Lightweight flexible carbon nanotube/polyaniline films with outstanding EMI shielding properties

2017 ◽  
Vol 5 (34) ◽  
pp. 8694-8698 ◽  
Author(s):  
Hui Li ◽  
Xuehong Lu ◽  
Du Yuan ◽  
Jiaotong Sun ◽  
Fuat Erden ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Polyaniline Films ◽  
Shielding Properties

Flexible and highly conductive CNT/PANI films were developed for EMI shielding applications, which exhibited the highest specific shielding effectiveness among those reported.

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

EMI Shielding Properties of Polymer Blend with the Inclusion of Graphene Nano Platelets

2021 ◽  
Vol 875 ◽  
pp. 160-167
Author(s):  
Muhammad Fayzan Shakir ◽  
Asra Tariq
Keyword(s):  
Electromagnetic Interference ◽  
Coaxial Cable ◽  
Network Analyzer ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electrically Conductive ◽  
Emi Shielding Effectiveness ◽  
Increasing Trend ◽  
Shielding Properties ◽  
Basic Prediction

Polymer nano composites based on poly vinyl chloride matrix were fabricated using polyaniline (PANI) and graphene nano platelets (GNP) as electrically conductive nano filler for the application of electromagnetic interference (EMI) shielding. DC conductivity was first evaluated by using cyclic voltammetry and found an increasing trend of electrical conductivity as PANI and GNP was added in PVC matrix that confirms the formation of electrically conductive network structure. Dielectric properties like dielectric constant, dielectric loss and AC conductivity were evaluated in frequency range of 100 Hz to 3 MHz that gives basic prediction for EMI shielding effectiveness. Vector Network Analyzer (VNA) was used to assess EMI shielding properties using coaxial cable method in 11GHz to 20GHz range and it was found that a maximum of 29 dB shielding was archived with the incorporation of 15 wt% of PANI in PVC. This value increased to 56 dB as 5 wt% GNP added in PVC/PANI 15 wt% blend. Interaction of matrix with filler, nature of filler and dispersion of filler in matrix are the key parameters for achieving high shielding effectiveness.

scholarly journals An anisotropic layer-by-layer carbon nanotube/boron nitride/rubber composite and its application in electromagnetic shielding

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7782-7791 ◽  
Author(s):  
Yanhu Zhan ◽  
Emanuele Lago ◽  
Chiara Santillo ◽  
Antonio Esaú Del Río Castillo ◽  
Shuai Hao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Boron Nitride ◽  
Layer By Layer ◽  
Shielding Effectiveness ◽  
Anisotropic Layer ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
Rubber Composite

A carbon nanotube/boron nitride/rubber composite with anisotropic electrical conductivity exhibits an EMI shielding effectiveness of 22.41 dB mm−1 and a thermal conductivity equal to 0.25 W m−1 K−1.

scholarly journals Electrical Properties and Electromagnetic Interference Shielding Effectiveness of Interlayered Systems Composed by Carbon Nanotube Filled Carbon Nanofiber Mats and Polymer Composites

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 238 ◽  
Author(s):  
Claudia Angélica Ramírez-Herrera ◽  
Homero Gonzalez ◽  
Felipe de la Torre ◽  
Laura Benitez ◽  
José Gerardo Cabañas-Moreno ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Carbon Nanofiber ◽  
Layered Composite ◽  
Multiwall Carbon Nanotube ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Nanofiber Composite

The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new composite materials. This study focuses on the development of multiwall carbon nanotube (MWCNT) filled polypropylene composites and carbon nanofiber composite mats. The developed systems were then used to prepare interlayered composites that exhibited improved electrical conductivity and electromagnetic interference (EMI) shielding efficiency. MWCNT-carbon nanofiber composite mats were developed by centrifugally spinning mixtures of MWCNT suspended in aqueous poly(vinyl alcohol) solutions. The developed nanofibers were then dehydrated under sulfuric acid vapors and then heat treated. Interlayered samples were fabricated using a nanoreinforced polypropylene composite as a matrix and then filled with carbon fiber composite mats. The in-plane and through-plane electrical conductivity of an eight-layered flexible carbon composite (0.65 mm thick) were shown to be 6.1 and 3.0 × 10−2 S·cm−1, respectively. The EMI shielding effectiveness at 900 MHz increased from 17 dB for the one-layered composite to 52 dB for the eight-layered composite. It was found that the reflection of the electromagnetic waves was the dominating mechanism for EMI shielding in the developed materials. This study opens up new opportunities for the fabrication of novel lightweight materials that are to be used in communication systems.

scholarly journals Electromagnetic Interference Shielding Behavior of Magnetic Carbon Fibers Prepared by Electroless FeCoNi-Plating

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3774
Author(s):  
Yoon-Ji Yim ◽  
Jae Jun Lee ◽  
Alexandre Tugirumubano ◽  
Sun Ho Go ◽  
Hong Gun Kim ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
X Ray Diffraction ◽  
Emi Shielding Effectiveness ◽  
Plating Method ◽  
Magnetic Metal ◽  
Shielding Properties ◽  
Metal Layers

In this study, soft magnetic metal was coated on carbon fibers (CFs) using an electroless FeCoNi-plating method to enhance the electromagnetic interference (EMI) shielding properties of CFs. Scanning electron microscopy, X-ray diffraction, and a vibrating sample magnetometer were employed to determine the morphologies, structural properties, and magnetic properties of the FeCoNi-CFs, respectively. The EMI shielding behavior of the FeCoNi-CFs was investigated in the frequency range of 300 kHz to 3 GHz through vector network analysis. The EMI shielding properties of the FeCoNi-CFs were significantly enhanced compared with those of the as-received CFs. The highest EMI shielding effectiveness of the 60-FeCoNi-CFs was approximately 69.4 dB at 1.5 GHz. The saturation magnetization and coercivity of the 60-FeCoNi-CFs were approximately 103.2 emu/g and 46.3 Oe, respectively. This indicates that the presence of FeCoNi layers on CFs can lead to good EMI shielding due to the EMI adsorption behavior of the magnetic metal layers.

scholarly journals Improved Electromagnetic Interference Shielding Properties Through the Use of Segregate Carbon Nanotube Networks

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1395 ◽  
Author(s):  
Sung-Hoon Park ◽  
Ji-Hwan Ha
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Electromagnetic Interference ◽  
Silica Particles ◽  
Excluded Volume ◽  
Emi Shielding ◽  
Excluded Volume Effects ◽  
Content Ratio ◽  
Shielding Properties ◽  
Micro Silica

We report the enhanced electromagnetic interference (EMI) shielding properties of hybrid carbon nanotube (CNT) composites consisting of more than two kinds of fillers through the use of segregate conducting networks. An excluded volume was created by micro-sized silica particles that concentrate the CNT network, resulting in improved electrical conductivity and microwave properties. To achieve the optimal dispersion of CNTs and silica particles, high shear force was applied to the pre-cured composite mixture via three-roll milling. Depending on the micro-silica content ratio, we observed improved electrical conductivity and EMI shielding properties. For a quantitative comparison to observe the excluded-volume effects, a CNT composite without micro-silica was measured in parallel with the other sample.

scholarly journals EMI Shielding Nanocomposite Laminates with High Temperature Resistance, Hydrophobicity and Anticorrosion Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3155
Author(s):  
Shaojun Wu ◽  
Zhiyong Zhao ◽  
Hongliang Hou ◽  
Xiang Xue
Keyword(s):  
Carbon Nanotube ◽  
High Performance ◽  
Carbon Nanofiber ◽  
Low Cost ◽  
Electric Heating ◽  
Decomposition Temperature ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Initial Decomposition Temperature ◽  
Carbon Nanotube Film

High-performance multifunctional EMI shielding composite fabricated by low-cost method is increasingly required. Herein, novel EMI shielding nanocomposite laminates, consisting of composite prepreg of carbon fiber/epoxy resin/carbon nanotube film, were manufactured by facile electric heating of carbon nanotube film. The results indicated that composite with excellent specific shielding effectiveness of 0.07 dB/μm, 47 dB cm3/g and metamaterial properties can be designed by composite prepreg, and the primary shielding mechanism of it was reflection loss, along with interface polarization loss and conductive loss, which was superior to lots of shielding materials including carbon nanotube-based, carbon black-based, carbon nanofiber-based and graphene-based materials reported previously. Meanwhile, highly required excellent properties, including the thermostability with initial decomposition temperature up to 300 °C, hydrophobicity over contact angle of 115°, corrosion resistance of the composite with metal-free modification, and function as structural laminate compared with previous studies were demonstrated, which suggested tremendous potentials of the multifunctional EMI shielding composites in harsh environment.

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