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Herein, silver ions modified α-Fe2O3 (Ag: α-Fe2O3) nanoparticles were synthesized using a sol-gel auto-combustion method comprising of dual phase i.e. trigonal structure of α-Fe2O3 and FCC structure of Ag. The refinement results verified the existence of both the phase with R-3c: R s and Fm-3 m space group. Transmission Electron Microscopy (TEM) showed the crystallite size around 34.24 ± 2.00 nm. The percentage of Ag0 and Ag+ verified through X-ray Photoelectron Spectroscopy (XPS) clearly indicate that around 74% of the Ag present is in the metallic form. The cyclic voltammetry showed that the Csp of the Ag: α-Fe2O3 NPs modified electrode is 132 Fg − 1 and 100 Fg − 1 when recorded at a scan rate of 50 mVs− 1 and 75 mVs− 1, respectively. The Zones of Inhibition (ZOI) against bacterial strains generated by utilizing Ag: α-Fe2O3 NPs are clearly showed the ZOI of 19 ± 1 mm against Bacillus subtilis. The synthesized nanoparticles exhibited higher inhibition against the bacterial strains in comparison to the standard antibiotic ampicillin. Further, cell viability analysis suggested to use a concentration of 9 to 12 µg/ml for Ag: α-Fe2O3in invitro experiments. [ABSTRACT FROM AUTHOR]

Purpose: Recently, there has been an upsurge among people around the world in maintaining a sustainable and hygienic environment. This is due to the over-exploitation of recourses causing environmental pollution and spreading bacterial infections. In this regard, scientists are motivated to develop smart coatings where environmental pollutants and bacterial cells are degraded when in contact with their surfaces. Design/methodology/approach: In our previous report, ZnO nanoparticles (NPs) were prepared using the precipitation technique, showing good photocatalytic and antibacterial activity [1]. In this context, the present study details the use of ZnO NPs as pigment for the fabrication of alkyd resin-based self-cleaning coating. The coating was developed by mixing ZnO NPs and alkyd resin along with the additives using the ball milling technique. The developed coating was characterized using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, atomic force microscopy, and water contact angle measurements. Findings: To elucidate the self-cleaning and hygienic behaviour of the ZnO/alkyd resin coating, the dried coating was exposed to crystal violet (CV) solution as a model dye pollutant and bacterial strains to assess its photocatalytic and antibacterial activity. The droplets of CV solution placed over the coating almost degraded after 360 min of exposure to sunlight owing to the presence of ZnO NPs in the coating. Further, the coating exhibits reasonable antibacterial activity against E. coli and P. aeruginosa whereas it displays low antibacterial activity against S. aureus. Research limitations/implications: Even though, the self-cleaning coating shows promising results, tuning the activity of the photo-catalytic pigment can improve the pollutant degradation efficiency and elevate bactericidal activity. Originality/value: ZnO NPs-impregnated alkyd resin coating for self-cleaning applications is novel. [ABSTRACT FROM AUTHOR]

This report deals with the fabrication of NiO nanoparticle (NiO Nps) dispersed alkyd coating and its antimicrobial activity. NiO Nps is prepared by novel sol-gel technique using pectic polysaccharides as a gelling agent. The gelling agent converts the hydroxo-metal network into a gel within 4 h of time. After calcination, the FESEM and TEM micrograph of the obtained NiO Nps shows cubic and irregular shaped structures with size ranging from 30 to 200 nm. The structural characterizations have been evaluated through XRD, FTIR, UV-vis and VSM studies. The antimicrobial activity of NiO Nps has been carried out against both gram negative and gram positive bacteria namely Escherichia coli, Klebsiella pneumonia and Proteus vulgaris, Streptococcus mutans, Bacillus subtilis, and Staphylococcus aureus. The findings of the present study indicate that the NiO Nps permeate the bacterial cell wall, accumulated inside thereby facilitating the synergistic impact against the growth of bacterial strains. The experimental outcomes suggest the potential use of NiO as pigments in the alkyd coating. Alkyd coating consisting of NiO Nps exhibits considerable reduction in bacterial viability when it comes in contact against microbial strains, proving the efficacy of the coating. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the corrosion behavior of zirconium carbide (ZrC) reinforced Al - Si metal matrix composites (MMCs) in a mixture of acidic solution using weight loss method. The composites are prepared by powder metallurgy method. Al-12Si-xZrC composites containing 0, 5, and 10 weight percentage of ZrC particles are compacted in a die set assembly and sintered in an inert gas muffle furnace. The acidic solutions used for corrosion are 1 N HCl, 1 N H2SO4 and 1 N HNO3. The corrosion characteristics of Al-12Si-xZrC composites and the pure Al were experimentally evaluated. The corrosion test was carried out at different weight proportions of the samples in various concentrations of the acid such as 1 N HCl, 1 N H2SO4 and 1 N HNO3 for different exposure time (i.e., 24 h, 72 h, 144 h and 216 h), respectively. The results specified that corrosion rate of composites was lower than that of base metal Al under the corrosive atmosphere, regardless of exposure time and acidic solutions used as corrodents. Al-12Si-xZrC composites become more corrosion resistant as the ZrC content is increased. This is because of the development of stable oxide layer above the specimens. Scanning electron microscopy (SEM) confirms the degree of attack of acidic solution on the surface of the examined material. [ABSTRACT FROM AUTHOR]

The chances of curing and reducing the adverse effect of cancer partly lie in early detection. Colorimetric sensor-based technique show promising results since the target is detected with high sensitivity but without the use of advanced/costly techniques through a simple visual color change. In most cases, gold nanoparticles (Au Nps) functionalized with biomolecules complementary to target analyte are used for colorimetric detection. The interaction of functionalized Au Nps with target analytes induce aggregation or dispersion where the color of the solution changes from red to blue or blue to red respectively, which can be visualized by the naked eyes. Such a facile technique has a high commercial viability and therefore, understanding its concept is essential. Here, some of the reported studies are discussed technically for better understanding about the invitro colorimetric detection of cancer., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Herein, we report the fabrication and characterization of hybrid electrode material for supercapacitor applications. CaCO 3 nanoparticles (Nps) are used as intercalator to avoid the restacking behavior of reduced graphene oxide (rGO) nanosheets. CaCO 3 Nps and rGO sheets are fabricated employing precipitation technique and microwave irradiation method, respectively. The intercalation process is performed by magnetic stirring followed by ultra-sonication technique. As prepared CaCO 3 Nps, rGO and rGO intercalated with 2.5 wt.% and 5 wt.% CaCO 3 Nps are characterized using X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy to evaluate the crystalline characteristics, molecular vibrations, and morphology, respectively. The prepared electrode materials are coated separately on the glassy carbon electrode and their electrochemical performance displayed remarkable capacitance values for rGO nanosheets intercalated with 2.5 wt.% and 5 wt.% CaCO 3 Nps. From the obtained results, it is clear that the specific capacitance of 2.5 wt.% CaCO 3 intercalated rGO displays higher specific capacitance of 84.5 F/g at 5 mV/s with high retention stability. The mechanism behind the improvement in the electrochemical behavior is due to the increase in active surface area which is explained via Brunauer-Emmett-Teller analysis and energy-dispersive X-ray spectroscopic analysis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Herein, we reported the photo-catalytic degradation/anti-bacterial property of Ag-doped ZnO nanoparticles (SDZO Nps) prepared by a facile gel-combustion technique and its self-cleaning/self-refreshing/self-disinfectant behaviour while on impregnating as pigment into the alkyd resin based coating. The influence of doping Ag (1% & 2%) with ZnO has been evaluated in terms of crystal structure, morphology, optical properties, etc. using X-ray diffraction analysis, Field Emission Scanning Electron Microscope, UV-Vis analysis, and Photoluminescence spectra. The photo-catalytic degradation of crystal violet solution by SDZO Nps is spectroscopically followed employing UV-Vis spectroscopy. From the obtained results, the rate of degradation of 1% SDZO Nps is found higher than that of other samples under sunlight illumination; degrading 1 mg of crystal violet in 30 min. Thus, implementing the synergic effect of nano ZnO and the doped Ag provides a suitable pathway for the development of high efficient photo-catalyst. Further, alkyd resin based self-cleaning coating is formulated using 1% SDZO Nps as pigment along with other additives; the contents are milled to form a homogeneous mixture by high energy ball milling technique. Crystal violet solution coated over dried alkyd coating gets decolorized on exposure to sunlight indicating the mineralization of pollutants and proves the fact that the as obtained coating possess self-cleaning nature. Besides the self-cleaning property, the coating exhibits self-refreshing property which is essential for the long lasting self-cleaning activity. Further, the disinfectant properties of 1% SDZO Nps and 1% SDZO Nps impregnated coating have been evaluated against gram negative Escherichia coli bacterial strain. The acquired experimental outcomes suggest the potential use of self-cleaning coating to keep the environment clean and hygienic economically., (Copyright © 2018 Elsevier Inc. All rights reserved.)