High performance X-band electromagnetic shields based on methyl-orange assisted polyaniline-silver core-shell nanocomposites

ABSTRACT

Present communication explores the remarkably high shielding effectiveness of about 70 dB, exhibited by advanced core-shell-type polyaniline-silver nanosheets (PAg) in X-band (4–12 GHz), synthesized from methyl-orange assisted chemical oxidative polymerization route. The high-resolution tunneling microscope reveals the formation of PAg nanogranules and nanosheets with different silver nitrate concentrations (0.3 M and 0.6 M, respectively). The enhanced shielding effectiveness of nanosheets compared to other samples is attributed quite sensitively to its high conducting value, which is predominantly determined by the concentration of silver nitrate used during synthesis. The structural characterizations using high-resolution X-ray diffraction technique reveals the enhanced crystallinity of PAg samples, which significantly contributes to the enhancement of their conductivities. The dc charge transport study in temperature range 77 K-300 K reveals that the PAg samples exhibit metallic behavior, whereas the polyaniline samples show semi-conducting nature. This can be ascribed to the presence of silver content in nanocomposites, which results in higher conductivities of the PAg samples. This study opens a new window for shielding of electromagnetic pollution by advanced core-shell morphologies at commercial scale.

KEYWORDS:

• Core-shell nanostructures
• X-band
• shielding effectiveness
• charge transport

Acknowledgements

This work is financially assisted by Department of Science and Technology, Government of India and Vice Chancellor, University of Delhi, Delhi, India.

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Vishal Chaudhary

Dr. Vishal Chaudhary is an assistant professor of Physics and Convener of Research Cell at Bhagini Nivedita College, University of Delhi, Delhi, India. He has been teaching undergraduate students since six years. His area of research includes conducting polymers, charge transport, nanostructures and nanocomposites, electromagnetic shielding, gas and vapor sensing, and science communication. He also works in interdisciplinary areas including cognitive sciences, ayurverdic sciences, sports sciences, public health and environmental sciences. He is a public speaker in mental health sciences and nano-sciences.