High Performance Dual Ballistic and Thermal Neutrons Shields From Kevlar Fibers Reinforced Epoxy/B4C Hybrid Composites

Abstract

Targeting the development of advanced lightweight thermal and ballistic neutrons shields, a new hybrid composite was developed, for the first time, from Kevlar fibers, epoxy and boron carbide (B4C) particles. Kevlar fibers, as one of the strongest polymeric fillers, possess a high proportion of low Z atoms highly suitable for moderating neutrons. Meanwhile, these fibers can provide an additional efficient protection against high velocity projectiles. The B4C particles were added in various amounts, mainly for their excellent absorption of thermal neutrons. The nuclear shielding tests were performed at NUR research reactor using an optimized experimental setup. The obtained results confirmed the high shielding efficiency of all the developed materials. Meanwhile, the best performance was recorded at B4C amount of 20 wt.% with a macroscopic cross-section (Σ) of with a 3.638 cm−1 equivalent to a mean free path (λ) of 0.191 cm. The obtained results were compared with the most performant available shields and the data confirmed that superiority of the developed materials.

Preparation of Nano-PbWO4 Particles by Polymaleic Acid Modification: A Highly Filled Nonwoven Membrane Used To Improve the Wearing Comfort and Radiation Safety of γ-ray Protection Products

“…This occurs because the filler lacks strong interfacial interaction with PVA, making it challenging for the filler to disperse evenly and maintain good compatibility with the composite. 36,37 In this study, poly(maleic acid) (PMA) was used to reduce the particle size of PWO particles and modify their surfaces to prepare nano-PWO@PMA particles. Additionally, electrospinning technology was employed to fabricate a series of PWO@PMA/PVA nonwoven membranes.…”

“…It is generally believed that inorganic particles such as hydroxyapatite and boron nitride can enhance their interaction with PVA by reducing the particle diameter and modifying the surface, thereby improving spinning stability. , However, highly filled PVA-based composites often exhibit defects, such as filler agglomeration and voids. This occurs because the filler lacks strong interfacial interaction with PVA, making it challenging for the filler to disperse evenly and maintain good compatibility with the composite. , …”