Electronic Theses and Dissertations

Identifier

6186

Author

Saghar Gomrok

Date

2018

Date of Award

7-19-2018

Document Type

Thesis

Degree Name

Master of Science

Major

Physics

Concentration

Materials Science

Committee Chair

Muhammad Shah Jahan

Committee Member

Firouzeh Sabri

Committee Member

Xiao Shen

Abstract

This research project focuses on the effects of vitamin E on free radicals and thermoluminescence of 10-years old shelf-stored samples with different concentrations of vitamin E. Two spectroscopy methods were used to analyze the behavior of the free radicals in presence of vitamin E in old samples, Electron Spin Resonance (ESR) spectroscopy and Thermally Simulated Luminescence (TSL) spectroscopy. The experiments were performed on three different groups of UHMWPE. One group of samples includes vitamin E doped samples and non-vitamin E samples, both non-irradiated, which were stored in open air at room temperature (23°C) for more than 10 years. In this group, samples got irradiated with X-ray after 10 years of shelf-storage. In the second group of samples, vitamin E containing GUR 1020 solid samples were gamma-irradiated (30 kGy) more 10 years ago and have been stored in open air at room temperature (23°C). In the last group, non-irradiated samples doped with vitamin E and also non-irradiated non-vitamin E samples were forced to oxidized using thermal oxidation. Then samples were tested with TSL spectrometer. ESR analysis was performed using an in-house created software and TSL analysis was performed using PeakFit v4. The ultimate goal of this research project is to determine the long-term effects of vitamin E upon the production of free radicals during sterilization with gamma-ray and X-ray. In addition, another objective is to determine whether or not vitamin E had any anti-oxidation effect on the free-radical induced oxidation of sterilized UHMWPE during shelf-storage in a room environment, after a long time (more than 10 years).

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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