Effect of Buffer on the Optical Properties of Irradiated Hydroxyethyl Methacrylate Copolymer

2002 ◽  
Vol 17 (5) ◽  
pp. 1199-1207
Author(s):  
K. F. Chou ◽  
C. C. Han ◽  
Sanboh Lee
Keyword(s):  
Optical Properties ◽  
Irradiation Dose ◽  
Ph Value ◽  
Bathochromic Shift ◽  
Cutoff Wavelength ◽  
Hydroxyethyl Methacrylate ◽  
Γ Irradiation ◽  
Incident Wavelength ◽  
Γ Ray ◽  
Methacrylate Copolymer

The effect of buffer and γ irradiation on the optical properties of hydroxyethyl methacrylate (HEMA) copolymer was investigated. The transmission of HEMA copolymer decreased with the increase of irradiation dose and/or pH value of the buffer. The cutoff wavelength of HEMA copolymer exhibits a bathochromic shift as the γ-ray dose and/or pH value of buffer increases. The influence of atmosphere during γ-ray irradiation on the optical properties of HEMA copolymer was investigated. The change of optical properties of HEMA copolymer irradiated in air was more pronounced than that irradiated in vacuum. Light was scattered by holes in the polymer. The relationship between scattering intensity (Is) and incident wavelength (λ) can be described by the formula Is ∝ λ−n. The span of holes increases with the irradiation dose regardless of radiation atmosphere and pH value in the range of 4.1–6.5. A boundary between the inner and outer layers of HEMA copolymer irradiated in air was observed, separating two differential morphologies of holes.

Positron Lifetimes and Crystallinity of γ-Irradiated Polypropylenes

2012 ◽  
Vol 733 ◽  
pp. 163-166
Author(s):  
Zhe Chen ◽  
Wei Huang ◽  
Peng Fei Fang ◽  
Wen Yu ◽  
Shao Jie Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Irradiation Dose ◽  
Gamma Ray ◽  
Positron Lifetime ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Γ Ray ◽  
Positron Lifetimes ◽  
Dsc Method ◽  
Low Irradiation

The microstructure of the polypropylenes (PP) irradiated by gamma ray was studied by positron lifetime technique and differential scanning calorimetry (DSC). Lifetime measurement shows o-Ps intensity decreases with increasing γ irradiation dose. The crystallinity of irradiated samples was detected by DSC method. The correlation between o-Ps intensity and crystallinity indicates γ-ray can induce higher crystallinity in the polypropylene at low irradiation dose.

Changes in structural and optical properties due to γ-irradiation of MgO nanoparticles

2020 ◽  
Vol 108 (4) ◽  
pp. 315-320
Author(s):  
Maryam Amini ◽  
Mohammad Hossein Majles Ara
Keyword(s):  
Optical Properties ◽  
Dose Rate ◽  
Structural Properties ◽  
Gamma Spectroscopy ◽  
Hexagonal Lattice ◽  
Crystal Defects ◽  
Γ Irradiation ◽  
Mgo Nanoparticles ◽  
Before And After ◽  
Γ Ray

AbstractIn this research, the influence of γ-irradiation on the optical and structural properties of magnesium oxide (MgO) nanoparticles was studied. The MgO nanoparticles were irradiated with doses 100 Gy, 1 kGy, 10 kGy and 20 kGy from 60Co source. The as-synthesized samples of MgO nanoparticles prepared by the sol-gel technique were analyzed by XRD which suggested the double phase; cubic and hexagonal structures of the material. The crystal defects that produced in the cubic and hexagonal lattice were studied before and after 60Co γ-irradiation in a gamma cell by different dose rates in order to report the changes in structural properties of the MgO nanoparticles. The irradiated and un-irradiated samples were characterized by XRD and UV–Vis. The XRD pattern of MgO nanoparticles is showed that the crystal size of MgO nanoparticles being increased with increasing the γ-ray dose rate. For optical absorption, the UV–Visible absorption spectra of MgO nanoparticles are showed that when the dose rate is increased, the value of band gap is decreased. Also, the experimental values of the mass attenuation coefficient of MgO nanoparticles have been calculated before and after γ-irradiation by using the gamma spectroscopy method. Therefore, the results are showed that γ-ray irradiation has various effects on structural, morphological and optical properties.

MEASUREMENT THE EFFECT OF γ-IRRADIATION DOSES ON AlCu8.5 BY POSITRON ANNIHILATION DOPPLER-BROADENING SPECTROSCOPY

2007 ◽  
Vol 21 (22) ◽  
pp. 3901-3907
Author(s):  
M. A. ABDEL-RAHMAN ◽  
M. ABDEL-RAHMAN ◽  
M. ABO-ELSOUD ◽  
M. F. EISSA ◽  
YAHIA A. LOTFY ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Irradiation Dose ◽  
Room Temperature ◽  
Doppler Broadening ◽  
Γ Irradiation ◽  
Second Stage ◽  
S Parameter ◽  
Controlling Mechanism ◽  
Γ Ray ◽  
Two Stages

The effect of irradiation dose (kGy) on a set of AlCu 8.5 samples has been studied. The samples were irradiated to doses of 10, 30, 50, 70, 100, 300, 500, 700 and 1000 kGy of 60 Co γ-source at room temperature. The effect of γ-ray irradiation on the values of the S- and W-parameters reveals two stages. In the first stage, the S-parameter increases, while the W-parameter decreases up to 70 kGy. In the second stage, the S- and W-parameters decrease and increase respectively in the dose region from 100 to 1000 kGy. The dominant controlling mechanism of the S- and W-parameters was observed.

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

Structural studies and optical properties of pearl nucleus irradiated by γ-ray

2013 ◽  
Vol 168 (9) ◽  
pp. 696-704
Author(s):  
Hea-Yeon Kim ◽  
Younes Hanifehpour ◽  
Arghya Narayan Banerjee ◽  
Bong-Ki Min ◽  
Sang Woo Joo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Structural Studies ◽  
Γ Ray

Effects of Gamma Irradiation on Optical Properties of Colloidal Nanocrystals

2007 ◽  
Vol 1038 ◽  
Author(s):  
Nathan J Withers ◽  
Krishnaprasad Sankar ◽  
Brian A. Akins ◽  
Tosifa A. Memon ◽  
Jiangjiang Gu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Gamma Irradiation ◽  
Irradiation Dose ◽  
Nanocrystalline Material ◽  
Light Output ◽  
Colloidal Nanocrystals ◽  
Photoluminescence Intensity ◽  
Photoluminescence Properties ◽  
Material Systems ◽  
Dose Radiation

AbstractThe effects of 137Cs gamma irradiation on photoluminescence properties, such as spectra, light output, and lifetime, of several types of colloidal nanocrystals have been investigated. Irradiation-induced damage testing was performed on CdSe/ZnS, LaF3:Eu, LaF3:Ce, ZnO, and PbI2 nanocrystals synthesized on a Schlenk line using appropriate solvents and precursors. Optical degradation of the nanocrystals was evaluated based on the measured dependence of their photoluminescence intensity on the irradiation dose. Radiation hardness varies significantly between various nanocrystalline material systems.

Surface and Composite Interface of Carbon Fiber Modified by Grafting of Diethanolamine

2009 ◽  
Vol 79-82 ◽  
pp. 497-500 ◽  
Author(s):  
Lei Chen ◽  
Zhi Wei Xu ◽  
Jia Lu Li ◽  
Xiao Qing Wu ◽  
Li Chen
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Irradiation Dose ◽  
Interlaminar Shear Strength ◽  
Epoxy Composites ◽  
Composite Interface ◽  
Γ Ray ◽  
Interlaminar Shear

The γ-ray co-irradiation method was employed to study the effect of diethanolamine modification on the surface of carbon fiber (CF) and the interfacial properties of CF/epoxy composites. Compared with the original carbon fiber, the surface of modified fibers became rougher. The amount of oxygen-containing functional groups was increased and the nitrogen element was detected after irradiation grafting. The interlaminar shear strength (ILSS) of composites reinforced by carbon fibers irradiated in diethanolamine solution was increased and then decreased as the irradiation dose increased. The ILSS of CF/epoxy composites was enhanced by 16.1% at 200kGy dose, compared with that of untreated one. The γ-ray irradiation grafting is expected to be a promising method for the industrialized modification of carbon fibers.

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