scholarly journals Study of Band Gap of Silver Nanoparticles—Titanium Dioxide Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
P. Barone ◽  
F. Stranges ◽  
M. Barberio ◽  
D. Renzelli ◽  
A. Bonanno ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Band Gap ◽  
Chemical Properties ◽  
Photoelectrochemical Cells ◽  
Visible Range ◽  
X Ray ◽  
Optical Absorbance ◽  
Laser Ablation Process ◽  
Uv Visible ◽  
And Chemical Properties

The optical and chemical properties of Ag/TiO2nanocomposites were investigated to explore the possibilities of incorporating these new materials in Gratzel photoelectrochemical cells. The nanocomposites were obtained doping TiO2, in both allotropic species anatase and rutile, with silver nanoparticles (grown by laser ablation process). X-ray photoelectron data indicate the absence of Ag-Ti chemical bonds, while measurements of photoluminescence and optical absorbance in UV-visible range show a quench in photoluminescence emission of about 50% and an increase in visible absorbance of about 20%. Measurements of optical band gap, obtained by Tauc’s equation, indicate a variation of about 1.6 eV.

scholarly journals Green synthesis of silk sericin-embedded silver nanoparticles and their antibacterial application against multidrug-resistant pathogens

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Md. Abdullah Al Masud ◽  
Hamid Shaikh ◽  
Md. Shamsul Alam ◽  
M. Minnatul Karim ◽  
M. Abdul Momin ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Bombyx Mori ◽  
Multidrug Resistant ◽  
Visible Spectroscopy ◽  
Silk Sericin ◽  
X Ray ◽  
Synthesis Strategy ◽  
Uv Visible ◽  
Multidrug Resistant Pathogens

Abstract Background The green synthesis strategy of metallic nanoparticles (NPs) has become popular due to being environmentally friendly. Stable silver nanoparticles (AgNPs) have been synthesized by natural products such as starch, soy protein, various extract of leaves, barks, and roots functioning both as reducing and stabilizing agents. Likewise, silk sericin (SS) is a globular protein discarded in the silk factory might be used for NP synthesis. In this research, we focus on the green synthesis and stabilization of AgNPs by SS as well as assessment of their antibacterial activities against some drug-resistant pathogen. Results SS was extracted from Bombyx mori silkworm cocoons in an aqueous medium. 17 w/w% of dry sericin powder with respect to the cocoon’s weight was obtained by freeze-drying. Furthermore, AgNPs conjugated to sericin, i.e., SS-capped silver nanoparticles (SS-AgNPs) were synthesized by easy, cost-effective, and environment-friendly methods. The synthesized SS-AgNPs were characterized by UV-visible spectroscopy, Fourier-transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction measurement. It has been found from the absorbance of UV-visible spectroscopy that a higher percent of SS-AgNPs was obtained at a higher concentration of silver nitrate solution. FTIR-ATR spectra showed that the carboxylate groups obtained from silk sericin act as a reducing agent for the synthesis of silver nanoparticles, while NH2+ and COO− act as a stabilizer of AgNPs. The X-ray diffractogram of SS-AgNPs was quite different from AgNO3 and sericin due to a change in the crystal structure. The diameter of AgNPs was around 20–70 nm observed using TEM. The synthesized SS-AgNPs exhibited strong antibacterial activity against multidrug-resistant pathogens, Escherichia coli and Pseudomonas aeruginosa. Minimal inhibitory/bactericidal concentrations against E. coli and P. aeruginosa were 20μg/mL. Conclusions This study encourages the use of Bombyx mori for the ecofriendly synthesis of SS-AgNPs to control multidrug-resistant microorganisms.

Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Scott Schlorholtz ◽  
Ken Bergeson ◽  
Turgut Demirel
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
High Calcium ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

scholarly journals PHYSICAL AND CHEMICAL STUDIES OF OVERROOF ROCKS OF CLAY SHALES OF THE DZHERDANAK DEPOSIT

2021 ◽  
pp. 16-21
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Chemical Properties ◽  
Mineralogical Composition ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Clay Shales ◽  
Chemical Studies ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this study is study of the physical and chemical properties of the overburden of the Dzherdanak deposit. The chemical and mineralogical composition of the overburden of the Djerdanak deposit has been studied by the methods of X-ray and thermography, electron microscopy and infrared spectroscopy. The main phases are quartz, kaolinite and muscovite. The study of the fine structure of the rock under an electron microscope showed the homogeneity of the rock with pronounced uniform inclusions, which is preserved even after firing. Changes in the rock after firing at 1050 °C have been determined. The formation of mullite at this temperature has been established.

scholarly journals Bio Synthesis and Characterization of Silver Nanoparticles Using Lagenaria siceraria Leaf Extract and their Antibacterial Activity

2014 ◽  
Vol 38 ◽  
pp. 35-45 ◽  
Author(s):  
B. Anandh ◽  
A. Muthuvel ◽  
M. Emayavaramban
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Face Centered Cubic ◽  
Lagenaria Siceraria ◽  
Human Pathogens ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Ft Ir ◽  
Uv Visible

The present investigation demonstrates the formation of silver nanoparticles by the reduction of the aqueous silver metal ions during exposure to the Lagenaria siceraria leaf extract. The synthesized AgNPs have characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. AgNPs formation has screened by UV-visible spectroscopy through colour conversion due to surface plasma resonance band at 427 nm. X-ray diffraction (XRD) confirmed that the resulting AgNPs are highly crystalline and the structure is face centered cubic (fcc). FT-IR spectrum indicates the presence of different functional groups present in the biomolecules capping the nanoparticles. Further, inhibitory activity of AgNPs and leaf extract were tested against human pathogens like gram-pastive (Staphylococcus aureus, Bacillus subtilis), gram-negative (Escherichia coli and Pseudomonas aeruginosa). The results indicated that the AgNPs showed moderate inhibitory actions against human pathogens than Lagenaria siceraria leaf extract, demonstrating its antimicrobial value against pathogenic diseases

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

scholarly journals Fracture analysis and countermeasures of the grid switch castings

2020 ◽  
Vol 165 ◽  
pp. 06015
Author(s):  
Chao Feng ◽  
Siyuan Yang ◽  
Qiao Li ◽  
Mengbao Zhou ◽  
Songqi Wu ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Fracture Analysis ◽  
Casting Defects ◽  
Physical And Chemical Properties ◽  
Direct Reading ◽  
X Ray ◽  
Detection Technology ◽  
Two Stages ◽  
Physical And Chemical ◽  
And Chemical Properties

Based on the detection technology of direct reading spectrum, metallographic microscope and X-ray, the defects of the grid switch castings were analyzed. The four main forms of casting fracture were summarized as poor physical and chemical properties, material misuse, casting defects and designing defects. In order to strengthen the quality control of the source of the product, it was proposed to carry out targeted network inspection in the two stages of material arrival and infrastructure acceptance.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

Mythology Merges with Technology for Majestic Production of Silver Nanoparticles: Rudraksha Enabled

2012 ◽  
Vol 585 ◽  
pp. 144-148
Author(s):  
Poushpi Dwivedi ◽  
S.S. Narvi ◽  
R.P. Tewari
Keyword(s):  
Silver Nanoparticles ◽  
Vital Role ◽  
Environmentally Benign ◽  
Size Analysis ◽  
Visible Spectroscopy ◽  
Efficient Manner ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Cost Efficient

In this nanoregime attempts to bring forth nanoparticles and nanomaterials are myriads, with there interesting and demanding applications in almost every field. Today the field of nanoscience has bloomed with the confluence of nanotechnology with material science, biology, biotechnology and medicine and the need for nanotechnology will only increase as miniaturization becomes extremely important in various arrays of life. Since time immemorial silver nanoparticles have been extensively used for hygienic and healing purposes, and even until most recently, it has indispensible vital role especially in the biomedical arena. Thus in an attempt to generate silver nanoparticles employing green, environmentally benign route, we have designed to converge mythology with technology, with the mystical production of silver nanoparticles, enabled by the blueberry beads of the plant Elaeocarpus granitrus Roxb., the Rudraksha. This non-degradable bead does not disintegrate, but retains the potentiality, even after unlimited production of silver nanoparticles, assisting infinite times. The extremely cost-efficient nanoparticles thus developed in a superiorly efficient manner were characterized through different techniques; like UV/visible spectroscopy, PL spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and nanoparticle size analysis.

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