Boracic polyethylene/polyethylene wax blends and open-cell nickel foams as neutron-shielding composite

Abstract

This work shows that mechanical properties, thermal conductivity, and secondary gamma-ray shielding ability can be significantly improved when open-cell nickel foams are embedded into the shielding composites. The boracic polyethylene/polyethylene wax blends and open-cell nickel foam composites (PPNM) are designed and prepared by permeating homogeneous mixed melt fillers into open-cell nickel foams. The ratio of polyethylene and polyethylene wax is investigated to achieve higher filling rate. The quasi-static compressive response of PPNMs and polyethylene/polyethylene wax blends is measured, and the crystallization properties are studied by differential scanning calorimetry. The neutron and secondary gamma-ray shielding abilities of PPNMs are also simulated based on Monte Carlo particle transport method. Results show that the compression strength of PPNMs with boron carbide is slightly improved when compared with polyethylene/polyethylene wax blends. The nickel foams in PPNM composites improve the energy-absorbing efficiency by 30%. The thermal conductivity of PPNMs is 300% higher than polyethylene/polyethylene wax. The calculated results show that neutron-shielding abilities of PPNMs increase as content of boron carbide increases. Moreover, secondary gamma-ray shielding ability of PPNMs containing boron carbide is obviously higher than polyethylene/polyethylene wax. The PPNMs containing boron carbide neutron-shielding materials are proved to have good thermal conductivity, mechanical properties, and radiation-shielding ability.

Gamma irradiation, thermal conductivity, and phase change tests of the cement‐hyperbranched poly amino‐ester‐block‐poly cabrolactone‐polyurathane plaster‐lead oxide and arsenic oxide composite for development of radiation shielding material

“…However, as can be seen from the results, the dominant effect is the polymer. In terms of thermal conductivity, lead is a more conductive material than components such as cement and arsenic that we use in our study 82‐87 . As a reflection of this, the thermal conductivity of the lead oxide doped CCN5, CCN6, CCN7, and CCN8 PCMs samples were measured higher, as can be seen in the graph.…”

Study on the Influence of Reinforced Particles Spatial Arrangement on the Neutron Shielding Performance of the Composites

“…Moreover, the maximum and the minimum relative neutron fluxes are listed in Table 3 and the statistical error was about 0.1-2.0%. As shown in Figure 8, for thermal neutrons, the neutron absorption cross section of 10 B is much higher than that of 316 stainless steel. Therefore, it can be considered that thermal neutrons will be absorbed in regions with B 4 C distribution, while 'neutron channels' will be formed in regions without B 4 C distribution.…”

“…At the same time, it is worth noting that the influence of B 4 C spatial arrangement on the shielding performance of the composites changes with neutron energies. The absorption cross section of 10 B nuclides to thermal neutron is about three orders of magnitude higher than that of other nuclides in the composites, as shown in Table 2; thus, the different spatial arrangements of 10 B can cause a difference in shielding performance. When neutron energy is 0.0253 eV, the neutron shielding performance of the four kinds of composites varies greatly.…”

“…At the same time, polymers are also used in spent storage casks to shield neutrons because the microscopic cross section of elastic collision between hydrogen element and neutron is large [5,6]. Common matrix materials for neutron shielding include 316 stainless steel and polyethylene (PE) [7][8][9][10] and a B 4 C particle is used as neutron absorption material because of its advantages of high thermal neutron capture cross section, high strength, low density and inactive chemical properties [11]. The fundamental reason is that the inelastic scattering cross sections of heavy elements relative to neutrons are relatively high, such as iron, chromium and nickel in 316 stainless steel, and the elastic scattering cross sections of light elements relative to neutrons are relatively high, such as carbon and hydrogen in PE, and the absorption cross sections of 10 B in B 4 C are extremely high.…”

Smart Lattice Structures with Self-Sensing Functionalities via Hybrid Additive Manufacturing Technology

“…The lattice structure is a kind of cellular material with the regular repeating structure of their unit cell [ 1 ]. Owing to its extraordinary mechanical performances, e.g., specific mechanical strength [ 2 ], ultra-low density [ 3 ], tunable thermal conductivity [ 4 ], and negative Poisson’s ratio [ 5 ], etc., lattice structures have been applied to medical [ 6 , 7 ], energy absorption [ 8 , 9 ], aerospace [ 10 , 11 ], nuclear engineering [ 3 ], flexible and wearable devices [ 12 ]. Traditionally, lattice structures are fabricated via water jet cutting [ 13 ], investment casting [ 14 ], and wire-woven methods [ 15 ], which cause waste of materials, limited design flexibility, and difficulty in manufacturing microstructures.…”