Understanding the dielectric properties and electromagnetic shielding efficiency of zirconia filled epoxy-MWCNT composites

2022 ◽  
Author(s):  
Chillu Naresh ◽  
Gandluri Parameswarreddy ◽  
Asapu Vinaya Kumar ◽  
Rengaswamy Jayaganthan ◽  
Venkatachalam Subramanian ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Interfacial Adhesion ◽  
Hybrid Composites ◽  
Mechanical Analysis ◽  
Emi Shielding ◽  
High Permittivity ◽  
Interfacial Areas ◽  
Microscopic Studies ◽  
Composite Conductivity ◽  
Polymer Density

Abstract In the present study, hybrid composites are prepared by reinforcing various concentrations of high permittivity zirconia nanofiller into epoxy/CNT compositions to test their usability in EMI shielding applications in the X and Ku bands. ZrO2 nanofiller is added in different proportions to improve absorbance shielding while maintaining the composite conductivity uniform by adding constant CNT concentration to restrict the reflectance shielding. The microscopic studies have revealed an efficient dispersion of ZrO2 nanoparticles in the CNT networks and provided a smoother surface. The presence of zirconia nanofillers increased the dielectric properties, viz. the dielectric constant (194 at 0.1 Hz) and loss tangent (1.57 at 0.1 Hz), respectively, whereas the conductivity was found to be invariantly constant. The increased permittivity of composites enhanced the shielding by absorption, while the shielding by reflection is least influenced by the addition of zirconia nanofiller. The addition of zirconia nanofillers increased the permittivity and tan delta, allowing charges to accumulate at the interfacial areas for incoming EM radiations, resulting in increased absorbance shielding. Limiting the CNT concentration in all composites to the same level resulted in the formation of conductive networks, thus resulting in uniform reflectance shielding for all the hybrid composites in the present study. The dynamic mechanical analysis showed the improvement in the storage modulus and activation energy due to the enhanced interfacial adhesion and cross-linked polymer density.

Impact of silane treatment on the dielectric properties of pineapple leaf/kenaf fiber reinforced phenolic composites

2019 ◽  
Vol 54 (7) ◽  
pp. 937-946 ◽  
Author(s):  
F Agrebi ◽  
H Hammami ◽  
M Asim ◽  
M Jawaid ◽  
A Kallel
Keyword(s):  
Dielectric Properties ◽  
Interfacial Adhesion ◽  
Hybrid Composites ◽  
Silane Treatment ◽  
Dielectric Relaxation Spectroscopy ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Pineapple Leaf Fiber ◽  
Fiber Matrix ◽  
Leaf Fiber

This work deals with the dielectric properties of silane treated pineapple leaf fiber and kenaf fiber reinforced phenolic hybrid composites. The aim of the present paper is to investigate the effect of silane treatment on the pineapple leaf fiber–kenaf fiber/matrix interfacial adhesion using the dielectric relaxation spectroscopy in the frequency range from 0.1 Hz to 1 MHz and temperature range from 50 to 180℃. Our hybrid composites were fabricated by hand lay-up method at 50% total fiber loading. All the results obtained were discussed in terms of dynamic molecular and interfacial process. Two interfacial polarizations identified as the Maxwell–Wagner–Sillars effect are observed. We note that silane treatment improved the interfacial adhesion between pineapple leaf fiber/kenaf fiber and phenolic resin and it will help to develop high performance kenaf fiber/pineapple leaf fiber reinforced polymer composites for industrial applications. In fact, as known, the silane treatment developed hydrophobic nature in pineapple leaf fiber and kenaf fiber which is very positive for fiber/matrix compatibility.

Mechanical analysis of CFRP-steel hybrid composites considering the interfacial adhesion

2017 ◽  
Author(s):  
Jinhyeok Jang ◽  
Minchang Sung ◽  
Sungjin Han ◽  
Wonbo Shim ◽  
Woong-Ryeol Yu
Keyword(s):  
Interfacial Adhesion ◽  
Hybrid Composites ◽  
Mechanical Analysis

Surface-treated short sisal fibers and halloysite nanotubes for synergistically enhanced performance of polypropylene hybrid composites

2020 ◽  
pp. 089270572094606
Author(s):  
Prakash Krishnaiah ◽  
Sivakumar Manickam ◽  
Chantara Thevy Ratnam ◽  
MS Raghu ◽  
L Parashuram ◽  
...  
Keyword(s):  
Interfacial Adhesion ◽  
Hybrid Composites ◽  
Halloysite Nanotubes ◽  
Mechanical Analysis ◽  
Mechanical And Thermal Properties ◽  
Electron Microscopic ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
Sisal Fibers

Polypropylene (PP) composites were prepared by reinforcing with suitable hybrid fillers such as short sisal fibers treated with an alkali and high-intensity ultrasound (HIU) and halloysite nanotubes (HNTs) modified with 3-aminopropyltriethoxysilane. The synergistic effect of surface-treated short sisal fibers and silane-grafted HNTs were systematically evaluated through morphological, mechanical, dynamic mechanical, and thermal characterization. Alkali and HIU treatments of short sisal fibers drastically enhanced the interaction between sisal fibers and silane-grafted HNTs, which improved the interfacial adhesion between the filler system and the PP matrix. Scanning electron microscopic images indicated the continuity and smoothness of the hybrid composite surfaces. Dynamic mechanical analysis confirmed improved interactions between the hybrid filler system and the matrix, leading to significantly enhanced storage modulus in the hybrid composites. Therefore, the interfacial adhesion between the fillers and the matrix plays a significant role in improving the mechanical, dynamic mechanical, and thermal properties of polymer composites.

Influence of filler hybridization on thermomechanical properties of hemp/silver epoxy composite

2020 ◽  
pp. 096739112097811
Author(s):  
Munjula Siva Kumar ◽  
Santosh Kumar ◽  
Krushna Gouda ◽  
Sumit Bhowmik
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Epoxy Polymer ◽  
Hybrid Composites ◽  
Conductive Filler ◽  
Weight Fraction ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Material Behavior ◽  
Good Crystallinity

The polymer composite material’s thermomechanical properties with fiber as reinforcement material have been widely studied in the last few decades. However, these fiber-based polymer composites exhibit problems such as fiber orientation, delamination, fiber defect along the length and bonding are the matter of serious concern in order to improve the thermomechanical properties and obtain isotropic material behavior. In the present investigation filler-based composite material is developed using natural hemp and high thermal conductive silver nanoparticles (SNP) and combination of dual fillers in neat epoxy polymer to investigate the synergetic influence. Among various organic natural fillers hemp filler depicts good crystallinity characteristics, so selected as a biocompatible filler along with SNP conductive filler. For enhancing their thermal conductivity and mechanical properties, hybridization of hemp filler along with silver nanoparticles are conducted. The composites samples are prepared with three different combinations such as sole SNP, sole hemp and hybrid (SNP and hemp) are prepared to understand their solo and hybrid combination. From results it is examined that, chemical treated hemp filler has to maximized its relative properties and showed, 40% weight % of silver nanoparticles composites have highest thermal conductivity 1.00 W/mK followed with hemp filler 0.55 W/mK and hybrid 0.76 W/mK composites at 7.5% of weight fraction and 47.5% of weight fraction respectively. The highest tensile strength is obtained for SNP composite 32.03 MPa and highest young’s modulus is obtained for hybrid composites. Dynamic mechanical analysis is conducted to find their respective storage modulus and glass transition temperature and that, the recorded maximum for SNP composites with 3.23 GPa and 90°C respectively. Scanning electron microscopy examinations clearly illustrated that formation of thermal conductivity chain is significant with nano and micro fillers incorporation.

Polymeric textile-based electromagnetic interference shielding materials, their synthesis, mechanism and applications – A review

2021 ◽  
pp. 152808372110370
Author(s):  
Faiza Safdar ◽  
Munir Ashraf ◽  
Amjed Javid ◽  
Kashif Iqbal
Keyword(s):  
Electromagnetic Interference ◽  
Hybrid Composites ◽  
Electronic Devices ◽  
High Tech ◽  
Emi Shielding ◽  
Materials Synthesis ◽  
Synthesis Mechanism ◽  
High Frequencies ◽  
Textile Materials ◽  
Shielding Composites

The rapid proliferation of electronic devices and their operation at high frequencies has raised the contamination of artificial electromagnetic radiations in the atmosphere to an unprecedented level that is responsible for catastrophe for ecology and electronic devices. Therefore, the lightweight and flexible electromagnetic interference (EMI) shielding materials are of vital importance for controlling the pollution generated by such high-frequency EM radiations for protecting ecology and human health as well as the other nearby devices. In this regard, polymeric textile-based shielding composites have been proved to be the best due to their unique properties such as lightweight, excellent flexibility, low density, ease of processability and ease of handling. Moreover, such composites cover range of applications from everyday use to high-tech applications. Various polymeric textiles such as fibers, yarn, woven, nonwoven, knitted, as well as their hybrid composites have been extensively manipulated physically and/or chemically to act as shielding against such harmful radiations. This review encompasses from basic concept of EMI shielding for beginner to the latest research in polymeric-based textile materials synthesis for experts, covering detailed mechanisms with schematic illustration. The review also covers the gap of materials synthesis and their application on polymeric textiles which could be used for EMI shielding applications. Furthermore, recent research regarding rendering EMI shielding properties at various stages of polymeric textile development is provided for readers with critical analysis. Lastly, the applications along with environmental compliance have also been presented for better understanding.

Effect of graphite and silicon carbide fillers on mechanical properties of PA6 polymer composites

2017 ◽  
Vol 37 (6) ◽  
pp. 547-557 ◽  
Author(s):  
Sekaran Sathees Kumar ◽  
Ganesan Kanagaraj
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Polymer Composites ◽  
Interfacial Adhesion ◽  
Hybrid Composites ◽  
Fracture Morphology ◽  
Tensile Fracture ◽  
Injection Molded ◽  
The Individual

Abstract In this paper, the combined effect of different weight percentages of silicon carbide (SiC) and graphite (Gr) reinforcement on the mechanical properties of polyamide (PA6) composite is studied. Test specimens of pure PA6, 85 wt% PA6+10 wt% SiC+5 wt% Gr and 85 wt% PA6+5 wt% SiC+10 wt% Gr are prepared using an injection molding machine. The tensile, impact, hardness, morphology and thermal properties of the injection molded composites were investigated. The obtained results showed that mechanical properties, such as tensile and impact strength and modulus of the PA6 composites, were significantly higher than the pure PA6, and hybridization with silicon carbide and graphite further enhanced the performance properties, as well as the thermal resistance of the composites. The tensile fracture morphology and the characterization of PA6 polymer composites were observed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopic methods. SEM observation of the fracture surfaces showed the fine dispersion of SiC and Gr for strong interfacial adhesion between fibers and matrix. The individual and combined reinforcing effects of silicon carbide and graphite on the mechanical properties of PA6 hybrid composites were compared and interpreted in this study. Improved mechanical properties were observed by the addition of small amount of SiC and Gr concurrently reinforced with the pure PA6. Finally, thermogravimetric analysis showed that the heat resistance of the composites tended to increase with increasing silicon carbide and graphite content simultaneously.

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