Complex Radiation Shielding Properties of Polyethylene Nanocomposites with Tungsten Nanoparticle Attached Boron Nitride Nanosheets

There has recently been an increase in demand for complex radiation shielding (neutron and γ-ray shielding) in the atomic energy, aerospace, and medical fields. In contrast to neutron shielding, which uses neutron absorbing materials (B or Gd), γ-ray shielding mostly employs heavy metals such as Pb, Fe, and W. Heavy metals are difficult to disperse in the polymer matrix due to the density differential with the polymer. However, when these materials are present as nanoparticles attached on the surface of two-dimensional (2D) materials, nanoparticle aggregation is reduced due to the large surface area of 2D materials, which can assist in matrix dispersion.<br/>Herein, we prepared polyethylene (PE) nanocomposites incorporated with tungsten nanoparticles (W NPs) decorated on boron nitride nanosheets (BNNS) hybrids. The cross-sectional area of the reaction of W NPs was increased by uniformly attaching to the BNNS surface with interfacial chemical bonding. Furthermore, non-covalent functionalization of the hybrids leads to increase the dispersibility of the hybrids in the matrix. The W-BNNS/PE nanocomposites demonstrated improved mechanical characteristics and thermal conductivity due to the interfacial bonding between W and BNNS and the interconnection of W NPs. The nanocomposites provided excellent radiation shielding properties for neutron (4.80 cm²/g) and gamma (γ) ray (0.093 cm²/g) radiation; this confirmed its potential as a complex radiation shielding material.<br/><br/><b>Acknowledgement</b><br/>This work was supported by the Development of 100 nm sized tungsten based material out of scrap and tool manufacturing technology using scrap for precision machining (20011520) funded by the Ministry of Trade, Industry & Energy (MOTIE, Korea) and the National Research Foundation of Korean (NRF) grant funded by the Korea government (Ministry of Science and ICT) (2021R1F1A1058854) and the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government (MOTIE, 20217510100020, Development of platform process using common core and materialization technology for rare metal recovery from industrial low-grade waste liquid).