Abstract Hybrid organic/inorganic electromagnetic absorbing materials (EMAMs) based on polyaniline (PANI) and magnetite (Fe 3 O 4 ) fillers dispersed in epoxy resin matrix were successfully prepared for electromagnetic applications. The effects of PANI and Fe 3 O 4 loading on permittivity, permeability and microwave absorption properties were studied. The structure and the morphology of the elaborated composites were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electromagnetic properties and absorbing behaviors were performed over frequency range of 12.4–18 GHz (Ku-band). The results show that synthesis parameters such as amount and particle size of PANI and used Fe 3 O 4 affect significantly the morphology, the conductivity, and the microwave absorption properties of the final materials. It was revealed that the electromagnetic parameters were higher in hybrid PANI/magnetite/epoxy resin than in dielectric PANI/epoxy resin composites. The permittivity and the permeability parameters increased to high values with the rate of fillers in the composite and remained constant with the frequency. A minimum reflection coefficient (RC) of −42 dB was observed at 16.3 GHz with a thickness around 1 mm for composites containing 15% of PANI and 10% of Fe 3 O 4 ( ɛ ′ = 10) and −37.4 dB at 14.85 GHz for the composite of 15% of PANI and 25% of Fe 3 O 4 ( ɛ ′ = 17) . However, a composite made with only 20% of PANI ( ɛ ′ = 8.5) showed a minimum reflection coefficient of −11 dB at 18 GHz with the same thickness. The possibility to modulate the electromagnetic properties of the composite materials is of a great interest to fabricate microwave absorbing and electromagnetic shielding materials with high performances.
Composites based on conductive organic/inorganic fillers dispersed in insulating matrix have been widely investigated because of their widespread applications such as electromagnetic shielding, electrostatic discharge, and sensors. In this context, novel composite materials based on epoxy resin matrix charged with polyaniline (PANI)-doped para-toluene sulfonic acid were elaborated. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were used to check the ...
Nanocomposites PPy/NanoG and PPy/Ni/NanoG were prepared via in situ polymerization of pyrrole in the presence of NanoG and nickel-coated graphite nanosheet (Ni/NanoG), respectively. The morphologies and nanostructures of NanoG, Ni/NanoG, PPy, PPy/NanoG and PPy/Ni/NanoG were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transmission infrared (FTIR) and X-ray diffraction analysis (XRD). Results show that most of PPy chains disperse on NanoG and ...
In this paper, we propose a multilayer nanostructured composite for broadband shielding applications. Layers disposal, electrical parameters, and thicknesses are optimized through a winning particle optimization algorithm to achieve the minimization of the transmitted waves. The structures are simulated by including the forward/backward scattering matrix formalism in the optimization code. The adopted algorithm is the recently introduced winning particle optimization. Manufacturing of the compos...
Last. Youliang Cheng(NPU: Northwestern Polytechnical University)H-Index: 5
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Abstract The design of double-layer structure could improve the absorbing properties of electromagnetic (EM) wave absorbing composites. Doping of rare metal (RM) could enhance the EM wave absorbing capability of the multi-walled carbon nanotubes (MWCNTs). In this paper, the polymer matrix composites with the different RM-doped MWCNTs and the pure MWCNTs as the absorber in the first and second layer respectively was fabricated (4 mm in thickness). The EM wave absorbing properties of these composi...
Last. Linjiang Shen(Nanjing Tech University)H-Index: 8
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Abstract The magnetic Fe3O4 nanoparticles with average diameter of about 10nm were prepared by the hydrothermal method. The Fe3O4/polyaniline nanocomposites were synthesized via reversed micelle method by using Fe3O4, camphorsulfonic acid (CSA) and ammonium peroxydisulfate (APS) as raw material, dopant and surfactant, and oxidant, respectively. The sample was characterized by XRD, UV-Vis and FT-IR. The spectra show that PANI was synthesized by chemical oxidation polymerization, while combined wi...
Last. Mario Marchetti(Sapienza University of Rome)H-Index: 27
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Abstract Microwave shielding and absorbing structures are proposed using composite materials consisting in epoxy-resin and carbon nanopowders fillers up to 10% weight concentration. Characterization in terms of dielectric parameters is performed and discussed and such data are used to optimize the modeling of multilayer electromagnetic absorber by means of in-house built Winning particle optimization algorithm. Experimental validation of mathematical simulations is then performed.
The present paper deals with the synthesis of conducting ferromagnetic polyaniline–CoFe2O4 (PC) nanocomposites via one-step chemical oxidative polymerization of aniline in the presence of CoFe2O4 nanoparticles (30–40 nm). These nanocomposites of PC have been characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). Extended thermal an...
Polyaniline (PANI)-doped benzene sulfonic acid (BSA) with moderate conductivity and high-dielectric properties affects the characteristics of its composites when its loading was below 15%. In addition, heating rate and curing temperature influenced the electrical properties of PANI, which affect composite properties as it was cured without catalyst. Moreover, dielectric, electromagnetic, thermomechanical behaviors and curing parameters were also affected by increasing PANI in matrix.
In this paper, we present the design of nanostructured multilayer absorbers, carried out with the aid of a genetic algorithm (GA). Waveguide measurements are performed to recover the dielectric properties of micrographite single-walled carbon nanotube, micrographite walled carbon nanotube, carbon nanofiber, and fullerene-based composite materials. Conductive fillers are uniformly dispersed in an epoxy resin at different weight percentages (1, 3, 5 wt.%). The electromagnetic (EM) analysis is perf...
Abstract Cobalt oxides/carbon fibers (CoO x /CFs) composites were synthesized by thermal oxidation of cobalt coated carbon fibers (Co/CFs). The scanning electron microscopy images and X-ray diffraction pattern indicate that the layers are about 0.7 μm and composed of Co 3 O 4 and CoO (CoO x ), the preferred condition for preparation of CoO x /CFs composites is to anneal Co/CFs precursors at 350 °C for 3 h in air. The coercivity, saturation magnetization and residual magnetization of the CoO x /C...
Abstract null null The gadolinium substituted cobalt ferrite (CoFe1.9Gd0.1O4) nanoparticles and CoFe1.9Gd0.1O4/Polyaniline (PANI) microwave absorber were synthesized by sol-gel auto combustion technique using lemon juice and in-situ polymerization method respectively. X-ray patterns confirmed the formation of single phase cubic structure. The crystallite size of the synthesized CoFe1.9Gd0.1O4 nanoparticles are within the range of 15–68 nm. The saturation magnetization of CoFe1.9Gd0.1O4 ferrite/P...
Abstract In the current research, a novel nanocomposite as microwaves (MW) protector was prepared by fillers including; electric conductive materials (ECM) of graphitic carbon nitrite (g-C3N4), graphene oxide (GO) and polyaniline (PANI) by specific heat program, Hammers and interfacial polymerization routs. Superdielectric material of La1.8Sr0.2NiO4 was prepared using semi-wet sol-gel procedure and magnetic materials of the Mx+yFe9x-y+3O15x+4 (0⩽x, y⩽1) (M= Sr, Mn, Fe), (x = 0, y = 0, Fe3O4 (mag...
#2Pei-Yi Wong(UKM: National University of Malaysia)
Last. Sook Wai Phang(Tunku Abdul Rahman University College)H-Index: 12
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This study investigates the microwave absorption properties of polyaniline (PAni) with varying carbonaceous material, CM (Fullerene,C60) contents. PAni nanocomposites were prepared with varying contents of C60 ranging from 5 to 40% through a chemical oxidation method by using carboxylic acid as the dopant. The functional groups of PAni nanocomposites were validated by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet–visible (UV–Vis) Spectroscopy analyses. The surface morphology of ...
In this work, a new highly water-soluble copolymer of polyacrylic acid with polyaniline is introduced. Acrylic acid was polymerized via the Reversible Addition Fragmentation Chain Transfer method (RAFT) in the presence of an initiator and the obtained polyacrylic acid was copolymerized with aniline at room temperature. As the main achievements of this work, the resulting block copolymer with nanosized structure revealed favorable solubility in polar solvents, as well as excellent antibacterial a...
#2N. Kalaivasan(Thanthai Periyar Government Institute of Technology)H-Index: 3
Last. S. Sudarsan(C. Abdul Hakeem College of Engineering & Technology)H-Index: 2
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Abstract The objective of the present investigation is to fabricate the gold anchor polyaniline (PANI) based nanocomposites which is prepared using itaconic acid (IA) with Fe3O4 by the simple polymerization reaction. The developed multi responsive antibacterial magnetic polymeric composite is represented as Au@PANI–IA– Fe3O4. Further, the chemical structure, thermal and magnetic properties such as FT-IR, TGA/DTA, and VSM analysis are studied. The TEM and SEM/EDX are used to find the shape and co...
Last. Mao-Sheng Cao(BIT: Beijing Institute of Technology)H-Index: 88
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AbstractIn this study, we report two-dimensional WS2 nanosheets successfully synthesized by simple hydrothermal method. The obtained WS2 nanosheets are very promising as electromagnetic wave absorb...
Last. Xuan Zhao(Beijing Jiaotong University)H-Index: 7
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The modification of flake-like porous Fe3O4@C core–shell nanorods having 25–50 nm pore diameter with polyaniline nanosheets is described. The microwave absorption properties of Fe3O4@C, polyaniline, and Fe3O4@C/polyaniline composite are analyzed according to their electromagnetic parameters. The analysis of the electromagnetic parameters indicates that dielectric loss, which, along with the impedance matching, is improved by the addition of polyaniline, is the main factor governing the microwave...