Document Type: Original Research

Authors

1 Department of Nuclear Engineering, Islamic Azad University, Arsanjan Branch, Arsanjan, Iran

2 Radiation Application Research School, Nuclear Science and Technology Research Institute, Karaj, Iran

3 Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

Background: In recent years, there has been an increased interest toward non-lead radiation shields consisting of small-sized filler particles doped into polymer matrices. In this paper, we study a new polyvinyl alcohol (PVA)/WO3 composite in the presence of high-energy gamma photons through simulation via the Monte Carlo N-Particle (MCNP) simulation code.
Material and Methods: An MCNP geometry was first designed in the software based on real-life conditions, and the generated geometry was validated by calculating the mass attenuation coefficient and making relative comparisons with standard tables. Using the lattice card in the MCNP input file, WO3 was considered as a filler dispersed in a PVA polymer at sizes of 10 µm and 30 nm with a weight concentration of 50 wt%. By defining 106-photons emitted from point sources corresponding to 662, 778, 964, 1112, 1170, 1130 and 1407 keV energy levels, and the F4 tally used to estimate the cell average flux, the values for mass attenuation coefficient and half-value layer (HVL) were calculated.
Results: The results show that PVA/WO3 composite can be considered to shield X and γ-rays in the mentioned energies. However, nano-WO3 has a better ability to shield in comparison with the micro-WO3 fillers. The differences in attenuation changed at different energy levels, ascribed to the dominance of pair production occurrence and photon interactions in the composite, which was in good agreement with previous studies.
Conclusion: Our finding showed that the composite can be considered as a lead-free shielding material.

Keywords

  1. Chao KS. Protection of salivary function by intensity-modulated radiation therapy in patients with head and neck cancer. Semin Radiat Oncol. 2002;12:20-5. Doi: 10.1053/srao.2002.31359 .PubMed PMID: 11917280.
  2. Nambiar S, Yeow JT. Polymer-composite materials for radiation protection. ACS Appl Mater Interfaces. 2012;4:5717-26. doi: 10.1021/am300783d. PubMed PMID: 23009182.
  3. Khan FM, Gibbons JP. Khan’s the physics of radiation therapy: Lippincott Williams & Wilkins; 2014.
  4. Yue K, Luo W, Dong X, Wang C, Wu G, Jiang M, et al. A new lead-free radiation shielding material for radiotherapy. Radiat Prot Dosimetry. 2009;133:256-60. doi: 10.1093/rpd/ncp053. PubMed PMID: 19329510.
  5. Chen L, Xu Y, Zhang F, Yang Q, Yuan J. An effective intervention to improve the cleanliness of medical lead clothes in an orthopedic specialized hospital. Am J Infect Control. 2016;44:e269-e70. doi: 10.1016/j.ajic.2016.06.002. PubMed PMID: 27430735.
  6. Chang L, Zhang Y, Liu Y, Fang J, Luan W, Yang X, et al. Preparation and characterization of tungsten/epoxy composites for γ-rays radiation shielding. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 2015;356:88-93. doi: 10.1016/j.nimb. 2015.04.062.
  7. Song C, Zheng J, Zhang Q-P, Li Y-T, Li Y-J, Zhou Y-L. Numerical simulation and experimental study of PbWO4/EPDM and Bi2WO6/EPDM for the shielding of γ-rays. Chinese Physics C. 2016;40:089001. doi: 10.1088/1674-1137/40/8/089001.
  8. Malekie S, Hajiloo N. Comparative study of micro and nano size WO3/E44 epoxy composite as gamma radiation shielding using MCNP and experiment. Chinese Physics Letters. 2017;34:108102. doi: 10.1088/0256-307x/34/10/108102.
  9. Tekin H, Sayyed M, Altunsoy E, Manici T. Shielding properties and effects of WO3 and PbO on mass attenuation coefficients by using MCNPX code. Dig J Nanomater Biostruct. 2017;12:861-7.
  10. Tekin HO, Singh V, Manici T. Effects of micro-sized and nano-sized WO3 on mass attenauation coefficients of concrete by using MCNPX code. Appl Radiat Isot. 2017;121:122-5. doi: 10.1016/j.apradiso.2016.12.040.
  11. Mostafa A, Issa SA, Sayyed M. Gamma ray shielding properties of PbO-B2O3-P2O5 doped with WO3. Journal of Alloys and Compounds. 2017;708:294-300. doi: 10.1016/j.jallcom.2017.02.303.
  12. Mesbahi A, Ghiasi H. Shielding properties of the ordinary concrete loaded with micro- and nano-particles against neutron and gamma radiations. Appl Radiat Isot. 2018;136:27-31. doi: 10.1016/j.apradiso.2018.02.004. PubMed PMID: 29455112.
  13. Aghamiri M, Mortazavi S, Tayebi M, Mosleh-Shirazi M, Baharvand H, Tavakkoli-Golpayegani A, et al. A novel design for production of efficient flexible lead-free shields against X-ray photons in diagnostic energy range. Journal of Biomedical Physics and Engineering. 2011;1:18-21.
  14. DeMerlis CC, Schoneker DR. Review of the oral toxicity of polyvinyl alcohol (PVA). Food Chem Toxicol. 2003;41:319-26. doi: 10.1016/s0278-6915(02)00258-2 .PubMed PMID: 12504164.
  15. Baker MI, Walsh SP, Schwartz Z, Boyan BD. A review of polyvinyl alcohol and its uses in cartilage and orthopedic applications. J Biomed Mater Res B Appl Biomater. 2012;100:1451-7. doi: 10.1002/jbm.b.32694. PubMed PMID: 22514196.
  16. Guo Z, Zhang D, Wei S, Wang Z, Karki AB, Li Y, et al. Effects of iron oxide nanoparticles on polyvinyl alcohol: interfacial layer and bulk nanocomposites thin film. Journal of Nanoparticle Research. 2010;12:2415-26. doi: 10.1007/s11051-009-9802-z.
  17. Pai S, Crasta V, Shreeprakash B, editors. Studies of the effect of nanoparticle dopants and blending of different polymers on Physical, Electrical, Optical and Micro structural properties of PVA-a Review. 24-26 July 2013. Chennai: International Conference on Advanced Nanomaterials & Emerging Engineering Technologies; 2013. doi: 10.1109/icanmeet.2013.6609388.
  18. Singh H, Kumar D, Sawant KK, Devunuri N, Banerjee S. Co-doped ZnO–PVA Nanocomposite for EMI Shielding. Polymer-Plastics Technology and Engineering. 2016;55:149-57. doi: 10.1080/03602559.2015.1070869.
  19. Amin G, Abd-El Salam M. Optical, dielectric and electrical properties of PVA doped with Sn nanoparticles. Materials Research Express. 2014;1:025024. doi: 10.1088/2053-1591/1/2/025024.
  20. Rithin Kumar N, Crasta V, Bhajantri RF, Praveen B. Microstructural and mechanical studies of PVA doped with ZnO and WO3 composites films. Journal of Polymers. 2014;2014. doi: 10.1155/2014/846140.
  21. Voranuch T, Akapong P, Naris B, Sarawut J. BaSO4/polyvinyl alcohol composites for radiation shielding. Appl Mech Mater. 2015;804:3-6. doi: 10.4028/www.scientific.net/amm.804.3.
  22. Singh R, Kulkarni SG, Channe SS. Thermal and mechanical properties of nano-titanium dioxide-doped polyvinyl alcohol. Polymer bulletin. 2013;70:1251-64. doi: 10.1007/s00289-012-0846-3.
  23. Pellowitz D. MCNPX User’s Manual, version 2.6. 0. Los Alamos Report No LA CP. 2007;2:408.
  24. Cember H, Johnson TE, Alaei P. Introduction to health physics. Med Phys. 2008;35:5959.
  25. Hubbell JH, Seltzer SM. Tables of X-ray mass attenuation coefficients and mass energy-absorption coefficients 1 keV to 20 MeV for elements Z= 1 to 92 and 48 additional substances of dosimetric interest. National Inst. of Standards and Technology-PL, Gaithersburg, MD (United States). Ionizing Radiation Div, 1995 May. Report No: PB-95-220539/XAB; NISTIR-5632. doi: 10.6028/nist.ir.5632.
  26. Boone JM, Chavez AE. Comparison of x-ray cross sections for diagnostic and therapeutic medical physics. Med Phys. 1996;23:1997-2005. doi: 10.1118/1.597899. PubMed PMID: 8994164.
  27. Yu D, Shu-Quan C, Hong-Xu Z, Chao R, Bin K, Ming-Zhu D, et al. Effects of WO3 particle size in WO3/epoxy resin radiation shielding material. Chinese Physics Letters. 2012;29:108102. doi: 10.1088/0256-307x/29/10/108102.
  28. Noor Azman NZ, Siddiqui SA, Hart R, Low IM. Effect of particle size, filler loadings and x-ray tube voltage on the transmitted x-ray transmission in tungsten oxide-epoxy composites. Appl Radiat Isot. 2013;71:62-7. doi: 10.1016/j.apradiso.2012.09.012. PubMed PMID: 23123305.