Superiority of clay composite materials of bentonite intercalated with the bimetallic MOFs-Pb/Cu, and nano magnetite to enhance the gamma and neutron radiation shielding

Abstract

In this study, a series of ternary nanocomposite materials were developed by integrating bentonite clay with nano magnetite and bimetallic metal–organic frameworks (MOFs) based on Pb/Cu and tartaric acid as organic linker. These composites were synthesized in varying compositions and systematically evaluated through both experimental techniques and theoretical modeling for their gamma radiation shielding performance. The composites were formulated with fixed proportions of 40.0 % bentonite as a base material with varying ratios of MOFs and nano magnetite specifically: (60.0–X) % bimetallic Pb/Cu-MOFs and X% nano magnetite, where X = 45.0 %, 30.0 %, and 15.0 %. These formulations are denoted as [B₄₀MPC_XMG(60-X)]. Comprehensive characterization of the base material of bentonite, and the Pb/Cu-MOFs was conducted using FT-IR, Raman, XRD, XRF, and HR-TEM tests. The radiation shielding properties of the composites were then assessed using Monte Carlo simulation code (MC) and Phy-X software across a broad photon energy range (0.015–15.0 MeV). Key shielding parameters were calculated to evaluate the shielding effectiveness. The results revealed that the MOF-Pb/Cu content controls either the γ-radiation and neutron attenuation performance in the prepared B₄₀MPC_XMG_(60-X) nano-composites. The B₄₀MPC₄₅MG₁₅ sample exhibited the highest linear attenuation coefficient for gamma radiation among the prepared composites, along with the lowest values of H/TV_L. Additionally,the B₄₀MPC₃₀MG₃₀ sample demonstrated the highest fast neutron removal cross-section among the prepared composites. The B₄₀MPC₃₀MG₃₀ sample is recommended as the optimal composition for superior shielding performance against both gamma rays and neutrons.