Heat Shield Research Articles

Near‐Infrared Reflectance, Thermal Shielding, and Corrosion Resistance of Neodymium‐Modified Zinc Aluminate Spinel‐Based Zinc Phosphate Coatings

Given the increasing demand for energy‐efficient and durable coatings, particularly in outdoor environments, this study investigates the development of lavender‐shaded neodymium (Nd)‐modified zinc aluminate pigment for thermal energy‐saving applications. The results evidence the potential of incorporating this Nd‐modified ZnAl2O4 pigment in zinc phosphate (ZP) coating to tune the morphology, microstructure, near‐infrared (NIR) reflectance, thermal shielding, and corrosion resistance capability. The study provides a detailed elucidation of the mechanism of pigment particles’ incorporation into ZP coating, revealing enhanced nucleation and crystal size refinement, leading to denser coating with improved NIR reflectance and corrosion resistance, with aesthetic requirements potentially suitable for outdoor environments. Quantitative analysis reveals a maximum NIR reflectance of 93%, thermal shielding capacity with a temperature difference of 15.4 °C, and a more than threefold reduction in corrosion current density. The study underscores the potential of these coatings for energy‐saving applications and outdoor use, highlighting their stability and effectiveness in various environmental conditions.

Preparation and infrared shielding of polyaniline@MWCNTs flexible electrochromic device based on cotton fabric

Electrochromic fabric was formed by interfacial polymerization of polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) on the surface of cotton cloth. The morphology and properties of the composite films were controlled by changing the content of multi-walled carbon nanotubes. The electrochromic properties of the fabric and its application in the field of near-infrared thermal shielding were studied. It is found that the electrochromic fabric with MWCNTs have better electrochemical and color-changing properties. Electrochromic fabrics achieve color changes from light yellow to yellow-green to dark green in the voltage range of -1.0 to 1.2V, and maintain a fast color switching time (2.15s for coloring, 1.89s for bleaching) after 600 cycles. The reflection contrast (ΔR) at 500nm is 23.01%. Moreover, the electrochromic devices are assembled with fabrics. The device has obvious discoloration and good bending stability. In addition, the thermal shielding is realized by using their reflection characteristics in the visual-near-infrared region. The results show that the electrochromic device has a low surface temperature at different environmental condition, and the thermal reduction from the original state to the bleached state is up to 3.8 ° C, indicating the potential application of the device in thermal regulation.

Thermal Shielding Gd3TaO7-Based Thermal Barrier Ceramic with Ultralow NIR Transmittance.

Most thermal barrier coating materials exhibit transparent/semi-transparent properties at higher temperatures, causing the surface heat flow to directly heat the substrate with infrared radiation, which significantly reduces the thermal barrier effectiveness. Herein, composite ceramic materials composed of GdFeO3 diffusely dispersed within the Gd3TaO7 are produced. Specifically, the 0.9Gd3TaO7/0.1GdFeO3 composition demonstrates an ultra-low near-infrared (NIR) transmittance of less than 0.1% across the 400-2500nm range. The introduction of variable-valence behavior and oxygen vacancies contribute to the narrow bandgap of GdFeO3. The incorporated GdFeO3 produces extra multimode vibrations, resulting in the strong infrared emissivity of Gd3TaO7/GdFeO3 composite ceramics. Besides, the refractive index difference between Gd3TaO7 and GdFeO3 can contribute to the potential photons scattering within the composites, severely impeding the infrared radiation penetration. The upward curvature of the thermal conductivity curve of 0.9Gd3TaO7/0.1GdFeO3 at high temperature is significantly suppressed, confirming its excellent IR radiation shielding properties. Moreover, the Gd3TaO7/ GdFeO3 composite ceramic exhibits thermal suitability, with a thermal expansion coefficient (9.47-9.67 × 10-6 K-1 at 1400°C) comparable to YSZ. These combined benefits position the Gd3TaO7/ GdFeO3 composite ceramic system as a promising candidate for the development of infrared radiation shielding and high-emissivity thermal radiation materials.

Polyethylene glycol modified polysiloxane and silver decorated expanded graphite composites with high thermal conductivity, EMI shielding, and leakage-free performance

Phase change thermal interface materials (PCTIMs) have attracted significant attention due to their dual capability in temperature control and thermal buffering. However, the widespread application of PCTIMs in electronic devices is hindered by critical drawbacks such as low thermal conductivity (к), absence of electromagnetic interference shielding effectiveness (EMI SE), poor flexibility, and susceptibility to leakage. In this study, leakage-free PCTIMs were successfully fabricated with ultra-high thermal conductivity (к∥ = 23.4 W m−1 K−1, к⊥ = 8.1 W m−1 K−1), outstanding phase change functionality, exceptional EMI SE (73.2 dB), and excellent flexibility. A polyethylene glycol-modified polydimethylsiloxane (pPDMS) was synthesized through chemical grafting, demonstrating its significant potential as substrates for PCTIMs. Moreover, a designed material called silver nanoparticles-decorated expanded graphite (Ag-EG), was prepared to facilitate multidimensional material collaboration and incorporated into the pPDMS matrix to obtain Ag-EG@pPDMS composites. This integration resulted in a three-dimensional (3D) multi-layer orientation structure that enabled superior thermal conductivity in both in-plane and through-plane directions. To investigate the influence of 3D multi-layer orientation structure on Ag-EG@pPDMS, theoretical analysis was conducted using Effective Medium Theory (EMT) and Foygel thermal conduction models, which were further simulated by finite element analysis confirming substantial enhancement in material properties attributed to the 3D multi-layer orientation structure. Thermal management and electromagnetic interference (EMI) shielding applications were conducted using computers, wireless bluetooth earphones, and other electronic devices, indicating the superior thermal conductivity and EMI shielding of Ag-EG@pPDMS composites.

Fabrication of multifunctional cu-coated melamine foam by electroless chemical deposition technique for thermal management, EMI shielding, and antibacterial applications

Melamine foam (MF) inherently possesses excellent flame-retardant properties due to its ability to release nitrogen upon combustion. Its porous and loose structure also contributes to its high flexibility, breathability, and sound absorption capabilities. Incorporating copper nanoparticles (Cu NPs) significantly enhances the material's electrical conductivity, including its electromagnetic shielding effectiveness, thermal conductivity, and antibacterial properties. This, in turn, greatly broadens the material's potential applications. This research investigated the coating of Cu NPs on three-dimensional MF using an electroless chemical deposition technique to fabricate multifunctional materials. The electromagnetic shielding effectiveness (SET) increased to 85 dB as the Cu NPs content rose from 0 to 0.31 g. Similarly, the electrical conductivity increased from 0.19 to 357 S/m. These results indicate that the Cu-coated MF has high EMI shielding and conductivity properties. The strong adhesion of the Cu NPs to the MF surface created a coating with low infrared emissivity, contributing to the material's excellent thermal insulation properties. With a modest supply voltage of around 4 V, the material exhibited promising electrical conductivity, generating additional warmth of up to 74 °C through efficient joule heating. Furthermore, the Cu-coated MF demonstrated 100 % antibacterial activity, making it a promising candidate for a variety of applications.

Optical, thermal, and radiation shielding characterization of bismuth-modified zinc-lithium-tungsten-borate glass

Abstract This study examines the optical, thermal, and radiation attenuation properties of zinc-tungsten-lithium-borate glass modified with Bi2O3, synthesized using melt-quench techniques. The resulting glass samples display a significant physical property, with density increasing from 3.22 g/cm³ to 4.84 g/cm³ as Bi2O3 concentration increase from 2 to 16 mol%. The optical band gap narrows from 2.9 eV to 2.55 eV, while the refractive index increases from 2.42 to 3.49, indicating a shift in absorption to lower energy levels. Higher Bi2O3 concentrations reduce optical non-linearity while enhancing the linear optical properties of the synthesized glasses. The formation of orthoborate anions suggests that Bi3+ ions in the glasses act as network modifiers, disrupting the borate framework and introducing structural disorder. Additionally, thermal properties, including glass transition temperature (T_g), crystallization temperature (T_c), and melting temperature (T_m), decrease with increasing Bi2O3 concentration. The radiation shielding effectiveness is significantly improved, with the linear attenuation coefficient (LAC) increasing from 0.56 cm⁻¹ to 1.35 cm⁻¹ at 0.284 MeV and from 0.127 cm⁻¹ to 0.186 cm⁻¹ at 2.506 MeV as Bi2O3 content rises from 2 mol% to 16 mol%. For a glass thickness of 1 cm, the radiation protection efficiency reaches approximately 74% for a photon energy of 0.284 MeV in the sample doped with 16 mol% Bi2O3. The glass's remarkable combination of high transparency and effective radiation attenuation, positions it as a promising option for radiation shielding applications.

Practical magneto-optical imaging of the current density of coated conductors within liquid nitrogen.

Magneto-optical imaging (MOI) is widely used for magnetic studies of superconducting materials due to its advantages of full-field, real-time operation and high resolution. However, a traditional MOI system requires vacuum pumping, thermal shielding, and cooling by thermal conducting, thereby making the system very complex and expensive and increasing the time required to complete a set of experiments. In this study, a novel (to our knowledge) and practical approach for MOI within liquid nitrogen (LN) is proposed in which thermal conducting, thermal shielding, and vacuum pumping are no longer necessary. The key technique is realized through a semi-immersed polymethyl methacrylate (PMMA) bar in LN, and its size is optimized to ensure a stable temperature difference and polarized optical visualization within LN. With the improvised method, a defect in a superconducting layer of length approximately 250 µm in the coated conductor (CC) sample was detected. Additionally, the current density reduced by approximately 50% in magnitude compared to its neighbor region, thus demonstrating the effectiveness of the new approach. It is expected that this technique can further enhance the application of MOI as an efficient tool for industrial inspection of superconducting CCs.

Remarkable improvement in radiation shielding efficiency, thermal insulation performance and compressive strength of rigid polyurethane foam composites by synergetic effect of PbO and colemanite fillers

Developing radiation shielding materials is a critical phenomenon for protecting people and the environment with the increment in usage of nuclear technology in today's world. With this sense, PbO/colemanite-filled rigid polyurethane foams were fabricated by one-shut free rise method, and their performances were investigated via the advanced characterization techniques such as ATR-FTIR, SEM-EDS, TGA as well as thermal conductivity, universal mechanical and radiation shielding tests. The characteristic properties of the samples were evaluated in detail depending on the variation in the filler contents. The ATR-FTIR analysis illustrated that RPUF matrices exhibited good compatibility with the fillers by forming the secondary chemical bonds. Furthermore, SEM analysis revealed that the samples with low PbO/colemanite fillers exhibited fairly uniform and regular cellular morphology with anisotropic elliptical apparition thanks to synergetic catalytic effect of the filler particles, whereas, at high content, some local distortions with slightly chaotic appearance were observed accompanied by viewing the little ruptures and bursts in cell face and collapsed in cell plateau borders. TGA measurement indicated that the inclusion of the fillers into RPUF got worse the samples with comparison of neat RPUF due to the reduction in crosslinking density of the foam. Remarkable improvement (about 25 %) was also obtained in thermal insulation performance at the foam composites containing the fillers due to highly augmentation in number of closed cells and presence of more immobile CO2 gas inside the cells. Furthermore, high inclusion of the fillers in RPUF matrix improved compressive strength of the foams by nearly 15 % by enhancing the bending moment and rigidity of RPUF matrices via contributing to the overall stress dispersion. According to linear and mass attenuation coefficients results, the foam composites displayed excellent X-ray radiation shielding performance with increasing of PbO/colemanite content thanks to the density increment and presence of the atoms with high atomic number. Furthermore, at low photon energy levels, better shielding against X-ray radiation was obtained, while vice versa at high energy levels.

Developing computational and experimental models of heat transfer through multi-layered textile structures

Object signature management is a critical and urgent task that helps conceal and restrict the detection of contemporary optoelectronic systems. The design of thermal camouflage textiles and material solutions constitute a significant scientific area, however publications in this area are restricted because of military competitiveness and technological secrecy. Research on thermal camouflage materials has drawn interest both domestically and internationally for a variety of purposes, especially in military applications. Multi-layered Textile Structures (MTS) is a material with several advantages, such as its simple structure, capacity to combine many different materials with many different qualities, and great applicability. The article includes a model of computation and simulation of heat transfer through multi-layer textiles, as well as tests to assess the heat shielding effect and heat radiation energy of some samples of multi-layer textiles made of domestic materials. The initial computational and experimental results constitute an important foundation for further research and application of multi-layered textile structures.

Study on the mechanical properties and gamma/neutron radiation shielding performance of SnBi/B4C composite materials

The development of multifunctional shielding materials has become a hot research topic with the increasing requirements for radiation protection materials in terms of performance, weight and non-toxicity. In this study, non-toxic SnBi/B4C composites with different B4C contents (0, 3, 6, 9, 12 and 15 wt%) were successfully prepared by powder metallurgy, and their mass attenuation coefficients, half-value layers, mean free paths, effective atomic numbers, and 0.025 eV thermal neutron shielding performance. The results show that B4C plays a key role in regulating the mechanical properties and thermal neutron shielding properties of SnBi/B4C composites. When the B4C content was 9 wt% (S3), the integrated mechanical properties of the composites were optimal, and the yield strength, tensile strength, and microhardness were enhanced by 31 %, 32 %, and 129 %, respectively, compared with those of the samples without B4C. The radiation shielding effect is remarkable, the gamma-ray shielding performance in the energy range of 0.03–0.08 MeV is better than that of Pb. Meanwhile, the S3 sample with only 3 mm thickness can shield 99.7 % of thermal neutrons, while the shielding rate of the S0 sample without B4C is only 5.2 %. Comprehensive analyses show that the SnBi/B4C composites are superior in terms of environmental protection, mechanical properties, gamma-ray and thermal neutron shielding, with lighter weight and safer use. This finding provides a theoretical basis for the selection of efficient, non-toxic and diverse radiation shielding materials for medical and other special environments.

Micromorphology tunable Eu2O3 submicron spheres reinforced boron-containing HDPE composites for neutron and gamma-ray complex radiation shielding

In this research, a series of Eu2O3/B4C/HDPE composites containing micromorphology tunable Eu2O3 submicron spheres as fillers are prepared for shielding neutron and gamma ray. The influence of microstructure of Eu2O3 fillers on thermal stability, mechanical, and radiation shielding properties of composites are studied in detail. The growth process of Eu2O3 precursor (Eu(OH)CO3) follows the LaMer and Ostwald ripening mechanism. The FESEM reveal that the microstructure of synthesized Eu2O3 is submicron sphere and the particle size decreases with addition of urea content in the reactant solution. HRTEM and SEAD images reveal that the overall crystal morphology of the Eu2O3 fillers is polycrystalline. BET analyses reveal that the hysteresis loops of nitrogen adsorption-desorption isotherms changes from Type H1 to H3 after Eu2O3 fillers are ball-milled, which is attributed to the suppression of nanoparticle agglomeration by ball milling. The FESEM images and EDS mapping of the fracture surfaces of the composites reveal that Eu2O3 fillers are evenly distributed in the HDPE matrix. It is revealed that under the condition that the agglomeration of the nanoparticles is effectively suppressed, the higher BET-specific surface area and smaller size of Eu2O3 fillers are conducive to the various properties of the composites. The superior composite containing Eu2O3 (R = 1:30)/B4C/HDPE has a 99.1 % neutron shielding rate with 15 cm thickness under a 252Cf neutron source and a 73.1 % gamma shielding rate with 15 cm thickness under a 137Cs gamma source.

Interfacial metallization in segregated structured PEEK composite for enhanced thermal conductivity and electromagnetic interference shielding

The increasing integration of electronic devices has created an urgent demand for multi-functional composites with efficient thermal management and electromagnetic interference (EMI) shielding. In this study, a three-dimensional (3D) continuous metal–carbon hybrid thermally/electrically conductive network structure is fabricated by in-situ nickel plating of core–shell structured polyetheretherketone (PEEK) hybrid particles. The hybrid particles realize phonon and electron dual heat-transfer pathways and reduce the interfacial thermal resistance by using metallic Ni nanoparticles to bridge the gap. Furthermore, the interfacial metallization and segregated structure significantly enrich the multiple electromagnetic wave reflection and attenuation mechanisms. The PEEK composites with metallized-segregated structure and filler content of 28.26 vol% exhibit an excellent through-plane thermal conductivity of 6.52 W m−1·K−1 and an efficient EMI shielding of 91 dB, thus demonstrating their significant potential as multi-functional thermal management materials. The heat-transfer and EMI shielding process of the composites can be visualised using the finite element model, which further proves the effectiveness of the segregated structure and metallization. This simple and efficient strategy is expected to facilitate the manufacture of multi-functional thermal management composites with high thermal conductivity and excellent EMI shielding.

Development and Verification of a Multi-Physics Transport Code of Molten Salt Reactor Fission Products

The transport of fission products in molten salt reactors has attracted much attention. However, few codes can completely describe the transport characteristic, though the migration of fission products in the molten salt reactor is essential to estimate the source term, decay heat, and radiation shielding. This study built a program named ThorFPMC (Thorium Fission Products Migration Code) that can handle the multi-physics transport characteristic based on the flow burnup code ThorMODEc (Thorium MOlten Salt Reactor Specific DEpletion Code). A problem-related depletion chain compression method was applied to decrease the order of the solve matrix. The matrix exponential and splitting methods were applied to solve the steady state and transient calculation, respectively. Error analysis showed that for a specific problem, the simplified depletion chain matrix index method could solve the fission products migration equation with an arbitrary time-step with high speed (s) and high precision (10−4); the splitting method could reach a precision of 10−2 level for the full fuel depletion chain, multi-nodes, and transient problems. Compared to the Strang splitting method, the perturbation splitting method has higher precision and less time consumption. In summary, the developed programmer could describe the migration effect of fission products in molten salt reactors, which provides a significant tool for the design of molten salt reactors.

Distect: automatic sample-position tracking for X-ray experiments using computer vision algorithms.

Soft X-ray spectroscopy is an important technique for measuring the fundamental properties of materials. However, for measurements of samples in the sub-millimetre range, many experimental setups show limitations. Position drifts on the order of hundreds of micrometres during thermal stabilization of the system can last for hours of expensive beam time. To compensate for drifts, sample tracking and feedback systems must be used. However, in complex sample environments where sample access is very limited, many existing solutions cannot be applied. In this work, we apply a robust computer vision algorithm to automatically track and readjust the sample position in the dozens of micrometres range. Our approach is applied in a complex sample environment, where the sample is in an ultra-high vacuum chamber, surrounded by cooled thermal shields to reach sample temperatures down to 2.5 K and in the center ofa superconducting split coil. Our implementation allows sample-position tracking and adjustment in the vertical direction since this is the dimension where drifts occur during sample temperature change in our setup. The approach can be easily extended to 2D. The algorithm enables a factor of ten improvement in the overlap of a series of X-ray absorption spectra in a sample with a vertical size down to 70 µm. This solution can be used in a variety of experimental stations, where optical access is available and sample access by other means is reduced.

Comprehensive analysis of thermal performance and low-grade energy charging efficiency of pipe-embedded building envelopes enhanced with single-level tree-shaped fin structures

Pipe-embedded walls (CnPWs) are structural and energy composite building components that can resist external disturbances by forming stealth thermal shielding layers. To tackle the mismatch between the heat charging rate and heat diffusion rate during energy charging processes, as well as the unsatisfactory robustness of stealth thermal shielding layers, the single-level tree-shaped metal finnd pipe-embedded walls (TfPWs) are proposed. To verify the effectiveness of TfPWs and obtain dynamic performances, a simulation study is conducted on 8 risk variables in 4 pairs through the validated numerical model. Results showed that the improved design was effective in obtaining more robust thermal shielding layers in auxiliary energy supply mode, the effect gained prominence as both the injection temperature and pipe spacing were augmented. In room heat load reduction mode, favorable benefits arise when pipe spacing exceeds 400 mm. The maximum increase rate of total injected energy under different reduction ratios of external insulation layer was 11.83%–31.91 %, while the maximum extra total heat loss was 5.33 %. Secondly, the trunk fins and branch fins played different roles in minimizing the excessive heat accumulation surrounding pipes, and the vertical and horizontal sizes of heat accumulation region mainly increased with the increase in trunk fin size and branch fin size respectively. Meanwhile, the utilization efficiency of fin material was higher when trunk fin size was smaller, and parameter combinations with trunk fin size of 0.2b and branch fin size of 0.4a/0.6a could achieve a better balance between material input and performance increase. Thirdly, the improvement effect of single left branch fin schemes was close to that of double branch fin schemes and significantly better than that of single right branch fin schemes. It was recommended to use single left branch fin schemes with an inclination angle of 60°. Finally, even if the reduction ratio of external insulation layer in different cities increased to 80 %, the inside surface temperature of TfPWs was still greater than room air. Taking CnPWs with standard external insulation layer as references, the TfPWs applied in Harbin, Beijing, and Shanghai could achieve similar or better results even when the reduction ratio of external insulation layer increased to 60 %, while TfPWs applied in Guangzhou could exhibit better performance even when the reduction ratio of external insulation layer increases to 80 %.

Microfluidic Exploitation of Liquid Crystal Properties of Boron Nitride Nanotubes and Enhancing Neutron Shielding with Aligned Structure

Boron nitride nanotubes (BNNTs) are cylindrical nanostructures characterized by alternating boron and nitrogen atoms. Unlike carbon nanotubes (CNT), BNNTs are electrically insulating and exhibit high thermal stability and neutron shielding capabilities. Their unique tubular structure enables the formation of 1D arrays, which can achieve a nematic liquid crystal phase, ideal for fabricating high‐density structures. However, the widespread application of BNNTs has been hindered by challenges in purifying and dispersing high‐purity BNNTs. This study aims to exploit the liquid crystal properties of BNNTs by generating high‐purity BNNT dispersions through a series of dispersion and purification processes. Furthermore, this study utilizes microfluidics technology to encapsulate the BNNT dispersions. Using this approach, the transition of liquid crystal phases in relation to BNNT concentration is efficiently examined. This process results in the production of high‐density BNNT films characterized by pronounced anisotropy, which in turn provides significant thermal neutron shielding effects.

Nanosilica-Reinforced Poly(dimethylsiloxane) Stretchable Transparent Electrodes and Multifunctional Applications.

Soft and stretchable transparent electrodes still face many challenges, requiring a balance between stretchability, conductivity, transparency, and stability. In this paper, poly(dimethylsiloxane) (PDMS) elastomer is selected, and amphoteric nonionic surfactants (Triton X-100) are introduced to improve the interfacial bonding between nanosilica (SiO2) and the elastic matrix. At the same time, a fluorosilane-modified glass template is used to induce nanosilica enrichment on the membrane surface. Based on the dual effects of nanoenhancement and surface regulation, a PDMS transparent nanocomposite membrane with good stretchability, surface hydrophilicity, and easy in situ polymerization of polydopamine can be obtained. Silver nanowires (AgNWs) and poly(3,4-ethylenedioxythiophene)/polystyrenesulfonate (PEDOT:PSS) conductive polymers can be assembled layer by layer on the surface of the nanocomposite membrane by simple spin coating and heat treatment. The transmittance of the soft and stretchable composite membrane can reach 63% in the visible light range, and the strength and elongation at break increase to 2.30 MPa and 150%, respectively. The sheet resistance of the stretchable transparent dry electrode is as low as about 6 Ω/sq. After being placed in the air for 3 months, the resistance increment is less than 5%, showing good environmental stability. The stretchable transparent electrode prepared based on the material-structure-preparation integrated method has brilliant application potential in wearable thermal management, electrochromism, strain sensing, and electromagnetic shielding.

Porous TiO2 microspheres containing MgO nanoparticles/epoxy composite with superior thermal conductivity, EMI shielding, and electrical insulation

With the continuous advancement of electronic devices, the amounts of heat as well as electromagnetic (EM) waves generated have increased. Materials with high thermal conductivity and excellent EM interference shielding effectiveness (EMI SE) can be utilized to address this issue. In this work, we synthesized hollow anatase TiO2 microspheres. Through a reaction, MgO nanoparticles were incorporated into the interior of TiO2 microspheres. (H-TiO2/MgO). The heterostructure of the fillers contributed to performance enhancement. TiO2 and MgO particles formed a dual thermal-conduction pathway. H-TiO2/MgO effectively weakened the energy of EM waves upon contact. Additionally, TiO2, MgO, and epoxy all exhibited hydrophilicity. Consequently, the interfacial compatibility between H-TiO2/MgO and epoxy was excellent. They formed strong interfacial interactions by hydrogen bonding. Because of the excellent electrical insulation properties of H-TiO2 and MgO, the composites exhibited superior insulation performance (over 1010 Ω·cm). Our H-TiO2/MgO/Epoxy composites exhibited a maximum thermal conductivity of 7.52 W/m·K, an EMI SE of 64.92 dB, and a tensile strength of 79.10 MPa. Our composites are expected to effectively manage heat and EM waves generated by electronic devices.

Investigation of mechanical and radiation shielding properties of Sm–Sm2O3 reinforced Al–B4C composite

In this study, Al–20%B4C-x%(Sm, Sm2O3) (x = 1, 3, and 5) composites were prepared using mechanical alloying to investigate their neutron shielding and mechanical properties. After pelletizing and sintering the prepared powder composites, their microstructures were characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Hardness, density, and corrosion tests were performed on the composites. Thermal and fast neutron shielding properties were calculated using the MCNP simulation code. Experimental measurements of neutron shielding were carried out using an Am–Be neutron source. Experimental results showed that 5% Sm-reinforced composites exhibited better neutron shielding than Sm2O3-reinforced composites at all doping ratios. Simulation calculations indicated that the highest thermal neutron shielding rate was observed in Sm-reinforced composites, while the highest fast neutron shielding rate was observed in 5% Sm2O3-reinforced composites. This research provides important data for researchers interested in developing thermal and fast neutron shielding materials.

Multidisciplinary space shield origami composite: Incorporating cosmic radiation shielding, space debris impact protection, solar radiative heat shielding, and atomic oxygen erosion resistance

Origami composites have been extensively utilized in space structures with constrained payload volumes due to their capability to efficiently transform compact structures into larger surface area or volume configurations. The proposed origami composite incorporates hydrogen-rich benzoxazine polymers known for their high radiation shielding capability and ultra-high-molecular-weight polyethylene fibers known for their high ballistic performance, radiation shielding capability, and flexibility. The proposed origami composite and manufacturing method can enhance bonding strength by achieving precise origami shapes and utilizing the same matrix for both flexible and rigid components. Membrane sheets are manufactured at a low curing temperature to provide flexibility, while rigid facets are separately manufactured at a high curing temperature to increase rigidity. The integration of a polyimide protection layer significantly enhances space environment resistance and reduces mass loss due to atomic oxygen erosion. Despite a slight decrease in ballistic performance after exposure to space conditions, the proposed origami composite maintains superior ballistic performance compared to conventional space materials and conventional origami composites. Compared to existing origami composites or conventional space materials, the proposed origami composite exhibited superior radiation shielding performance. The laminated structure of the proposed origami composite can offer some solar radiation shielding capability. The proposed origami composite offers a multifunctional origami solution as a membrane-space shield material, fulfilling requirements for high ballistic performance, cosmic radiation shielding, solar radiative heat shielding, and space environmental resistance.