Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-27T11:49:59.468Z Has data issue: false hasContentIssue false

ESR Detection of X-Ray-Induced Free Radicals in Crosslinked Silica Aerogels

Published online by Cambridge University Press:  21 June 2017

Benjamin M. Walters
Affiliation:
Department of Physics and Materials Science, University of Memphis, Memphis TN, 38152, U.S.A.
Ramón V. León
Affiliation:
Department of Statistics, Operations, and Management Science, University of Tennessee, Knoxville, TN, 37996, U.S.A.
Muhammad S. Jahan
Affiliation:
Department of Physics and Materials Science, University of Memphis, Memphis TN, 38152, U.S.A.
Firouzeh Sabri*
Affiliation:
Department of Physics and Materials Science, University of Memphis, Memphis TN, 38152, U.S.A.
*
Get access

Abstract

Aerogels are a promising material for aerospace applications and have recently been explored for biomedical applications also. In both environments, exposure to radiation is inevitable, such as from radiation in space or, radiation-based sterilization and tracking of implants. X-ray radiation, in particular, is of a concern. Here, polyurea-crosslinked silica aerogel (PCSA) samples were exposed to approximately 170- and 500-Gy X-irradiation at room temperature under varying environmental conditions and characterized using electron spin resonance (ESR) technique. Results obtained for PCSA were compared with those from polyether-ether ketone (PEEK) and ultra-high molecular weight polyethylene (UHMWPE) which served as benchmarks for this study. PEEK is known to be very radiation resistant, while UHMWPE is known to be less radiation resistant. All materials (PCSA, PEEK, and UHMWPE) were exposed to the same treatments and exposure conditions. Two exposure times were tested: 10 min and 30 min which corresponded to “low” and “high” conditions, as well as comparisons of nitrogen vs. air environments during exposure and post-exposure storage. Results showed significant quantities of free radicals produced in PCSA after exposure to X-irradiation which scaled with radiation dosage; quantities were in-between those produced in PEEK and UHMWPE. The storage conditions (air vs. nitrogen) also played an important role in the free radical levels detected and are reported in this study.

Type
Articles
Copyright
Copyright © Materials Research Society 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Premnath, V. et al., Biomaterials 17(18), 1741 (1996).CrossRefGoogle Scholar
Hossain, U.H. and Ensinger, W., Nucl. Instr. Meth. Phys. Res. B 365, 230 (2015).CrossRefGoogle Scholar
Pfeifer, Michael, Materials Enabled Designs, (Butterworth-Heinemann, Boston, MA, 2009), pp. 161187.Google Scholar
Dever, J. et al., Handbook of Environmental Degradation of Materials, (William Andrew Publishing, Norwich, NY, 2005), pp. 465501.Google Scholar
Walters, B., Master’s Thesis, University of Tennessee, 2014, http://trace.tennessee.edu/utk_gradthes/2859 (accessed Feb. 2, 2017)Google Scholar
Mahieux, Céline, Environmental Degradation of Industrial Composites (Elsevier Science, Oxford, 2006), pp. 137173.CrossRefGoogle Scholar
Jahan, M.S, et al., Radiat. Phys. Chem. 62(1), 141 (2001).Google Scholar
Jahan, M.S. and Walters, B.M., Radiat. Phys. Chem. 80(2), 281 (2011).Google Scholar
Jahan, M.S., UHMWPE Biomaterials Handbook, 3rd ed., (William Andrew Publishing, Oxford, 2016), pp. 668692.Google Scholar
Maleki, H. et al., Adv. Colloid Interface Sci. 236, 1 (2016).CrossRefGoogle Scholar
Sabri, F. et al. PLOS ONE 7(3), e33242 (2012).Google Scholar
Sabri, F., Marchetta, J., and Smith, K.M., Acta Astronaut 91, 173 (2013).Google Scholar
Allison, S.W. et al., Radiat. Phys. Chem. 135, 88 (2017).Google Scholar
Sahu, S.K. et al., Instr. Meth. Phys. Res. A 382(3), 441 (1996).Google Scholar
Luo, L., Cooper, A.T., and Fan, M., J. Hazard. Mater. 161(1), 175 (2009).CrossRefGoogle Scholar
Richards, R.M. et al., Phys. Chem. Chem. Phys., Faraday Trans. 5(19), 4299 (2003).CrossRefGoogle Scholar
Zeus Industrial Products, Inc., Technical Whitepaper: “Focus on: PEEK,” (2005).Google Scholar
Li, H.M. et al., IEEE Trans. Dielectr. Electr. Insul. 6(3), 295 (1999).Google Scholar
Sabri, F., et al., PLOS ONE 8(6), e66348 (2013).Google Scholar