FT-IR investigations on effect of high doses of gamma radiation-induced damage to polystyrene and mechanism of formation of radiolysis products

Abstract

The present article focuses on the influence of gamma irradiation and post-irradiation storage conditions on FT-IR spectra of 1 mm thick polystyrene irradiated with 51, 77 and 129 kGy. The increase in amplitude corresponding to 3600, 3400 and 2100 cm stretching frequencies clearly showing the formation of O-H and C=O bonds (~ 25%). On prolonged storage (2160 h) in the dark, there is an increase in O-H group (~ 28%). The electron cloud facilitates the formation of hydroxyl group in irradiated polystyrene. The post-irradiation treatment with heat conversely showed a reduction of O-H, C-H and C=O (9-16%) groups due to radical-radical recombination at higher temperatures and light intensities. This investigation finds its applications in memory devices, optical sensors, radiation dosimetry and different space and radiation facilities.

Sterilization of polypropylene membranes of facepiece respirators by ionizing radiation

“…No peaks are missing and no peak shifts were observed, confirming that the iPP retains its crystal structure even after gamma-ray or e-beam irradiation [ 29 , 30 ]. Although some studies showed [ 31 , 32 ] that gamma-ray irradiation forms hydroxyl (OH) and carbonyl (C=O) groups on polymers such as iPP, we did not observe any peaks corresponding to these groups at any dose [ 33 ].

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A detailed investigation of N95 respirator sterilization with dry heat, hydrogen peroxide, and ionizing radiation

“…In addition, no chemical changes were observed in Raman analysis of gamma-irradiated facemasks up to 25 kGy. Although few studies show that >50 kGy gamma irradiation forms carbonyl and hydroxyl groups in iPP fiber, 70 however, in the present study, corresponding peaks were not present, which is in line with other work. 21

Figure 2.Raman spectra of pristine and sterilized filter layer of the respirators.

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The triple action of sulfuric acid on the preparation of carbon-based solid acid from waste toner and its application

“…These indicate the presence of polystyrene (PS) in the waster toner. 34 In addition, the asymmetric stretching vibration and symmetrical deformation vibration of C-H in methyl groups appear at 2956 cm À1 and 1396 cm À1 , and C-H out-plane deformation vibration of terminal olefin is also observed at 906 cm À1 . 35 In addition, CQO strong stretching vibration at 1723 cm À1 , 10 and C-O asymmetric and symmetric stretching vibrations at 1261 cm À1 and 1157 cm À1 originate from ester groups.…”