scispace - formally typeset
Search or ask a question
Author

Anuj Shukla

Bio: Anuj Shukla is an academic researcher. The author has contributed to research in topics: Nanoparticle & Reflection loss. The author has an hindex of 7, co-authored 10 publications receiving 456 citations.

Papers
More filters
Journal ArticleDOI
01 May 2012-Carbon
TL;DR: In this paper, reduced graphene oxide (RGO) with a layered and porous structure was synthesized by thermal exfoliation of graphite oxide using Fourier transform infrared and Raman spectroscopies, X-ray diffraction and scanning electron microscopy.

383 citations

Journal ArticleDOI
TL;DR: In this article, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and spectrofluorometer techniques were used to obtain the crystallite size and size distribution from powder samples using the FW((1/5)/(4/5))M method.

34 citations

Journal ArticleDOI
TL;DR: In this article, the effect of percentage loading of nanosize carbon black (CB) on DC conductivity, dielectric and microwave absorption properties and electromagnetic Shielding Effectiveness (SE) of silicone rubber composites is studied.
Abstract: In this paper, studies on broadband microwave absorption and electromagnetic shielding effectiveness are reported in flexible rubber composites with low filler content of nanosize conducting carbon over 8–18 GHz frequency range of electromagnetic spectrum. Rubber based composites are prepared by loading of 1–15 wt% nanosize conducting Carbon Black (CB) in silicone rubber matrix. Effect of percentage loading of nanosize CB on DC conductivity, dielectric & microwave absorption properties and electromagnetic Shielding Effectiveness (SE) of silicone rubber composites is studied. The percolation threshold is achieved at low concentration (3 wt%) of CB in composites. The observed complex permittivity values revealed that composites with concentration of 5wt% CB can provide more than 90% microwave absorption (Reflection Loss > −10 dB) over 8–18 GHz at composite thickness of 1.9–2.7 mm. Further, composites with concentration of 15 wt% of CB shows −40 dB SE over the broad frequency range 8–18 GHz at thickness 2.8 mm. The effect of composite thickness on microwave absorption properties and shielding effectiveness is also analyzed. Thus, the prepared rubber composites with suitable concentration of nanosize CB as filler may be used as microwave absorber in stealth applications as well as for EMI shielding of electronic equipments in various civilian and military areas.

19 citations

Journal ArticleDOI
TL;DR: In this article, the microwave absorption properties of core-shell nanostructures have been studied by making their composites in nitrile butadiene rubber, and it has been shown that the frequency of maximum return loss can be tuned through variation of composition and thickness of composite layer.
Abstract: Core–shell iron nanoparticles have been synthesized by pyrolysis of nanocomposite of oxides of iron–tin (Fe–Sn). The core–shell nanoparticles of phase pure iron in carbonaceous shell are formed only at very low concentration of tin (0.0011 mol) in the nanocomposite sample. From different studies viz. X-ray diffraction, high-resolution transmission electron microscopy, atomic force microscopy, and Raman spectroscopy, it has been established that core–shell nanostructures have been formed with Fe as core and amorphous carbon as the shell. The heating of nanocomposite at different temperatures up to 900 °C revealed very interesting dynamics of formation of core–shell structure wherein above 650 °C the iron carbide phase decomposes and carbon atoms move out to form an amorphous shell around iron nanoparticles. This process of formation of core–shell structures is quite different from conventional way wherein synthesis of core material precedes formation of shell in two different steps. The microwave absorption properties of core–shell nanoparticles have been studied by making their composites in nitrile butadiene rubber. Reflection loss simulation studies show high values in the X and Ku bands of microwave region. The frequency of maximum return loss can be tuned through variation of composition and thickness of composite layer.

18 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The broadband and tunable high-performance microwave absorption properties of an ultralight and highly compressible graphene foam (GF) are investigated and it is shown that via physical compression, the microwave absorption performance can be tuned.
Abstract: The broadband and tunable high-performance microwave absorption properties of an ultralight and highly compressible graphene foam (GF) are investigated. Simply via physical compression, the microwave absorption performance can be tuned. The qualified bandwidth coverage of 93.8% (60.5 GHz/64.5 GHz) is achieved for the GF under 90% compressive strain (1.0 mm thickness). This mainly because of the 3D conductive network.

1,533 citations

Journal ArticleDOI
TL;DR: This review focuses on the recent development and various strategies in the preparation, microstructure, and magnetic properties of bare and surface functionalized iron oxide nanoparticles (IONPs); their corresponding biological application was also discussed.

1,143 citations

Journal ArticleDOI
TL;DR: Graphene has a unique atom-thick two-dimensional (2D) structure, high conductivity and charge mobility, huge specific surface area, excellent mechanical, thermal and electrical properties.
Abstract: Graphene has a unique atom-thick two-dimensional (2D) structure, high conductivity and charge mobility, huge specific surface area, excellent mechanical, thermal and electrical properties. Thus, it has been regarded as an important component for functional materials, especially for developing a variety of catalysts. In this review, we summarize the recent advancements in synthesizing graphene based new catalysts, and their applications in organic synthesis, sensors, environmental protection and energy related systems.

685 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reported a facile solvothermal route to synthesize laminated magnetic graphene and showed that there have significant changes in the electromagnetic properties of magnetic graphene when compared with pure graphene.
Abstract: Graphene is highly desirable as an electromagnetic wave absorber because of its high dielectric loss and low density. Nevertheless, pure graphene is found to be non-magnetic and contributes to microwave energy absorption mostly because of its dielectric loss, and the electromagnetic parameters of pure graphene, which are out of balance, result in a bad impedance matching characteristic. In this paper, we report a facile solvothermal route to synthesize laminated magnetic graphene. The results show that there have been significant changes in the electromagnetic properties of magnetic graphene when compared with pure graphene. Especially the dielectric Cole–Cole semicircle suggests that there are Debye relaxation processes in the laminated magnetic graphene, which prove beneficial to enhance the dielectric loss. We also proposed an electromagnetic complementary theory to explain how laminated magnetic graphene, with the combined advantages of graphene and magnetic particles, helps to improve the standard of impedance matching for electromagnetic wave absorbing materials. Besides, microwave absorption properties indicate that the reflection loss of the as-prepared composite is below −10 dB (90% absorption) at 10.4–13.2 GHz with a coating layer thickness of 2.0 mm. This further confirms that the nanoscale surface modification of magnetic particles on graphene makes graphene-based composites have a certain research value in electromagnetic wave absorption.

663 citations