Multifunctional melamine-sponge composites with reflection capsules for radiation shielding in nuclear environments

Abstract

This study focused on radiation shielding materials for nuclear applications, employing a vacuum-assisted impregnation method to optimise the microstructure and establish a synergistic shielding mechanism combining scattering and absorption. Specifically, melamine sponge (MS) is first modified using KH550 to form –NH₂ active sites on its pore surfaces. Subsequently, it is immersed in a composite solution to construct “reflective capsules”. Finally, gradient encapsulation is performed using polyborosiloxane and polyurethane. The results show that compared with pure MS, the tensile strength of this material doubles, the elongation increases by 179 %, and its shielding capabilities against 59.6 keV γ-rays and 0.025 keV thermal neutrons increase by 1442 % and 1593 % respectively, reaching 27.14 % and 43.35 %. Additionally, it has a photothermal peak temperature of 78.5 °C and stable thermal response. Furthermore, relying on the three-dimensional elastic network of the MS and the conductive pathway of MXene, the material achieves a piezoresistive coefficient of 5.27 kPa⁻¹, demonstrating potential for application as a pressure-sensitive sensor. Through microstructure design and functional integration, this work makes the material suitable for complex scenarios such as nuclear facility maintenance and emergency rescue.