scholarly journals Formation of Silver Nanoparticles in PVA-PEG Hydrogel under Electron Irradiation

2019 ◽  
Vol 64 (1) ◽  
pp. 41
Author(s):  
V. B. Neimash ◽  
H. D. Kupianskyi ◽  
I. V. Olkhovyk ◽  
V. I. Styopkin ◽  
P. M. Lytvynchuk ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Irradiation ◽  
Irradiation Dose ◽  
Chemical Reduction ◽  
Total Concentration ◽  
3D Microstructure ◽  
Order Of Magnitude ◽  
Radiation Induced ◽  
Electron Irradiation Dose ◽  
Scanning Electron

The formation of silver nanoparticles in a hydrogel on the basis of polyvinyl alcohol and polyethylene glycol at its crosslinking under the electron irradiation has been studied using the optical spectroscopy and scanning electron microscopy methods. The growth of nanoparticles 40–70 nm in size and their clustering into aggregates about a few hundred nanometers in diameter are demonstrated. The total concentration of nanoparticles and their size correlate with the concentration of ionic silver in the initial solution and the electron irradiation dose. The formation of nanoparticles is interpreted as a result of the radiation-induced chemical reduction of silver in the solution that is spatially confined in the cells of a 3D microstructure in the crosslinked hydrogel. The radiation-crosslinked hydrogel demonstrates an antiseptic effect for 7 of 8 tested microorganisms at silver concentrations of 0.001–0.003 wt.%, which is at least an order of magnitude lower than effective concentrations of ionic and colloidal silvers.

The Effect of Electron Irradiation Dose on the Profile of Electric Characteristics of GaAs VPE Layers

1993 ◽  
Vol 135 (1) ◽  
pp. K21-K24 ◽  
Author(s):  
C. D. Kourkoutas ◽  
B. Kovacs ◽  
P. C. Euthymiou ◽  
B. Szentpali ◽  
K. Somogyi ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Irradiation Dose ◽  
Electron Irradiation Dose

Effect of electron irradiation dose on the performance of avalanche photodiode electron detectors

2009 ◽  
Vol 105 (1) ◽  
pp. 014506 ◽  
Author(s):  
Taizo Kawauchi ◽  
Markus Wilde ◽  
Katsuyuki Fukutani ◽  
Tatsuo Okano ◽  
Shunji Kishimoto
Keyword(s):  
Electron Irradiation ◽  
Irradiation Dose ◽  
Avalanche Photodiode ◽  
Electron Irradiation Dose

Change of Micromechanical Properties of Polyethylene Induced by a Tribological Process in Polymer/Metal System

2006 ◽  
Vol 513 ◽  
pp. 75-84 ◽  
Author(s):  
J. Maszybrocka ◽  
Jerzy Cybo ◽  
J.E. Frąckowiak ◽  
K. Krzemień
Keyword(s):  
Plastic Deformation ◽  
Electron Irradiation ◽  
Friction Surface ◽  
Irradiation Dose ◽  
Spatial Arrangement ◽  
Metal System ◽  
Micromechanical Properties ◽  
Polymer Metal ◽  
Electron Irradiation Dose ◽  
Crystallinity Band

The influence of a tribological process in the polymer/metal system on changes in microhardness (H) and Young’s modulus (E) of the surface under friction and UHMWPE volume has been studied. Twelve samples of polyethylene characterized by a different degree of initial plastic deformation and different electron irradiation dose were analyzed. For four of the samples a decrease by 5÷10 times in polyethylene degradation has been found. This result is promising in that a prolonged durability can be expected in case of application for endoprostheses acetabular cups. It has been found also that a polyethylene material irradiated after initial prestraining only once shows enhanced micromechanical properties after friction. It has been found that this result was due to reorientation of lamellas on the friction surface taking place during deformation which accompanies the tribological process. It has been proved that the increase of H and E values in the layers situated at a depth of 1.5 mm÷7.5 mm is due to a decrease of the free volume centers in the UHMWPE polyethylene and to an increase of the degree of spatial arrangement of the structure (absorption in crystallinity band of FTIR spectrum).

Radiation-Induced Precipitation at Thin Foil Surfaces in Ni-Be Alloys

1982 ◽  
Vol 40 ◽  
pp. 598-599
Author(s):  
T. Mukai ◽  
T. E. Mitchell
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Thin Foil ◽  
Homogeneous Precipitation ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Radiation Induced

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.

Antimicrobial Activity of Silver Nanoparticles Prepared Under an Ultrasonic Field

2011 ◽  
Vol 4 (3) ◽  
pp. 1491-1496
Author(s):  
Umadevi M ◽  
Rani T ◽  
Balakrishnan T ◽  
Ramanibai R
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Therapeutic Potential ◽  
Chemical Reduction ◽  
Ultrasonic Field ◽  
Great Promise ◽  
Chemical Reduction Method ◽  
E Coli

Nanotechnology has great promise for improving the therapeutic potential of medicinal molecules and related agents. In this study, silver nanoparticles of different sizes were synthesized in an ultrasonic field using the chemical reduction method with sodium borohydride as a reducing agent. The size effect of silver nanoparticles on antimicrobial activity were tested against the microorganisms Staphylococcus aureus (MTCC No. 96), Bacillus subtilis (MTCC No. 441), Streptococcus mutans (MTCC No. 497), Escherichia coli (MTCC No. 739) and Pseudomonas aeruginosa (MTCC No. 1934). The results shows that B. subtilis, and E. coli were more sensitive to silver nanoparticles and its size, indicating the superior antimicrobial efficacy of silver nanoparticles. 

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