Opto-structural characterization of proton (3MeV) irradiated polycarbonate and polystyrene

Singh, Lakhwant; Samra, Kawaljeet Singh

doi:10.1016/j.radphyschem.2007.05.009

Cited by 34 publications

(13 citation statements)

References 13 publications

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“…[32] for PA, PS, PE and PMMA. The energy band gap values are from Refs [33] (PA), [34] (PS), [35] (PE) and [36,37] as a model the expansion in Drude-Lindhard type oscillators [30] Im…”

Section: Surface Excitation Parameter From Queelsmentioning

confidence: 99%

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Surface excitation parameter for selected polymers

Pauly¹,

Tougaard²

2008

Surface & Interface Analysis

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The surface excitation parameter (SEP) is theoretically determined for different polymers, namely, polyethylene (PE), polystyrene (PS), polyacetylene (PA) and polymethyl methacrylate (PMMA), for electron energies between 300 and 5000 eV and for angles between 0 and 70 o to the surface normal. We use our previous definition of SEP as the change in excitation probability of an electron caused by the presence of the surface in comparison with an electron moving in an infinite medium. The calculations are performed within the dielectric response theory by means of the QUEELS-ε(k, ω)-REELS software determining the energy-differential inelastic electron scattering cross-sections for reflection-electron-energy-loss spectroscopy (REELS). More precisely, the volume component for an infinite medium is subtracted from the calculated REELS cross-section and in this way the surface excitation component of the cross-section is determined and the SEP calculated. We find that the presence of an energy band gap reduces the SEP values compared to those for metals, and this decrease is larger for polymers with larger gaps.

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“…[32] for PA, PS, PE and PMMA. The energy band gap values are from Refs [33] (PA), [34] (PS), [35] (PE) and [36,37] as a model the expansion in Drude-Lindhard type oscillators [30] Im…”

Section: Surface Excitation Parameter From Queelsmentioning

confidence: 99%

“…[31] These parameters for PE, PS, PA and PMMA are essentially taken from Ref. [32] , while energy band gap values, E G , are from Refs [33] (PA), [34] (PS), [35] (PE) and [36,37] (PMMA). All parameters are listed in Table 1 and the ELF for PE, PS, PA and PMMA are displayed in Fig.…”

Section: Surface Excitation Parameter From Queelsmentioning

confidence: 99%

Surface excitation parameter for selected polymers

Pauly¹,

Tougaard²

2008

Surface & Interface Analysis

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“…Many processes, such as the production of primary and secondary radicals, lead to the formation of double bonds, the transformation of C−C bonds, and auto-oxidation occurs in the presence of oxygen. These reactions depend on the proton dose (5). For polycarbonates irradiated with a 200 keV proton beam, the refractive index was found to be an increasing function of the dose (6).…”

Section: Introductionmentioning

confidence: 95%

Thermal, electrical and optical properties of proton-irradiated Makrofol DE 7-2 nuclear track detector

Nouh

Abdelsalam

Radwan

et al. 2011

Radiation Effects and Defects in Solids

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Samples from sheets of the polymeric material Makrofol DE 7-2 have been exposed to 1 MeV protons of fluences in the range 2.5 × 10 13 -5 × 10 15 p/cm 2 . The resultant effect of proton irradiation on the thermal properties of Makrofol has been investigated using thermogravimetric analysis and differential thermal analysis (DTA). The onset temperature of decomposition T o and the activation energy of thermal decomposition E a were calculated, and the results indicated that the Makrofol detector decomposes in one weight loss stage. Also, the proton irradiation in the fluence range 7.5 × 10 13 -5 × 10 15 p/cm 2 led to a more compact structure of Makrofol polymer, which resulted in an improvement in its thermal stability with an increase in the activation energy of thermal decomposition. The variation of transition temperatures with proton fluence has been determined using DTA. The Makrofol thermograms were characterized by the appearance of an endothermic peak due to the melting of the crystalline phase. The melting temperature of the polymer, T m , was investigated to probe the crystalline domains of the polymer. At a fluence range of 7.5 × 10 13 -5 × 10 15 p/cm 2 , the defect generated destroys the crystalline structure, thus reducing the melting temperature. In addition, the V -I characteristics of the polymer samples were investigated. The electrical conductivity was decreased with the increasing proton fluence up to 5 × 10 15 p/cm 2 . Further, the refractive index, transmission of the samples and any color changes were studied. The color intensity E was greatly increased with the increasing proton fluence and was accompanied by a significant increase in the red and yellow color components.

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“…The interaction of SHI's with a polymer leads to alteration in its structural and chemical composition by processes like main chain scission, intermolecular cross-linking, radical formation [9], generation of unsaturated double bonds and loss of unstable shards [10][11][12]. The alterations initiated by irradiation in a polymer results in a gradational increase in optical absorbance [13], creation of chromophoric groups [14] and double and triple bonds and formation of three dimensional carbon networks (i.e. carbon clusters [15]) as well as a step by step change in phase [16].…”

Section: Introductionmentioning

confidence: 99%

Induced Electronic and Thermal Effects of 86 MeV Nickel Ions in Bisphenol-A Polycarbonate

Devi

Samra

Singh

2016

Journal of Macromolecular Science, Part B

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Bisphenol-A polycarbonate films were irradiated with 86 MeV swift heavy nickel ions at varying fluences, ranging from 110 11 to 110 13 ions cm 2 , under vacuum at room temperature, to analyze the induced electrical and thermal modifications. AC conductivity measurements and UV-visible spectroscopy, Fourier transform infra-red (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques were applied to analyze the changes. A significant, exponential increase in conductivity at higher frequency was observed with the increase of nickel ion fluence. UV-visible analysis corroborated the results of the AC conductivity measurement, revealing the increase in size of the carbon clusters embedded in the polymer network, with the increase of heavy ion fluence. FTIR analysis revealed the formation of alkene and alkyne end groups at higher doses, which further supported Downloaded by [University of Nebraska, Lincoln] at 02:20 15 June 2016 ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT 2 the suggestion that the variation in electrical properties induced by the ion irradiation of the polymer was due to development of a carbonaceous phase inside the polymer due to the irradiation. Thermal analysis, i.e. TGA and DSC patterns, showed that chain-scission was the leading phenomena in the heavy ion irradiated polycarbonate samples, resulting in degradation of their thermal stability.

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Opto-structural characterization of proton (3MeV) irradiated polycarbonate and polystyrene

Cited by 34 publications

References 13 publications

Surface excitation parameter for selected polymers

Surface excitation parameter for selected polymers

Thermal, electrical and optical properties of proton-irradiated Makrofol DE 7-2 nuclear track detector

Induced Electronic and Thermal Effects of 86 MeV Nickel Ions in Bisphenol-A Polycarbonate

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