Electrical percolation behavior and electromagnetic shielding effectiveness of polyimide nanocomposites filled with carbon nanofibers

2014 ◽  
Vol 131 (24) ◽  
pp. n/a-n/a ◽  
Author(s):  
Lalatendu Nayak ◽  
Tapan K. Chaki ◽  
Dipak Khastgir
Keyword(s):  
Carbon Nanofibers ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Electrical Percolation ◽  
Percolation Behavior ◽  
Electromagnetic Shielding Effectiveness

scholarly journals Analyses of the mechanical, electrical and electromagnetic shielding properties of thermoplastic composites doped with conductive nanofillers

2018 ◽  
Vol 52 (11) ◽  
pp. 1423-1432 ◽  
Author(s):  
Ali Can Yilmaz ◽  
Mustafa Sabri Ozen ◽  
Erhan Sancak ◽  
Ramazan Erdem ◽  
Ozlem Erdem ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Polyvinylidene Fluoride ◽  
Network Formation ◽  
Substantial Reduction ◽  
Microscopic Analysis ◽  
Electromagnetic Shielding ◽  
Thermoplastic Composites ◽  
Shielding Effectiveness ◽  
Electron Microscopic ◽  
Electromagnetic Shielding Effectiveness

The purpose of this study is to observe effect of incorporating vapor-grown carbon nanofibers with various amounts in polyvinylidene fluoride matrix in terms of mechanical strength and electromagnetic shielding effectiveness. Thermoplastic conductive nanocomposites were prepared by heat-pressed compression molding. Vapor-grown carbon nanofibers were utilized at various weight ratios (1 wt.%, 3 wt.%, 5 wt.%, and 8 wt.%) as conductive and reinforcing materials. Polyvinylidene fluoride was used as a thermoplastic polymer matrix. Scanning electron microscopic analysis was conducted in order to characterize the morphology and structural properties of the nanocomposites and results revealed well dispersion of carbon nanofibers within the matrix for all concentrations. Mechanical characteristics were investigated according to standards. Findings proved that overall increments of 16%, 37.5%, and 56% were achieved in terms of tensile strength, elasticity modulus, and impact energy, respectively, where a total reduction of 44.8% was observed in terms of elongation for 8 wt.% vapor-grown nanofiber matrix compared to that of 0 wt.%. Electromagnetic shielding effectivenesses of the nanocomposites were determined by standard protocol using coaxial transmission line measurement technique in the frequency range of 15–3000 MHz. It was observed that resistance, sheet resistance, and resistivity of nanocomposites depicted substantial reduction with the increment in nanofiber content. Nevertheless, it was observed that nanofiber content, dispersion, and network formation within the composites were highly influent on the electromagnetic shielding effectiveness performance of the structures.

scholarly journals Electromagnetic wave shielding and mechanical properties of vapor-grown carbon nanofiber/polyvinylidene fluoride composite fibers

2020 ◽  
Vol 15 ◽  
pp. 155892502098595
Author(s):  
Metin Yuksek
Keyword(s):  
Tensile Strength ◽  
Carbon Nanofibers ◽  
Polyvinylidene Fluoride ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Shielding Effectiveness ◽  
Composite Fibers ◽  
Conductive Composite ◽  
Electromagnetic Shielding Effectiveness

The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new conductive composite fibers. This study focuses on the development of Vapor-grown carbon nanofibers (VGCNFs) filled Polyvinylidene Fluoride (PVDF) composite fibers. Polyvinylidene fluoride (PVDF) reinforced with (1, 3, 5, and 8 wt.%) carbon nanofibers were produced as a masterbatch. The production of PVDF and PVDF/CNF composite fibers have been done successfully by using melt spinning processing technique. Conductive woven fabrics were produced with composite fibers on handloom machines to measure electromagnetic interference (EMI) shielding efficiency. Tensile strength of fibers increased with increase in CNF loading up to 3%. The tensile strength displayed a decrease of 5% and 8% CNF loading. Electromagnetic shielding effectiveness (EMSE) of woven fabrics with composite fibers were tested by using the coaxial transmission line method for planar materials standard that is based on ASTM D 4935-10. The electromagnetic shielding effectiveness of woven fabric which is consist of conductive composite fibers were increased with increasing CNFs loading and amount of fabric layers. It can be seen that the woven fabrics displayed between 2–10 dB and 2–4 dB EMSE values in the 15–600 MHz and 600–3000 MHz-frequency range, respectively. Nevertheless, it was observed that conductive filler content, dispersion, and network formation within the composite fibers were highly influent on the electromagnetic shielding effectiveness performance of the structures.

Analyses on the Manufacture and Physical Properties of Electromagnetic Shielding/ Far Infrared Ray Nonwoven

2010 ◽  
Vol 97-101 ◽  
pp. 1790-1793
Author(s):  
Jia Horng Lin ◽  
Yu Tien Huang ◽  
Chin Mei Lin ◽  
Yi Chang Yang ◽  
Chien Teng Hsieh ◽  
...  
Keyword(s):  
Physical Properties ◽  
Far Infrared ◽  
Electromagnetic Shielding ◽  
Breaking Force ◽  
Shielding Effectiveness ◽  
Machine Direction ◽  
Tear Strength ◽  
Burst Strength ◽  
Far Infrared Ray ◽  
Electromagnetic Shielding Effectiveness

According to the results, when low melting polyester fiber increased to be 20%, the electromagnetic shielding/ far infrared ray nonwoven obtained the optimum burst strength, maximum breaking force and maximum tear strength, and they were as follows: burst strength was 4.2 kgf/cm2; maximum breaking force was 153.59 N in the cross machine direction and 70.80 N in the machine direction; maximum tear strength was 215.77 N in cross machine direction and 117.07 N in machine direction; and optimum electromagnetic shielding effectiveness (EMSE) was 45 dB.

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