A. Ferin Fathima; R. Jothi Mani; K. Sakthipandi
Abstract
Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O nanoparticles (NPs) have been synthesized via poly ethylene glycol assisted route. The average crystallite size of Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O NPs were estimated from X-ray diffraction results and the values are 31.38 nm and 36.14 nm respectively. ...
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Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O nanoparticles (NPs) have been synthesized via poly ethylene glycol assisted route. The average crystallite size of Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O NPs were estimated from X-ray diffraction results and the values are 31.38 nm and 36.14 nm respectively. The UV absorption spectra confirmed the formation of the NPs with the characteristic peaks at 374 and 366 nm respectively. This spectral observation indicates that the band gap of ZnO nanoparticles decreases by doping iron/gold and cobalt/gold nanoparticles. The morphology and elemental composition of Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O NPs were investigated. The antifungal activity of synthesized Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O NPs were found against four postharvest pathogenic fungi like Aspergillus niger, Aspergillus flavus, Rhizopus microsporus and Pencillium sp. The doping of iron and gold in ZnO nanoparticles enhances the zone of inhibition for the fungal pathogens compared to pure ZnO nanoparticles. Antifungal activity of Zn0.98Fe0.01Au0.01O and Zn0.98Co0.01Au0.01O nanoparticles were higher when compared with standard antibiotic mycostatin whose zone of inhibition is 18 mm against Aspergillus niger, Aspergillus flavus, Rhizopus microsporus and Pencillium sp.
Hediyeh Nejati Rad; Aliasghar Behnamghader; Mojgan Bagheri; Masoud Mozafari
Abstract
In this study, mesoporous bioactive glass 77S was synthesized by sol-gel method using two different ionic and nonionic surfactants. Physical-chemical properties of synthesized Bioglass were studied using techniques include X-ray diffraction, scanning electron microscopy, nitrogen adsorption and Fourier ...
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In this study, mesoporous bioactive glass 77S was synthesized by sol-gel method using two different ionic and nonionic surfactants. Physical-chemical properties of synthesized Bioglass were studied using techniques include X-ray diffraction, scanning electron microscopy, nitrogen adsorption and Fourier transform infrared spectroscopy. The results showed that using nonionic and ionic surfactants increased specific surface area by 3 and 5 times, respectively. By determining the silicon release in three different temperatures, the activation energy values of Si-O-Si for sample with surface area of 161 and 94 m 2 /g were calculated 1/10 and 1/5 of control glass with surface area of 34 m 2 /g. The pH of sample was evaluated in solutions buffered with TRIS. pH analysis results suggested a direct relation between surface area and pH changes, the greatest increase in pH was observed in the sample with the highest surface area. Moreover, the in vitro bioactivity test was also conducted in simulated body fluid (SBF) and formation of apatite layer was evaluated by scanning electron microscopy and X-ray diffraction after a day.
Mpho W. Maswanganye; Koena E. Rammutla; Thuto E. Mosuang; Bonex W. Mwakikunga; Sone T. Bertrand; Malik Maaza
Abstract
Co and In co-doped nanopowders of ZnO as well as In and Co singly doped ZnO were successfully prepared using sol-gel method. The synthesized samples were characterized using x-ray diffraction (XRD), UV-vis spectroscopy (UV-vis), Raman spectroscopy (RS), Transmission Electron Microscopy (TEM) and Energy ...
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Co and In co-doped nanopowders of ZnO as well as In and Co singly doped ZnO were successfully prepared using sol-gel method. The synthesized samples were characterized using x-ray diffraction (XRD), UV-vis spectroscopy (UV-vis), Raman spectroscopy (RS), Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDS). The effects of In and Co co-doping on the structural and optical properties were investigated. XRD results showed no peaks associated with In 3+ or Co 2+ ions indicating that In 3+ and Co 2+ ions substituted for Zn 2+ ions in the ZnO wurtzite structure, this was corroborated by the EDS results. Doping ZnO nanoparticles with In and Co significantly reduced the grain sizes whereas the lattice parameters were not significantly affected. TEM results confirmed that the nanoparticles were spherically shaped. Raman spectroscopy also confirmed that the ZnO nanoparticles were of a wurtzite hexagonal structure. Single doping reduced the energy band gaps and co-doping reduced them even further.
R.P. Koirala; I.S. Jha;D. Adhikari; B.P. Singh
Abstract
Quasi-chemical approximation has been used to study the mixing behaviour of liquid aluminium-gallium binary alloys by computing thermodynamic functions, such as free energy of mixing, heat of mixing, entropy of mixing, activity and microscopic functions, such as concentration fluctuation in long wavelength ...
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Quasi-chemical approximation has been used to study the mixing behaviour of liquid aluminium-gallium binary alloys by computing thermodynamic functions, such as free energy of mixing, heat of mixing, entropy of mixing, activity and microscopic functions, such as concentration fluctuation in long wavelength limit (Scc(0)), Warren-Cowley short range order parameter ( ) and ratio of diffusion coefficients of the alloys at 1023 K. The theoretical analysis reveals that the ordering energy is found to be temperature dependent and Al-Ga alloy in molten state is slightly segregating.
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