scholarly journals Comparison of Experimental and Modeled EMI Shielding Properties of Periodic Porous xGNP/PLA Composites

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1233 ◽  
Author(s):  
Avi Bregman ◽  
Eric Michielssen ◽  
Alan Taub
Keyword(s):  
Aspect Ratio ◽  
Polymer Composites ◽  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Composite Structures ◽  
Electromagnetic Properties ◽  
Poly Lactic Acid ◽  
Throughput Optimization ◽  
Emi Shielding ◽  
Shielding Properties

Microwave absorbing materials, particularly ones that can achieve high electromagnetic interference (EMI) absorption while minimizing weight and thickness are in high demand for many applications. Herein we present an approach that relies on the introduction of periodically placed air-filled pores into polymer composites in order to reduce material requirements and maximize microwave absorption. In this study, graphene nano platelet (xGNP)/poly-lactic acid (PLA) composites with different aspect ratio fillers were characterized and their complex electromagnetic properties were extracted. Using these materials, we fabricated non-perfect electrical conductor (PEC) backed, porous composites and explored the effect of filler aspect ratio and pore geometry on EMI shielding properties. Furthermore, we developed and experimentally verified a computational model that allows for rigorous, high-throughput optimization of absorbers with periodic porous geometries. Finally, we extend the modeling approach to explore the effect of pore addition on PEC-backed composites. Our composite structures demonstrated decreased fractions of reflected power and increased fractions of absorbed power over the majority of the X Band due to the addition of periodically arranged cylindrical pores. Furthermore, we showed that for xGNP/PLA composite material, reflection loss can be increased by as much as 13 dB through the addition of spherical pores. The ability to adjust shielding properties through the fabrication of polymer composites with periodically arranged pores opens new strategies for the modeling and development of new microwave absorption materials.

scholarly journals Dependence of electromagnetic interference shielding ability of conductive polymer composite foams with hydrophobic properties on cellular structure

2020 ◽  
Vol 8 (22) ◽  
pp. 7401-7410 ◽  
Author(s):  
Biao Zhao ◽  
Ruoming Wang ◽  
Yang Li ◽  
Yumei Ren ◽  
Xiao Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Cellular Structure ◽  
Conductive Polymer ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Hydrophobic Properties ◽  
Conductive Polymer Composites ◽  
Composite Foams ◽  
Shielding Properties

The introduction of a cellular structure in conductive polymer composites is supposed to be an effective way to ameliorate the electromagnetic interference (EMI) shielding properties.

Electromagnetic Interference Shielding Properties of Carbon Nanotubes Reinforced Composites

2007 ◽  
Vol 26-28 ◽  
pp. 305-308 ◽  
Author(s):  
Tae Wan Kim ◽  
Hye Rim Lee ◽  
Sung Soo Kim ◽  
Yun Soo Lim
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Interference ◽  
Electromagnetic Properties ◽  
Chemical Vapor Deposition Method ◽  
Strip Line ◽  
Reinforced Composites ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Shielding Properties

Electromagnetic interference (EMI) shielding refers to the reflection and/or adsorption of electromagnetic radiation by materials, which acts as a shield against the penetration of the radiation through the shield. In this study, two directional carbon fibers reinforced composites with carbon nanotubes as fillers were studied for the high frequency electromagnetic properties and mechanical properties. Carbon nanotubes were prepared by a catalytic chemical vapor deposition method with ferrocene/xylene mixture. The electromagnetic insulating properties were measured by micro strip line method in this study. Electromagnetic interference shielding properties of composites were investigated in the frequency region of 0.3-6 GHz. The experimental results indicated that the EMI shielding effectiveness of carbon composite is sensitive to the existence of CNT.

Interface design of carbon filler/polymer composites for electromagnetic interference shielding

2021 ◽  
Author(s):  
Runxiao Chen ◽  
Rongrong Yu ◽  
Xiaoyuan Pei ◽  
Wei Wang ◽  
Diansen Li ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Electromagnetic Interference ◽  
Interface Design ◽  
Electrical Equipment ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Carbon Filler ◽  
Portable Electronics ◽  
Electromagnetic Pollution ◽  
Carbon Based

The extensive use of electrical equipment and portable electronics has aroused major concerns about electromagnetic pollution. Carbon-based polymer composites are widely used in the electromagnetic interference (EMI) shielding field, motivated...

Manipulating the Assembly of the CNC/RGO Composite Film for Superior Electromagnetic Interference Shielding Properties

2021 ◽  
Author(s):  
kexia Jin ◽  
Jianxiong Xing ◽  
Xinge Liu ◽  
Zehui Jiang ◽  
Shumin Yang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Cellulose Nanocrystals ◽  
Electromagnetic Interference ◽  
Practical Application ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
High Mechanical Strength ◽  
Dispersing Agent ◽  
Reduced Graphene ◽  
Shielding Properties

To achieve high mechanical strength electromagnetic interference (EMI) shielding materials for practical application, cellulose nanocrystals (CNC) as a reinforcing and dispersing agent, are intercalated into reduced graphene oxide (RGO) layers,...

Incorporating a microcellular structure into PVDF/graphene–nanoplatelet composites to tune their electrical conductivity and electromagnetic interference shielding properties

2018 ◽  
Vol 6 (38) ◽  
pp. 10292-10300 ◽  
Author(s):  
Biao Zhao ◽  
Chongxiang Zhao ◽  
Mahdi Hamidinejad ◽  
Chongda Wang ◽  
Ruosong Li ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electromagnetic Interference ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Graphene Nanoplatelet ◽  
Shielding Properties

The electrical conductivity and the EMI shielding properties could be effectively tuned by the foaming degree.

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.

Sustainable wood-based composites for microwave absorption and electromagnetic interference shielding

2020 ◽  
Vol 8 (46) ◽  
pp. 24267-24283 ◽  
Author(s):  
Ming Zhou ◽  
Weihua Gu ◽  
Gehuan Wang ◽  
Jing Zheng ◽  
Chunchuan Pei ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding

In this review, wood-based composites for efficient EMI shielding and MA are comprehensively introduced.

Cobaltosic oxide fiber/Carbon Fiber composites fabricated by hydrothermal for improved electromagnetic interference shielding properties

2019 ◽  
Vol 33 (09) ◽  
pp. 1950075
Author(s):  
Ming Gong ◽  
Qiang Li ◽  
Lin Sun ◽  
Ai-Qin Tian ◽  
Shou-Guang Sun
Keyword(s):  
Carbon Fiber ◽  
Electromagnetic Interference ◽  
Fiber Composites ◽  
Interface Strength ◽  
Carbon Fiber Composites ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Calcination Step ◽  
Cobaltosic Oxide ◽  
Shielding Properties

In this paper, a newly designed composite of magnetic nano-Co3O4 fiber coated on carbon fiber (Cf) is prepared and characterized for the electromagnetic interference (EMI) shielding properties. XRD, SEM and TEM are used to investigate the micromorphology and microstructure evolution during the preparation. By hydrothermal method, the flowerlike clusters of single crystal flake-Co(OH)2 are first obtained on Cf. The firstly prepared Co(OH)2 sheets then turn into Co3O4 fibers during the next calcination step. The continuous and loose coating of magnetic Co3O4 nanofibers is finally obtained on the Cf. The loose coating is in proportion to the weight loss, and the wirelike Co3O4 is good for the interface strength for the Cf composite preparation. Based on the above work, the loose magnetic fibers coating on the Cf could be a feasible composite structure for the EMI composite materials integrated with absorbing and reflecting.

Graphene nanohybrids: excellent electromagnetic properties for the absorbing and shielding of electromagnetic waves

2018 ◽  
Vol 6 (17) ◽  
pp. 4586-4602 ◽  
Author(s):  
Maosheng Cao ◽  
Chen Han ◽  
Xixi Wang ◽  
Min Zhang ◽  
Yanlan Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Charge Transport ◽  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Electromagnetic Properties ◽  
Response Mechanism ◽  
Microwave Response ◽  
Electromagnetic Interference Shielding

The microwave absorption, electromagnetic interference shielding, and microwave response mechanism of graphene hybrids are highlighted, including relaxation, charge transport, magnetic resonance,etc.

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