Influence of Poly(Vinylpyrrolidone) Capping Agent on the Synthesis of Silver Structures by Polyol Method

2021 ◽  
Vol 881 ◽  
pp. 95-100
Author(s):  
Lin Cao ◽  
Yu Ying Meng ◽  
Yi Qun Zhu ◽  
Yun Ye ◽  
Qi Wei Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Silver Nanoparticles ◽  
Particle Morphology ◽  
Polyol Method ◽  
Size Analysis ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Spherical Morphology ◽  
Injection Method ◽  
Micro Structures

In this study, silver nano/micro structures were successfully synthesized from silver nitrate via a polyol method at 160 °C. In our synthesis route, ethylene glycol (EG) was used as both as solvent and reducing agent, and polyvinylpyrrolidone (PVP) with different molecular weight was employed as capping agent. When reduced the PVP’s molecular weight from 58000 to 8000, the spherical morphology of silver particles changed to rod shape. Moreover, by changing the injection method of PVP and controlling the reaction time, silver nanoparticles with uniform spherical morphology and size was prepared. The obtained silver nanoparticles were characterized by X-ray diffraction (XRD) and ultraviolet-visible spectrophotometry (UV-vis) which indicated the formation of nanoparticles. Scanning electron microscopy (SEM) contributed to the particle morphology and size analysis. The morphology and particle size of the resulting silver nanoparticles were depended on the PVP’s molecular weight and the injection method.

STRUCTURAL AND OPTICAL CHARACTERIZATION OF NANOCRYSTALLINE CuAlS2 CHALCOPYRITE SYNTHESIZED BY POLYOL METHOD IN AUTOCLAVE

2012 ◽  
Vol 26 (31) ◽  
pp. 1250179 ◽  
Author(s):  
Y. VAHIDSHAD ◽  
A. IRAJIZAD ◽  
R. GHASEMZADEH ◽  
S. M. MIRKAZEMI ◽  
A. MASOUD
Keyword(s):  
Electron Microscope ◽  
Polyethylene Glycol ◽  
Scanning Electron Microscope ◽  
Optical Characterization ◽  
Polyol Method ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Chalcopyrite CuAlS 2 nanoparticles were synthesized with polyol method. The solvothermal with autoclave nanoparticles synthesized are investigated. The amount and temperature of reducer, the solvent of salts could be important parameters that were studied. The nanoparticles were synthesized with CuCl , AlCl 3 and thiourea ( SC ( NH 2)2) as precursors, diethylene glycol (( CH 2 CH 2 OH )2 O ) and polyethylene glycol 600 ( HO ( C 2 H 4 O )n H ) as solvent and capping agent respectively, and ammonia ( NH 4 OH ) as reducing agent. The parameters of synthesis were studied by X-Ray diffraction (XRD) for analysis of structure, scanning electron microscope (SEM) for morphology and by ultraviolet–visible (UV–VIS) spectrophotometer for analysis of light structure. The possible formation mechanism is also discussed.

A Facile Route for Synthesis of Octyl Amine Capped Silver Nanoparticle

2014 ◽  
Vol 13 (03) ◽  
pp. 1450021 ◽  
Author(s):  
Nityananda Agasti ◽  
N. K. Kaushik
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Metal Ion ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Octyl Amine ◽  
Uv Visible

This paper presents a simple and convenient procedure for the preparation of octyl amine capped silver nanoparticles. AgNO 3 has been reduced by octyl amine with benzene or toluene as solvent at 100°C to produce silver nanoparticles. Octyl amine plays its role both as reducing and capping agent and thus provides the advantage of avoiding the use of extra stabilizing agent. Time dependent formation mechanism of silver nanoparticle has been investigated. Thermo gravimetric analysis (TGA) shows weight change due to loss of capping agent. The reaction can easily be monitored from variation of color with time. The method is easy and reproducible. Very low concentration (1 mM) of metal ion is used. The particles synthesized were characterized by UV-Visible, FTIR, TGA, TEM and X-ray diffraction studies.

Effect of Silver Nanoparticles in Silicalite-1 Zeolite on Antireflection and Antibacterial Performances

2015 ◽  
Vol 1125 ◽  
pp. 33-37
Author(s):  
Hye Jin Bae ◽  
Bo Kyung Lee ◽  
Hae Ryul Ok ◽  
Byung Ho Choi
Keyword(s):  
Silver Nanoparticles ◽  
Particle Size Analysis ◽  
Visible Range ◽  
Size Analysis ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
Tetrapropylammonium Hydroxide ◽  
Transmission Electron ◽  
Average Reflectance

A nano-sized zeolite has been prepared in an autoclave, using tetraethoxysilane (TEOS), tetrapropylammonium hydroxide (TPAOH) and H2O at various hydrothermal synthesis temperatures. Using transmission electron microscopy and particle size analysis, the size of the nano-sized powders was revealed to be 10–300 nm and its distribution was uniform and spherical, depending on the hydrothermal temperature. X-ray diffraction analysis confirmed that the nano-sized powder was the silicalite-1 zeolite. A coating sol could be prepared by the proper combination of these nanoparticles with a solvent. The resulting coating on the glass substrate showed an antireflection effect, with less than 2–3% average reflectance over the visible range. In addition, the effect of silver nanoparticles in the silicalite-1 zeolite on antibacterial performances was carried as a function of the amount of nano-sized silver used. With increasing amounts of nano-sized silver, the number of colony forming unit decreased and became almost to zero.

The Collagenic Molecular Structural Unit of Solid State Complexes

1971 ◽  
Vol 29 ◽  
pp. 478-479
Author(s):  
Kenneth M. Richter ◽  
John A. Schilling
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Structural Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naoh Treatment

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

Effect of synthesis and activation methods on the character of CoMo/ultrastable Y-zeolite catalysts

2021 ◽  
Vol 19 (1) ◽  
pp. 745-754
Author(s):  
Khoirina Dwi Nugrahaningtyas ◽  
Eddy Heraldy ◽  
Rachmadani ◽  
Yuniawan Hidayat ◽  
Indriana Kartini
Keyword(s):  
Electron Microscopy ◽  
Reduction Process ◽  
Particle Morphology ◽  
Zeolite Catalysts ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
X Ray ◽  
Irregular Particle ◽  
Transmission Electron ◽  
Pure Metals

Abstract The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.

scholarly journals Well-Dispersed Silver Nanoparticles on Cellulose Filter Paper for Bacterial Removal

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 595
Author(s):  
Hsiu-Wen Chien ◽  
Ming-Yen Tsai ◽  
Chia-Jung Kuo ◽  
Ching-Lo Lin
Keyword(s):  
Silver Nanoparticles ◽  
Filter Paper ◽  
X Ray Diffraction ◽  
Bacterial Reduction ◽  
Treatment Technology ◽  
Bacterial Removal ◽  
Contaminated Drinking Water ◽  
Gravity Driven ◽  
Filter Papers ◽  
Cellulose Filter

In this study, a polydopamine (PDA) and polyethyleneimine (PEI)-assisted approach was developed to generate well-distributed PDA/PEI/silver (PDA/PEI/Ag) nanocomplexes on the surfaces of commercial cellulose filter papers to achieve substantial bacterial reduction under gravity-driven filtration. PDA can bind to cellulose paper and act as a reducer to produce silver nanoparticles (AgNPs), while PEI can react with oxidative dopamine and act as a dispersant to avoid the aggregation of AgNPs. The successful immobilization of PDA/PEI/Ag nanocomplexes was confirmed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were used as pathogen models to test the efficacy of the PDA/PEI/Ag nanocomplex-incorporated filter papers. The PDA/PEI/Ag nanocomplex-incorporated filter papers provided a substantial bacterial removal of up to 99% by simple gravity filtration. This work may be useful to develop a feasible industrial production process for the integration of biocidal AgNPs into cellulose filter paper and is recommended as a local-condition water-treatment technology to treat microbial-contaminated drinking water.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

scholarly journals Development of a Solid Dispersion of Nystatin with Maltodextrin as a Carrier Agent: Improvements in Antifungal Efficacy against Candida spp. Biofilm Infections

2021 ◽  
Vol 14 (5) ◽  
pp. 397
Author(s):  
Carlos Benavent ◽  
Carlos Torrado-Salmerón ◽  
Santiago Torrado-Santiago
Keyword(s):  
Antifungal Activity ◽  
Solid Dispersions ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Candida Spp ◽  
Microbiological Techniques ◽  
Characterization Studies ◽  
Candida Albicans Biofilms

The aim of this study was to improve the treatment of Candida albicans biofilms through the use of nystatin solid dispersions developed using maltodextrins as a hyperosmotic carrier. Characterization studies by differential scanning calorimetry, X-ray diffraction, dissolution studies, and particle size analysis were performed to evaluate changes in nystatin crystallinity. Antifungal activity and anti-biofilm efficacy were assessed by microbiological techniques. The results for nystatin solid dispersions showed that the enhancement of antifungal activity may be related to the high proportions of maltodextrins. Anti-biofilm assays showed a significant reduction (more than 80%) on biofilm formation with SD-N:MD [1:6] compared to the nystatin reference suspension. The elaboration process and physicochemical properties of SD-N:MD [1:6] could be a promising strategy for treatment of Candida biofilms.

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