γ-ray effects on PMMA polymeric sheets doped with CdO nano particles

ABSTRACTDilute aqueous solutions with Au3+ ions and Polyethylene Glycol Monostearate are irradiated with ∼1 MeV γ-ray from 60Co source, 10 MeV pulsed electrons or 1.6 GeV carbon ions. After the irradiation, the color of solutions changes from buff yellow to reddish color. The UV-vis absorption spectra show that after the irradiation, light absorption around 530 nm appears, which corresponds to the excitation of the surface plasmon due to Au nano-particles. The result confirms that the irradiation reduces Au3+ ions in the aqueous solutions and synthesizes Au nano-particles. Size and shape of the nano-particles are examined by using 200kV transmission electron microscope. Effects of irradiation parameters (total dose and dose rate) on Au nano-particle synthesis are discussed.

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Effect of Gamma-Ray Irradiation on the Growth of Au Nano-Particles Embedded in the Germano-Silicate Glass Cladding of the Silica Glass Fiber and its Surface Plasmon Resonance Response

Sensors ◽

10.3390/s19071666 ◽

2019 ◽

Vol 19 (7) ◽

pp. 1666 ◽

Cited By ~ 1

Author(s):

Seongmin Ju ◽

Won-Taek Han

Keyword(s):

Refractive Index ◽

Surface Plasmon Resonance ◽

Total Dose ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Silica Glass ◽

Nano Particles ◽

Au Nps ◽

Γ Ray ◽

Au Nano Particles

The effect of γ-ray irradiation on the surface plasmon resonance (SPR) sensing capability of refractive index (n = 1.418–1.448) of the silica glass optical fiber comprised of germano-silicate glass cladding embedded with Au nano-particles (NPs) was investigated. As the γ-ray irradiation increased from 1 h to 3 h with the dose rate of 1190 Gy/h, the morphology of the Au NPs and the SPR spectrum were found to change. The average diameter of Au NPs increased with the aspect ratio from 1 to 2, and the nano-particles became grown to the clusters. The SPR band wavelength shifted towards a longer wavelength with the increase of total dose of γ-ray irradiation regardless of the corresponding refractive indices. The SPR sensitivities (wavelength/refractive index unit, nm/RIU) also increased from 407 nm/RIU to 3553 nm/RIU, 1483 nm/RIU, and 2335 nm/RIU after the γ-ray irradiation at a total dose of 1190 Gy, 2380 Gy, and 3570 Gy, respectively.

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Neutron and γ-ray effects measured by the micronucleus test

Mutation Research Letters ◽

10.1016/0165-7992(82)90005-7 ◽

1982 ◽

Vol 105 (3) ◽

pp. 157-162 ◽

Cited By ~ 9

Author(s):

Michael L. Garriott ◽

Douglas Grahn

Keyword(s):

Micronucleus Test ◽

Γ Ray ◽

Ray Effects

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Electron holography of catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138452 ◽

1995 ◽

Vol 53 ◽

pp. 416-417

Author(s):

A. K. Datye ◽

D. S. Kalakkad ◽

L. F. Allard ◽

E. Völkl

Keyword(s):

Heterogeneous Catalysts ◽

High Surface ◽

High Surface Area ◽

Atomic Scale ◽

Nano Particles ◽

Phase Image ◽

Electron Holography ◽

Specimen Thickness ◽

Phase Information ◽

Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

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Coherent electron nanodiffraction from clean silver nano particles in a UHV STEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015112x ◽

1993 ◽

Vol 51 ◽

pp. 1058-1059

Author(s):

J. Liu ◽

M. Pan ◽

G. E. Spinnler

Keyword(s):

Supported Catalysts ◽

Imaging Techniques ◽

Nano Particles ◽

Metal Particles ◽

Shape Structure ◽

Dynamical Simulations ◽

Small Metal Particles ◽

Extract Information

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.

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