Journal ArticleDOI
Tunable electromagnetic shielding properties of conductive poly(vinylidene fluoride)/Ni chain composite films with negative permittivity
Biao Zhao,Chul B. Park +1 more
Reads0
Chats0
TLDR
In this paper, a detailed investigation of the dielectric permittivity, electrical conductivity, and electromagnetic interference (EMI) shielding properties of polyvinylidene fluoride (PVDF)/Ni-chain composites with different Ni contents using the solution processing and compression molding method was made.Abstract:
In this study, we fabricated various poly(vinylidene fluoride) (PVDF)/Ni-chain composites with different Ni contents using the solution processing and compression molding method. We made a detailed investigation of the dielectric permittivity, electrical conductivity, and electromagnetic interference (EMI) shielding properties of the PVDF/Ni-chain composites. With a high concentration of Ni (6 wt% and 12 wt%), the dielectric permittivity had negative values, which were due to the formation of conductive networks in the PVDF matrix. We also discussed the generation of negative permittivity, and concluded that PVDF/Ni-chains could be potentially used as “natural metamaterials.” Upon increasing the Ni content, their electrical conductivity and EMI shielding properties were improved. Moreover, the EMI shielding properties were closely related to the composite films' thicknesses. The average EMI properties of the PVDF/6 wt%-Ni composite films at thicknesses of 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm were 15.4 dB, 24.7 dB, 30.3 dB, and 35.4 dB, respectively. The shielding mechanism was mainly governed by absorption. We also proposed the possibility of a dissipation mechanism in the PVDF/Ni-chain composite, which is related to Ni's dual loss mechanism and unique chain-like structure that formed three-dimensional nets in the PVDF matrix.read more
Citations
More filters
Journal ArticleDOI
Promising Ti3C2Tx MXene/Ni Chain Hybrid with Excellent Electromagnetic Wave Absorption and Shielding Capacity.
Luyang Liang,Gaojie Han,Yang Li,Biao Zhao,Bing Zhou,Yuezhan Feng,Jianmin Ma,Yaming Wang,Rui Zhang,Chuntai Liu +9 more
TL;DR: Mechanism analysis reveals that the excellent EM wave absorption and shielding performances of the hybrid are contributed to the synergistic effect of conductive MXene and magnetic Ni chains, by which, the dielectric properties and electromagnetic loss can be easily controlled to obtain appropriate impedance matching conditions and good EM wave dissipation ability.
Journal ArticleDOI
Designed fabrication of reduced graphene oxides/Ni hybrids for effective electromagnetic absorption and shielding
TL;DR: In this paper, a reduced graphene oxide (rGO)/Ni hybrid with different mass ratio was synthesized in order to tune the microwave absorption together with the electromagnetic shielding performance, and an optimal reflection loss value of −39.03 dB at 13 GHz was achieved for the composite with rGO/Ni ratio of 1:1.
Journal ArticleDOI
Tunable and weakly negative permittivity in carbon/silicon nitride composites with different carbonizing temperatures
Chuanbing Cheng,Chuanbing Cheng,Chuanbing Cheng,Runhua Fan,Zhongyang Wang,Qian Shao,Xingkui Guo,Peitao Xie,Yansheng Yin,Yuliang Zhang,Liqiong An,Yanhua Lei,Jong Eun Ryu,Akash Shankar,Zhanhu Guo +14 more
TL;DR: In this paper, a random metamaterial, carbon/silicon nitride (C/Si3N4) composite, using a feasible impregnation-pyrolysis method was fabricated, and the microstructure and dielectric property of the composites with different heat treatment temperatures and carbon contents were investigated.
Journal ArticleDOI
Co/C/Fe/C Hierarchical Flowers with Strawberry-like Surface as Surface Plasmon for Enhanced Permittivity, Permeability, and Microwave Absorption Properties
TL;DR: In this paper, surface-dependent electromagnetic properties of Co/C/Fe/C core-shell hierarchical flowers (CSHFs) were investigated at 2-18 GHz at the presence of plasmon resonance and coupling.
Journal ArticleDOI
Carbon nanospheres induced high negative permittivity in nanosilver-polydopamine metacomposites
Hongbo Gu,Xiaojiang Xu,Mengyao Dong,Mengyao Dong,Peitao Xie,Qian Shao,Runhua Fan,Chuntai Liu,Shide Wu,Renbo Wei,Zhanhu Guo +10 more
TL;DR: In this paper, a unique high negative permittivity is observed in the carbon nanosphere (CNS) supported nanosilver-polydopamine (PDA) metacomposites (called CNS-PDA/Ag).
References
More filters
Journal ArticleDOI
Composite Medium with Simultaneously Negative Permeability and Permittivity
TL;DR: A composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeability and permittivity varepsilon(eff)(omega).
Journal ArticleDOI
Extremely Low Frequency Plasmons in Metallic Mesostructures
TL;DR: A mechanism for depression of the plasma frequency into the far infrared or even GHz band is proposed: Periodic structures built of very thin wires dilute the average concentration of electrons and considerably enhance the effective electron mass through self-inductance.
Journal ArticleDOI
Electromagnetic interference shielding effectiveness of carbon materials
TL;DR: Carbon materials for electromagnetic interference (EMI) shielding are reviewed in this article, including composite materials, colloidal graphite and flexible graphite, and they include carbon filaments of submicron diameter.
Journal ArticleDOI
The effects of temperature and frequency on the dielectric properties, electromagnetic interference shielding and microwave-absorption of short carbon fiber/silica composites
TL;DR: In this paper, a dielectric spectroscopy of short carbon fiber/silica composite in the frequency range from 8.2 to 12.4 GHz at temperatures between 30 and 600°C has been performed.
Journal ArticleDOI
Electromagnetic interference shielding mechanisms of CNT/polymer composites
TL;DR: In this article, the electromagnetic interference (EMI) shielding mechanisms of multi-walled carbon nanotube (MWCNT)/polymer composites were analyzed experimentally and theoretically.