Rajeev Kuma; Saroj Kumari;S. Das; D.P. Mondal; Shyam Birla; Amit Vishwakarma; Anisha Chaudhary
Abstract
In the present investigation, influence of micronsize cenosphere particles derived from fly ash on the properties of aluminum composites was investigated. Aluminum-cenosphere (AC) composite was fabricated by modified stir casting technique. The mechanical and electromagnetic interference (EMI) shielding ...
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In the present investigation, influence of micronsize cenosphere particles derived from fly ash on the properties of aluminum composites was investigated. Aluminum-cenosphere (AC) composite was fabricated by modified stir casting technique. The mechanical and electromagnetic interference (EMI) shielding properties of AC composites were investigated. The obtained composites with cenosphere (+100 µm) loading demonstrate the excellent compressive strength of 251.3 MPa. This enhancement is due to the smaller size of cenosphere size provides the finer surface of the cenosphere. The addition of cenosphere in aluminum matrix improved dielectric and microwave absorption properties of composites in X band frequency region (8.2-12.4 GHz). The AC composites possess good EMI shielding effectiveness of -32.7 to -44.3 dB with 30% loading of cenosphere with various sizes (+212, +150 and +100 µm). The incorporation of lower size cenosphere (+100µm) in aluminum matrix significantly increases the interfacial polarization which leads to a higher absorption EMI shielding effectiveness (SE) of -31.1 dB at 2.0 mm thickness. This technique is very simple, economical and highly reproducible, which may facilitate the commercialization of such composite and it can be used as microwave absorbing materials in defense and aerospace applications.
Satish Teotia; B.P. Singh; Anisha Chaudhary; Indu Elizabeth; Anchal Srivastava; Saroj Kumari; S. R. Dhakate; S. Gopukumar; R. B. Mathur
Abstract
The quick advancement of flexible energy storage gadgets has persuaded individuals to look for reliable electrodes with high mechanical flexibility and remarkable electrochemical performance. In the present study, we demonstrate a simple and scalable process to fabricate a flexible, light-weight, free-standing ...
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The quick advancement of flexible energy storage gadgets has persuaded individuals to look for reliable electrodes with high mechanical flexibility and remarkable electrochemical performance. In the present study, we demonstrate a simple and scalable process to fabricate a flexible, light-weight, free-standing polyvinylidene fluoride-multiwalled carbon nanotubes (PVDF-MWCNT) composite paper, which can be specifically utilized as a flexible anode for lithium ion batteries (LIBs). The excellent binding of MWCNT with PVDF matrix, developed by a straightforward vacuum filtration process, provides sufficient structural integrity to the composite paper. The breaking strength of the PVDF-MWCNT composite paper so formed is found to be 3.5 MPa with strain to failure of 11.25%. The composite paper so developed shows a good cycle reversible charge capacity when used as anode in a standard Li-ion battery. The PVDF-MWCNT composite paper provides a novel pathway to large scale fabrication of flexible electrodes which can be used without conducting support of copper sheet.
Anisha Chaudhary; Ashish Gupta; Rakesh B. Mathur; Sanjay R. Dhakate
Abstract
Electrospun nanofibers based antimicrobial filter were examined for their capability to build conductive environment. An antimicrobial agent, silver nitrate (AgNO3), was added to the nanofibers membrane for its ability to prevent growth of microorganisms over the filter media. In this direction in the ...
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Electrospun nanofibers based antimicrobial filter were examined for their capability to build conductive environment. An antimicrobial agent, silver nitrate (AgNO3), was added to the nanofibers membrane for its ability to prevent growth of microorganisms over the filter media. In this direction in the present investigation the different fractions of silver nanoparticles were in-situ synthesized in PAN solution and then polyacrylonitrile (PAN)-silver composite nanofibers membrane filter was prepared by electrospinning technique. The resultant solution and PAN-silver composite nanofibers was characterized by UV–visible spectroscopy, scanning electron microscope, atomic force microscope and X-ray diffraction. Antibacterial property of PAN silver composite nanofibers were investigated against gram positive Staphylococcus aureus and gram negative Escherichia coli microorganisms. The formation of clear zone suggests that composite nanofibers containing silver nanoparticles show strong antibacterial activity and it increases with increasing silver content in the composite nanofibers. The PAN-silver composite nanofibers sheet was also examined for filtration of microorganisms and dust particles. It was observed that PAN-silver composite nanofibers filter proven to be an excellent filter for creating microorganism and dust free hygienic environment. Thus electrospun PAN nanofibers filters containing an antibacterial agent can be a promising solution for effective microorganism filtration from indoor air in hospitals or other places which are more prone to bacterial infections.
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