{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T23:19:45Z","timestamp":1780701585543,"version":"3.54.1"},"reference-count":49,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,5,8]],"date-time":"2025-05-08T00:00:00Z","timestamp":1746662400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003725","name":"Korean government (MEST)","doi-asserted-by":"publisher","award":["NRF 2020R1I1A3070451"],"award-info":[{"award-number":["NRF 2020R1I1A3070451"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Protective garments for the medical radiation shielding of healthcare professionals must ensure flexibility and shielding performance. As such, process technologies for density enhancement are required when manufacturing shielding sheets to ensure the reproducibility of flexibility and shielding performance. Although previous efforts commonly reduced particle size to minimize porosity, nanoparticle production cost is significant. Therefore, this study aimed to improve the density of the shielding sheet by controlling the spacing between internal particles. The proposed improvement method is based on polydisperse particle packing. Particle sizes can be adjusted using process techniques such as sintering, pressing, and mixing. The study materials used are tungsten and bismuth oxide (eco-friendly alternatives to lead), with polyethylene as the polymer matrix. First, the shielding performance improved by 4% in the sintering process when the tungsten content reached 90 weight percent (wt%). The solvent removal process, used to eliminate the solvent added for polymer utilization, increased the density by 13.18%; however, it was lower than that of the compression process. The shielding performance improved by approximately 10% in the compression molding process when the tungsten content was 90 wt%. This study confirms that optimizing density enhancement strategies for radiation shielding materials can significantly improve shielding performance.<\/jats:p>","DOI":"10.3390\/ma18102174","type":"journal-article","created":{"date-parts":[[2025,5,8]],"date-time":"2025-05-08T09:58:09Z","timestamp":1746698289000},"page":"2174","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Development of a Process Technology to Improve the Internal Particle Density and Enhance the Performance of Medical Radiation Shielding Materials"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6637-736X","authenticated-orcid":false,"given":"Seon-Chil","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Biomedical Engineering, School of Medicine, Keimyung University, 1095 Dalgubeol-daero, Daegu 42601, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1148\/radiol.2020192256","article-title":"Patient exposure from radiologic and nuclear medicine procedures in the United States: Procedure volume and effective dose for the period 2006\u20132016","volume":"295","author":"Mettler","year":"2020","journal-title":"Radiology"},{"key":"ref_2","first-page":"445","article-title":"Radiation Effects and Protection for Technologists and Other Health Care Professionals","volume":"92","author":"Smith","year":"2021","journal-title":"Radiol. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"108439","DOI":"10.1016\/j.radphyschem.2019.108439","article-title":"Conventional and new lead-free radiation shielding materials for radiation protection in nuclear medicine: A review","volume":"165","author":"AbuAlRoos","year":"2019","journal-title":"Radiat. Phys. Chem."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.ejmp.2020.08.017","article-title":"Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine","volume":"78","author":"AbuAlRoos","year":"2020","journal-title":"Phys. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"109437","DOI":"10.1016\/j.radphyschem.2021.109437","article-title":"X-ray spectra and gamma factors from 70 to 120 kV X-ray tube voltages","volume":"184","year":"2021","journal-title":"Radiat. Phys. Chem."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"126646","DOI":"10.1016\/j.colsurfa.2021.126646","article-title":"Increase in linear attenuation coefficient by changing crystal structure of materials for radiation shielding and biomedical devices safety","volume":"622","author":"Halliwell","year":"2021","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2057","DOI":"10.1007\/s10311-021-01189-9","article-title":"Polymeric composite materials for radiation shielding: A review","volume":"19","author":"More","year":"2021","journal-title":"Environ. Chem. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e02478","DOI":"10.1016\/j.heliyon.2019.e02478","article-title":"Perceptions on radioprotective garment usage and underlying reasons for non-adherence among medical radiation workers from public hospitals in a middle-income Asian setting: A qualitative exploration","volume":"5","author":"Ridzwan","year":"2019","journal-title":"Heliyon"},{"key":"ref_9","first-page":"44","article-title":"Use of out-of-field contact shielding on patients in medical imaging: A review of current guidelines, recommendations and legislative documents","volume":"86","author":"Dabin","year":"2011","journal-title":"Phys. Med."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Shahzad, K., Kausar, A., Manzoor, S., Rakha, S.A., Uzair, A., Sajid, M., Arif, A., Kjan, A.F., Diallo, A., and Ahmad, I. (2022). Views on radiation shielding efficiency of polymeric composites\/nanocomposites and multi-layered materials: Current state and advancements. Radiation, 3.","DOI":"10.3390\/radiation3010001"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lopresti, M., Alberto, G., Cantamessa, S., Cantino, G., Conterosito, E., Palin, L., and Milanesio, M. (2020). Light weight, easy formable and non-toxic polymer-based composites for hard x-ray shielding: A theoretical and experimental study. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21030833"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Li, Z., Zhou, W., Zhang, X., Gao, Y., and Guo, S. (2021). High-efficiency, flexibility and lead-free X-ray shielding multilayered polymer composites: Layered structure design and shielding mechanism. Sci. Rep., 11.","DOI":"10.1038\/s41598-021-83031-4"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2547","DOI":"10.1016\/j.ceramint.2020.09.100","article-title":"The impact of PbF2 on the ionizing radiation shielding competence and mechanical properties of TeO2\u2013PbF2 glasses and glass-ceramics","volume":"47","author":"Rammah","year":"2021","journal-title":"Ceram. Int."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2123","DOI":"10.1016\/j.rinp.2019.01.094","article-title":"Photon and neutron shielding characteristics of samarium doped lead alumino borate glasses containing barium, lithium and zinc oxides determined at medical diagnostic energies","volume":"12","author":"Almatari","year":"2019","journal-title":"Results Phys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"124084","DOI":"10.1016\/j.matchemphys.2020.124084","article-title":"Bismuth Oxide Films for X-ray shielding: Effects of particle size and structural morphology","volume":"260","author":"Yu","year":"2021","journal-title":"Mater. Chem. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"7471","DOI":"10.1021\/acsanm.1c01475","article-title":"Lightweight bismuth titanate (Bi4Ti3O12) nanoparticle-epoxy composite for advanced lead-free X-ray radiation shielding","volume":"4","author":"Yu","year":"2021","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"5201","DOI":"10.1016\/j.net.2024.07.027","article-title":"Al\u2013B4C-(Gd, Gd2O3) composite materials: Synthesis and characterization for neutron shielding applications","volume":"56","author":"Gaylan","year":"2024","journal-title":"Nucl. Eng. Technol."},{"key":"ref_18","unstructured":"Safari, A., Rafie, P., Taeb, S., Najafi, M., and Mortazavi, S.M.J. (2024). Development of lead-free materials for radiation shielding in medical settings: A review. J. Biomed. Phys. Eng., 14."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Khasanov, O., Dvilis, E., Petyukevich, M., and Shamanin, I. (2020, January 14\u201316). Metal-ceramic nanocomosite for radiation shielding of electronics. Proceedings of the 2020 7th International Congress on Energy Fluxes and Radiation Effects (EFRE), Tomask, Russia.","DOI":"10.1109\/EFRE47760.2020.9242100"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"108920","DOI":"10.1016\/j.radphyschem.2020.108920","article-title":"Radiation shielding properties of Nd0.6Sr0.4Mn1\u2212yNiyO3 substitute with different concentrations of nickle","volume":"174","author":"Hamad","year":"2020","journal-title":"Radiat. Phys. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1016\/j.pnucene.2019.03.033","article-title":"Study on gamma shielding polymer composites reinforced with different sizes and proportions of tungsten particles using MCNP code","volume":"115","author":"Alavian","year":"2019","journal-title":"Prog. Nucl. Energy"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4347","DOI":"10.1016\/j.jmrt.2024.04.138","article-title":"Isostatic hot-pressed tungsten radiation shields against gamma radiation","volume":"30","author":"Tishkevich","year":"2024","journal-title":"J. Mater. Res. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Daneshvar, H., Milan, K.G., Sadr, A., Sedighy, S.H., Malekie, S., and Mosayebi, A. (2021). Multilayer radiation shield for satellite electronic components protection. Sci. Rep., 11.","DOI":"10.1038\/s41598-021-99739-2"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"108","DOI":"10.3329\/bjnm.v21i2.40361","article-title":"Evaluation of gamma radiation attenuation characteristics of different type shielding materials used in nuclear medicine services","volume":"21","author":"Mollah","year":"2018","journal-title":"Bangladesh J. Nucl. Med."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2508","DOI":"10.1016\/j.matpr.2020.04.610","article-title":"Development of bismuth sodium borate glasses for radiation shielding material","volume":"43","author":"Cheewasukhanont","year":"2021","journal-title":"Mater. Today Proc."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1021\/ed039p333","article-title":"The beer-lambert law","volume":"39","author":"Swinehart","year":"1962","journal-title":"J. Chem. Educ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.radphyschem.2017.02.054","article-title":"Mass attenuation coefficients of X-rays in different barite concrete used in radiation protection as shielding against ionizing radiation","volume":"140","author":"Junior","year":"2017","journal-title":"Radiat. Phys. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.compscitech.2017.03.002","article-title":"Radiation shielding property of structural polymer composite: Continuous basalt fiber reinforced epoxy matrix composite containing erbium oxide","volume":"143","author":"Li","year":"2017","journal-title":"Compos. Sci. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"24491","DOI":"10.1039\/D3RA04509A","article-title":"Heavy alloy based on tungsten and bismuth: Fabrication, crystal structure, morphology, and shielding efficiency against gamma-radiation","volume":"13","author":"Tishkevich","year":"2023","journal-title":"RSC Adv."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Mushtaq, Q., Saddique, Z., Javaid, A., Latif, S., Imran, M., and Mitu, L. (2024). Fabrication of Fuel Cell Involving Bismuth-Based Components for Efficient and Cost-effective Strategies. Comments on Inorganic Chemistry, Taylor & Francis.","DOI":"10.1080\/02603594.2024.2417272"},{"key":"ref_31","first-page":"e20240124","article-title":"Polyethylene of raised temperature resistance (PE-RT) nanocomposites reinforced with graphene oxide for application in flexible pipelines","volume":"27","author":"Cruz","year":"2024","journal-title":"Mater. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3939","DOI":"10.1016\/j.actamat.2010.03.033","article-title":"Investigation on sintering mechanism of nanoscale tungsten powder based on atomistic simulation","volume":"58","author":"Moitra","year":"2010","journal-title":"Acta Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"10730","DOI":"10.1021\/jp4008009","article-title":"Production of high-concentration graphene dispersions in low-boiling-point organic solvents by liquid-phase noncovalent exfoliation of graphite with a hyperbranched polyethylene and formation of graphene\/ethylene copolymer composites","volume":"117","author":"Xu","year":"2013","journal-title":"J. Phys. Chem. C"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"461","DOI":"10.17946\/JRST.2017.40.3.14","article-title":"Preliminary study for development of low dose radiation shielding material using liquid silicon and metalic compound","volume":"40","author":"Jang","year":"2017","journal-title":"J. Radiol. Sci. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Quadrini, F., Patrizii, G., Proietti, A., Iorio, L., Bellisario, D., and Santo, L. (2024). Compression Molding of Low-Density Polyethylene Matrix\/Glass-Fiber-Reinforced Thick Laminates. Polymers, 16.","DOI":"10.3390\/polym16192722"},{"key":"ref_36","unstructured":"(2018). Rubber, Vulcanized or Thermoplastic\u2014Determination of Density (Standard No. ISO 2781)."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Kokalis, C.C., Giasafakis, C.D., Kontargyri, V.T., and Gonos, I.F. (2021, January 21\u201326). Hydrophobicity and density measurements on new and field aged medium voltage composite insulators. Proceedings of the 22nd International Symposium on High Voltage Engineering (ISH 2021), IET, Xi\u2019an, China.","DOI":"10.1049\/icp.2022.0167"},{"key":"ref_38","unstructured":"(2022). Rubber, Vulcanized or Thermoplastic\u2014Determination of Tensile Stress-Strain Properties (Standard No. KS M ISO 37)."},{"key":"ref_39","unstructured":"(2018). Medical X-Ray Protective Aprons (Standard No. KS P 6023)."},{"key":"ref_40","first-page":"79","article-title":"Analysis of half value layer (HVL), Tenth value layer (TVL) and mean free path (MFP) of some oxides in the energy range of 122KeV to 1330KeV","volume":"9","author":"Dahinde","year":"2019","journal-title":"Indian J. Sci. Res."},{"key":"ref_41","unstructured":"(2005). Method for Testing the Stability of Food Packaging Materials (Standard No. KS A 4025)."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1269","DOI":"10.1016\/0020-708X(82)90248-4","article-title":"Photon mass attenuation and energy-absorption coefficients","volume":"33","author":"Hubbell","year":"1982","journal-title":"Int. J. Appl. Radiat. Isot."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3608","DOI":"10.1016\/j.net.2024.04.012","article-title":"Enhancing X-ray radiation protection with novel liquid silicone rubber composites: A promising alternative to lead aprons","volume":"56","author":"Abdullah","year":"2024","journal-title":"Nucl. Eng. Technol."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Manikandan, R., and Raja Annamalai, A. (2022). Tungsten heavy alloys processing via microwave sintering, spark plasma sintering, and additive manufacturing: A review. Processes, 10.","DOI":"10.3390\/pr10112352"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"33495","DOI":"10.1016\/j.ceramint.2023.07.207","article-title":"Influence of bismuth oxide as a sintering aid on the densification of cold sintering of zirconia","volume":"49","author":"Bhootpur","year":"2023","journal-title":"Ceram. Int."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1080\/10408436.2010.525197","article-title":"Coarsening in sintering: Grain shape distribution, grain size distribution, and grain growth kinetics in solid-pore systems","volume":"35","author":"German","year":"2010","journal-title":"Crit. Rev. Solid State Mater. Sci."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Zhang, H., and Lin, S. (2023). Research progress with membrane shielding materials for electromagnetic\/radiation contamination. Membranes, 13.","DOI":"10.3390\/membranes13030315"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Gouda, M.M., Osman, A.F., Awad, R., and Badawi, M.S. (2024). Enhanced radiation shielding efficiency of polystyrene nanocomposites with tailored lead oxide nanoparticles. Sci. Rep., 14.","DOI":"10.1038\/s41598-024-69510-4"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"650","DOI":"10.2514\/1.T6223","article-title":"Consideration of backscatter radiation from galactic cosmic rays in spacecraft shielding design","volume":"35","author":"Warden","year":"2021","journal-title":"J. Thermophys. Heat. 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