The last decade has observed a rapid advancement in utilising biological system towards bioremediation of metal ions in the form of respective metal nanostructures or microstructures. The process may also be adopted for respective metal nanoparticle biofabrication. Among different biological methods, bacteria‐mediated method is gaining great attention for nanoparticle fabrication due to their eco‐friendly and cost‐effective process. In the present study, silver nanoparticle (AgNP) was synthesised via continuous biofabrication using Aeromonas veronii, isolated from swamp wetland of Sunderban, West Bengal, India. The biofabricated AgNP was further purified to remove non‐conjugated biomolecules using size exclusion chromatography, and the purified AgNPs were characterised using UV–visible spectroscopy, X‐ray diffraction, field emission scanning electron microscopy and transmission electron microscopy (TEM). Additionally, the presence of proteins as capping and stabilising agents was confirmed by the amide‐I and amide‐II peaks in the spectra obtained using attenuated total reflection Fourier transform infrared spectroscopy. The size of biofabricated AgNP was 10–20 nm, as observed using TEM. Additionally, biofabricated AgNP shows significant antibacterial potential against E. coli and S. aureus. Hence, biofabricated AgNP using Aeromonas veronii, which found resistant to a significant concentration of Ag ion, showed enhanced antimicrobial activity compared to commercially available AgNP.Inspec keywords: silver, nanoparticles, microorganisms, nanofabrication, purification, chromatography, ultraviolet spectra, visible spectra, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, proteins, molecular biophysics, biochemistry, molecular configurations, attenuated total reflection, Fourier transform infrared spectra, particle size, antibacterial activity, biomedical materials, nanomedicineOther keywords: capping agents, stabilising agents, amide‐I peaks, amide‐II peaks, attenuated total reflection Fourier transform infrared spectroscopy, antibacterial potential, E. coli, S. aureus, Aeromonas veronii, antimicrobial activity, size 10 nm to 20 nm, Ag, proteins, TEM, transmission electron microscopy, field emission scanning electron microscopy, X‐ray diffraction, UV‐visible spectroscopy, size exclusion chromatography, nonconjugated biomolecules, purification, swamp wetland, Aeromonas veronii, cost‐effective process, eco‐friendly, bacteria‐mediated method, biological methods, metal nanoparticle biofabrication, microstructures, metal nanostructures, metal ions, bioremediation, biological system, mangrove swamp, bacteria, silver nanoparticles相似文献
Bi0.617Y0.05Cu3Ti4O12(BYCTO) was successfully synthesized through an economically semi-wet route using metals nitrates, acetate, and TiO2 precursor and sintered at 1173 K for 8 h. The single phase of ceramic was authorized by XRD analysis. The crystallite size of BYCTO ceramic was calculated to be 62.3 nm through XRD measurement. The particle size obtained by TEM analysis was to be in the range of 55?±?7 nm. The average grain size observed through the SEM technique was 0.783 μm. The route means square roughness, as well as average roughness, were determined to be 0.224 μm and 0.179 μm by atomic force microscope. The dielectric constant (?′) of BYCTO was measured to be 1481 at 307 K and 100 Hz. The tangent loss (tan δ) was observed to be in the range of 0.13–0.29 at all selected temperatures (307–487 K) and 10 kHz which is lower than that of Bi2/3Cu3Ti4O12. The oxidation state of all metal present in the ceramic material was verified by XPS analysis.
A study based on two-dimensional percolation theory yielding quantitative parameters for optimum connectivity of transparent single-wall carbon nanotube (SWNT) thin films is reported. Optimum SWNT concentration in the filtrated solution was found to be 0.1 mg/L with a volume of 30 mL. Such parameters lead to SWNT fractions in the films of approximately Phi = 1.8 x 10(-3), much below the metallic percolation threshold, which is found to be approximately PhiC = 5.5 x 10(-3). Therefore, the performance of transparent carbon nanotube thin-film transistors is limited by the metallic SWNTs, even below their percolation threshold. We show how this effect is related to hopping or tunneling between neighboring metallic tubes. 相似文献
Polypyrrole (PPy) is polymerized by chemical oxidative polymerization in presence of anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate
(DEHS) as the dopant. The electrical conductivity was optimized in terms of oxidant to monomer molar ratio and polymerization yield
was measured for these reactions. We have used ammonium persulphate (APS) as the oxidant for polymerization in this series of experiments. The effect of concentration of oxidant on the electrical
conductivity is examined. Chemical synthesis of polypyrrole is supported by FTIR spectrum. The electrical conductivity of
doped and undoped polypyrrole has been measured in the temperature range of 10–300 K and is found to increase with rise in
temperature. Electrical conductivity of PPy was analyzed in the light of various charge transport models. Analysis of the electrical conductivity data reveals that in
the temperature range 60–300 K electrical transport is predominantly governed by power law behaviour given by Kivelson model.
However in the low temperature range 10–60 K electrical transport is dominated by the fluctuation assisted mechanism. 相似文献
Hard, refractory thin films consisting of group IVB element mono-nitrides deposited using various chemical and physical vapour-deposition techniques are widely used in wear-resistant applications. As the demand for performance exceeds the capabilities of existing materials, new materials with superior properties must be developed. Here we report the realization and characterization of hard cubic Zr3N4 (c-Zr3N4) thin films. The films, deposited using a novel but industrially viable modified filtered cathodic arc (FCA) method, undergo a phase transformation from orthorhombic to cubic above a critical stress level of 9 GPa as determined by X-ray diffraction and Raman spectroscopy. The c-Zr3N4 films are significantly harder (approximately 36 GPa) than both the orthorhombic Zr3N4 (o-Zr3N4) and ZrN films (approximately 27 GPa). The ability to deposit this material directly onto components as a thin film will allow its use in wear- and oxidation-resistant applications. 相似文献
Si–O deoxidation equilibria in liquid steel are not reliably known, especially in the high silicon concentration range. Herein, Si–O deoxidation equilibria in liquid steel at 1823–1873 K have been investigated for a wide range of silicon concentrations. Thermodynamic analysis was carried out using Wagner's interaction parameter formalism (WIPF) and FactSage 8.1. The first and second-order cross-interaction parameters estimated at 1873 K are as follows: , , . Moreover, nonmetallic inclusion characteristics were also investigated for varying silicon concentrations. 相似文献