a weight fraction as tiny as 0.3 wt.%, an ultrahigh energy storage density of 32.5 J cm −3 accompanied with a high efficiency of 64% are concurrently achieved with a very low cost and scalable process. Guided by finite element simulation, it is revealed that a number of electric potential wells that exist in the charged sandwich nanosheets impede the acceleration of internal charges and hinder the growth of electrical trees. The results offer a novel paradigm for exploring ultrahigh energy storage density capacitors in an economical way.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2024
·
IF 8.3
Yang Zhou,Jiahao Sun,Zhaoyang Li,Bing Zhou,Chuntai Liu,Yuezhan Feng
The integral structure design is equally crucial to the regulation of electromagnetic components in microwave absorbing materials. In this work, magnetic MXene/polyvinylidene fluoride composites with integral nacre-like structure were prepared by successive hot-pressing process to realize the layered arrangement of Ni anchored MXene (Ni@MXene). The order degree of Ni@MXene from random to orientation can be adjusted by gradually changing compression ratio. Interestingly, increasing the orientation degree of Ni@MXene effectively improves the dielectric constant, minimal reflection loss ( RL min ) and effective absorption bandwidth (EAB) of the layered composites. This is attributed to the improved loss ability by increasing the contact areas between Ni@MXene and vertically incident electromagnetic waves , inducing multiple scattering/reflection effect, and the formation of localized conductive pathways. As a result, the layered composite with optimal layered structure delivers the best electromagnetic microwave absorption performance with a RL min of −69.8 dB and an EAB of 4.77 GHz. Besides, increasing the orientation degree can also optimize the mechanical properties of the layered composites, with the maximum tensile strength and toughness of 32.6 MPa and 115.0 MJ m −3 , respectively. Therefore, this work proves the adjustability of absorption performance by changing the distribution of absorbents, and integrates the structure and function for microwave absorption materials .
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Chemical Science
·
2019
·Vol. 10
·期 35
·8224-8235
·
IF 9.556
Xu Xie,Zhen-zhen He,Xiao-dong Qi,Jing-hui Yang,Yan-zhou Lei,Yong Wang
Polymer dielectric composites have widespread applications in many fields ranging from energy storage, microelectronic devices, and sensors to power driven systems, etc. and attract much attention of researchers. However, it is still challenging to prepare advanced polymer dielectric composites with a high dielectric constant (ε′), low dielectric loss (tan δ) and simultaneously high breakdown strength (Ebd). In this work, conductive polypyrrole (PPy) nanoparticles were in situ synthesized in a reaction system containing the common barium titanate (BaTiO3, BT) or hydroxylated BaTiO3 (BTOH) particles, and then the PPy@BT and PPy@BTOH composite particles were incorporated into poly(vinylidene fluoride) (PVDF) to prepare the composites. The morphologies and microstructures of the PPy@BT and PPy@BTOH composite particles and the corresponding PVDF composites were comparatively investigated. The results showed that the PPy@BTOH composite particles had a ‘mulberry’-like morphology with a rough surface and the self-assembled structure could be maintained in the PVDF composites, which was apparently different from the PVDF/PPy@BT composites, in which most of the PPy nanoparticles dissociatively dispersed in the PVDF matrix. Electrical conductivity measurements showed that at high particle content (≥20 wt%), the PPy@BTOH composite particles endowed the composites with lower electrical conductivity compared with the PPy@BT composite particles. Dielectric property measurements showed that the ‘mulberry’-like PPy@BTOH composite particles endowed the PVDF composites with extremely high ε′, ultralow tan δ and high Ebd compared with the PVDF/PPy@BT composites with dissociatively dispersed PPy nanoparticles and BaTiO3 particles. The polarization and loss mechanisms of the composites were then proposed based on the morphologies and the microstructures of the composites. This work provides an alternative way to fabricate functional dielectric particles through trace functional groups inducing in situ polymerization of conductive polymers, and these particles can be used to fabricate advanced dielectric composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）