Flexible Shielding Research Articles

Recycling efficiency optimization of tungsten-filled Vinyl-Methyl-Silicone-based flexible gamma ray shielding materials

Tungsten has been widely used for gamma-ray and X-ray radiation shielding, which is one of the main elements of shielding materials. Compared with traditional lead-containing shielding materials, tungsten-containing shielding materials have several advantages, such as good chemical stability, a high melting point and relative environmental friendliness. Considering the recycling of resources, the optimization of pyrolysis temperature and pyrolysis duration of tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials needs to be studied. In this paper, these tungsten-filled Vinyl-Methyl-Silicone-based flexible shielding materials were initially recycled using pyrolysis. Subsequently, the crystal structures, surface chemical states and the tungsten concentration after pyrolysis in an argon atmosphere were characterized. In order to increase the tungsten recycling rate, the pyrolyzed samples were further recycled using the ultrasonic cleaning method. Furthermore, the influence of ultrasonic cleaning on tungsten recycling rate and surface morphologies was characterized and analyzed. It is found that the tungsten recycling rate of tungsten-filled Vinyl-Methyl-Silicone based flexible gamma/X-ray shielding material was around 69.9 wt%-81.6 wt% by using the pyrolysis method, while the recycling rate of tungsten can exceed 90.0 wt% by ultrasonic cleaning after pyrolysis.

Evaluation of X-ray radiation shielding performance of Bi2O3 and BaTiO3 embedded in PVP and PEG polymer nanocomposite

This study addressed the limitations of lead-based radiation shields by developing lead-free, non-toxic, lightweight, and flexible shielding materials with high attenuation efficiency. To achieve this, single and triple layers of Bi2O3-BaTiO3/PVP-PEG nanocomposite films were synthesized. Polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) polymers (2:1 ratio) were used as the polymeric matrix in which fillers of Bi2O3 and BaTiO3 nanoparticles (NPs) with particle sizes ranging from 90 to 210 nm and <100 nm, respectively, were embedded. Four single-layer samples with 20%, 30%, 40%, and 50% NP concentrations were prepared; the samples were 1.05, 1.09, 1.27, and 1.42 mm thick, respectively. Two samples of triple-layered films were prepared with 30% and 50% NPs, measuring 3.78 and 4.23 mm in thickness, respectively. The attenuation efficiency of these films was investigated using X-ray tube voltages from 10 to 120 kVp. Further, the flexibility of the synthesized films was tested by manual handling. All single- and triple-layer nanocomposites exhibited effective radiation attenuation and desirable flexibility. Specifically, at the lowest tube voltage, all samples exhibited 100% attenuation, while at the highest tube voltage, the attenuation ranged from 27% to 84%, depending on the NP concentration and number of layers of the sample. The highest attenuation ratio, observed in the 50% triple-layer sample, reached 100% up to approximately 60 kVp and 84% at 120 kVp. Consequently, the most optimal film synthesized in this study had a triple-layer configuration with 50% Bi2O3-BaTiO3 NPs embedded in a PVP-PEG polymer with an average attenuation of 95.5% for all tube voltages (10–120 kVp). Therefore, this shielding is suitable for various diagnostic applications, such as mammography, dental X-rays, computerized tomography, and fluoroscopy. Highlights Single- and triple-layered nanocomposite Bi2O3-BaTiO3/PVP-PEG films were synthesized The attenuation efficiency of the films against X-rays was investigated A triple-layer configuration with 50% Bi2O3-BaTiO3/PVP-PEG was suitable for various diagnostic applications

Electromagnetic Interference Shielding Properties of Highly Flexible Poly(styrene-co-butyl acrylate)/PEDOT:PSS Films Fabricated by Latex Technology.

As the use of stretchable electronic devices increases, the importance of flexible electromagnetic interference (EMI) shielding films is emerging. In this study, a highly flexible shielding film was fabricated using poly(styrene-co-butyl acrylate) (p(St-co-BA)) latex as a matrix and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a conductive filler, and then the mechanical properties and EMI shielding performance of the film were examined. Styrene and butyl acrylate were copolymerized to lower the high glass transition temperature and increase the ductility of brittle polystyrene. The latex blending technique was used to produce a shielding film in which the aqueous filler dispersion was uniformly dispersed in the emulsion polymerized resin. To determine the phase change in the copolymer matrix with temperature, the storage modulus was measured, and a time-temperature superposition master curve was constructed. The drying temperature of water-based copolymer resin suitable for film fabrication was set based on this curve. The glass transition temperature and flexibility of the blends were determined by evaluating the thermomechanical analysis and tensile tests. The EMI shielding effectiveness (SE) of the films was analyzed at frequencies from 50 MHz to 1.5 GHz, covering the VHF and UHF ranges. As the filler content increased, the SE of the blend film increased, but the elongation increased until a certain content and then decreased. The optimal content of PEDOT:PSS that satisfied both the ductility and shielding performance of the film was found to be 10 wt%. In this case, the elongation at break reached 300%, and the SE of a 1.6 mm thick film was about 35 dB. The film developed in this study can be used as an EMI shielding material that requires high flexibility.

High performance fluoroelastomer composites filled with graphite and/or bismuth oxide for applications in gamma‐ray shielding

AbstractFluoroelastomer‐based composites with nano‐sized bismuth oxide (B) and/or graphite (G) as fillers were prepared and characterized using FKM type 1 fluoroelastomer as a matrix. The effects of these fillers used singly or in combination on the crosslinking process, mechanical, thermal, dynamic mechanical, electrical, optical, and high‐energy radiation attenuation properties of FKM were investigated. The results showed that graphite significantly increased the moduli E50 (MPa) of FKM/G and FKM/GB composites by 1026% and 1459%, respectively, compared to FKM. On the other hand, bismuth(III) oxide did not affect the stiffness or elongation at break of FKM significantly. Graphite also imparted electrical conductivity to FKM (10−6 Scm−1), which was reduced by bismuth oxide to 10−12 Scm−1. Furthermore, the linear attenuation coefficients (μ), half‐value layer (HVL), and tenth‐value layer (THV) of pure FKM and FKM composites were evaluated using a 137Cs (662 keV) source, revealing that FKM/B and FKM/GB composites show 47.4% and 35.8% higher μ values, respectively, than FKM. Taking into consideration that the attenuation coefficient of FKM is 10 times higher than conventional elastomers such as natural rubber, these results indicate that thin flexible shielding against high electromagnetic radiation can be achieved to protect different sensitive equipment such as electronic devices used in nuclear power plants, gamma radiation facilities, telescopes, and artificial satellites.Highlights A fluoroelastomer‐based composite containing 40 phr of bismuth(III) oxide nanopowder presents a gamma attenuation coefficient 47.4% higher than that of the polymer matrix. A fluoroelastomer‐based composite containing bismuth(III) presents a band gap of 2.40 eV. Bismuth(III) oxide nanopowder hinders the electrical conductivity imparted by a conducting filler contained in the fluoroelastomer‐based composite. Fluoroelastomer‐based composites containing graphite or bismuth(III) oxide present enhanced mechanical and thermal properties.

Flexible Axial Shielding Strategy for Improving Ethylene (Co)polymerization with 8-Cycloalkylnaphthyl α-Diimine Catalysts.

8-aryl or alkyl-naphthyl substituents are widely used as an effective axial shielding strategy for the suppression of chain transfer in late-transition metal-catalyzed ethylene (co)polymerization to yield high molecular weight polyethylene and copolymers. In this study, two 8-cycloalkylnaphthyl acenaphthene-based α-diimine ligands and the corresponding four nickel and palladium complexes were designed and synthesized to explore the effect of axial flexible shielding on ethylene (co)polymerization. In ethylene polymerization, the nickel complexes displayed high activities (up to 1.99 × 106 g mol-1 h-1) and generated lightly branched (34-54/1000 C) polyethylenes with high molecular weights (up to Mn = 1075 kg/mol), whereas the corresponding palladium complexes exhibited moderate activities (level of 104 g mol-1 h-1), producing highly branched (111-125/1000 C) polyethylenes with high molecular weights (up to Mn = 37.6 kg/mol). Highly branched (110-123/1000 C) E-MA copolymers with moderate insertion ratios (1.97-5.56 mol %) were produced by these palladium complexes in ethylene/methyl acrylate (MA) copolymerization. In addition, the size of the 8-cycloalkyl ring in these α-diimine catalysts strongly influences the ethylene (co)polymerization. Compared to cyclopentyl groups, cyclohexyl groups are more effective in suppressing chain transfer reactions in the polymerization of ethylene and the copolymerization of ethylene and MA, leading to higher molecular weight polyethylene and E-MA copolymers. Most interestingly, compared to the reported rigid planar 8-arylnaphthyl catalysts, the flexible 8-cyclohexylnaphthyl catalysts exhibited higher activity and produced higher molecular weight polyethylene in ethylene polymerization. Moreover, in nickel-catalyzed ethylene polymerization, the cyclohexyl catalyst produced significantly reduced branched polyethylene, while in palladium-catalyzed ethylene (co)polymerization, the cyclohexyl catalyst produced more highly branched polyethylene and copolymers. In contrast to the previously reported flexible 8-butylnaphthyl nickel catalysts, the 8-cycloalkylnaphthyl catalysts reported in this work yielded polyethylene with narrow unimodal molecular weight distributions.

High-orientation, defect-rich and porous graphene films for excellent electromagnetic shielding and thermal management

With the rapid development of portable electronics, the demand for flexible shielding and thermal management materials is increasing steadily. Herein, we reported a scalable flexible graphene film preapred following hydrogen iodide chemical reducing and graphitization thermal reducing. Benifitting from the coordinated reduction, the fabricated graphene film is equipped with varous characteristics of high orientation, rich defect and three-dimensional porosity. Then the graphene film deliver outstanding mechanical property and electrical conductivity (1.2 × 105 S m−1). Moreover, superior electromagnetic interference (EMI) and thermal conductivity are realized compared with the simplex thermal reduction. The EMI effectiveness can reach a high value of 70 dB when the thickness is only 35 μm, and the specific EMI effectiveness is 380 dB/g cm−3. And the relationship between the effectiveness and structure parameters (thickness and density) is uncovered. The thermal conductivity could be up to 864 W m−1 K−1. This research may not only provide a new avenue to the development of flexible shielding and thermal management materials, but also promote the application of graphene.

Radiation synthesis of boronic acid modified graphene oxide for enhance the neutron shielding property of silicone rubber

In this study, poly(3-acrylaminophenylboronic acid) modified graphene oxide (GO-PAAPBA) has been prepared by polymerization of 3-acrylaminophenylboronic acid (AAPBA) on the surface of GO. The –O· free radical was formed by γ-ray radiation, which initiated the polymerization of AAPBA. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Raman spectroscopy were employed to characterize the structure of GO-PAAPBA. The grafting density of poly(3-acrylaminophenylboronic acid) is increased with increasing of the absorbed dose. The GO-PAAPBA was added into vinyl-terminated polydimethylsiloxane (Vi-PDMS) to prepare room temperature cured silicon rubber composites (SR/GO-PAAPBA). The GO-PAAPBA exhibits better dispersion performance than pure GO, which is contribute to improve thermal conductivity and mechanical properties. Significantly, with grafting density of PAAPBA increasing, the comprehensive performances of SR/GO-PAAPBA are more remarkable. SR/GO-PAAPBA-1.88 with outstanding thermal and mechanical abilities exhibits beat neutron shielding property. The neutron transmission of SR/GO-PAAPBA-1.88 is 10% lower than that of SR. The SR nanocomposite with efficient thermal conductivity and neutron shielding ability has a promising prospect to be applied as advanced flexible shielding material.

Study on Performance of New Flexible Shielding Materials and First Demonstration Application in Chinese Pressurized Water Reactor Nuclear Power Plant

Abstract Excessive gamma rays will be emitted when a nuclear power plant is under overhaul, leading to a certain number of hotspots. To meet the shielding requirements of these hotspots, a new type of flexible shielding material with a “sandwich structure” has been developed. The new flexible shielding materials consist of two parts: one is silicone rubber with excellent physical and chemical properties by adding reasonable multicomponent additives as a matrix, and the other is lead powder as a shielding body. This kind of material, with lead powder dispersed uniformly in silicone rubber, was prepared through a mixing process. Based on this, the article has carried on the discussion with the performance of the functional layer of the new flexible shielding materials. The problem of the process stability of ultrafine powder distributed uniformly in a matrix with various densities among different regions has been solved as well. Furthermore, this kind of material has been adopted at the Chinese pressurized water reactor nuclear power plant as the first demonstration project. The site shielding effect has been recognized by the World Association of Nuclear Operators. As a result of this research, it is possible that the design of a radiation shield for a short or long time can be made quickly when a nuclear power plant is running or being overhauled. Meanwhile, this study is of great significance for the popularization and application of shielding materials.

CNT cluster arrays grown on carbon fiber for excellent green EMI shielding and microwave absorbing

Carbon fiber (CF) is a flexible shielding material with excellent electrical conductivity, thermal stability and mechanical properties, which is crucial to solve electromagnetic pollution problems. However, its application in green electromagnetic interference (EMI) shielding is hampered due to high secondary reflection. Herein, we proposed a method to selectively grow CNT cluster arrays on the CF surface for tunable green EMI shielding and microwave absorbing. The density of CNT cluster arrays can be manipulated by controlling of CF surface functional groups in the preparation route of metal-organic framework derived Co-doped CNTs. The CF/CNTs cluster array composites exhibit excellent electromagnetic wave absorbing performance, with an effective absorption bandwidth of 4.4 GHz with a matching thickness of 1.38 mm, which can be extended to full frequency band from 2 to 18 GHz through metastructure design. The green EM shielding index is greater than 12 in the whole frequency range from 2 to 18 GHz, with the maximum value up to 351. The strategy developed here provides a valuable guide for the preparation of electromagnetic functional materials with multilevel hierarchical structure.

A comparative study between pure bismuth/tungsten and the bismuth tungsten oxide for flexible shielding of gamma/X rays

Thermoplastic vulcanizate based flexible W/Bi and bismuth tungsten oxide composites with different doping ratios from 20% to 100% are successfully fabricated. The ray attenuation abilities of the composites are determined at X-ray tube voltages of 80 KVp–120 KVp, and at gamma rays of 59 keV, 122 keV, 343 keV and 960 keV. The surface morphology and elements mapping of W/Bi and bismuth tungsten oxide particles within the polymer have confirmed a more uniform dispersion of bismuth tungsten oxide than W/Bi. Shielding parameters such as transmittance T, mass/linear attenuation coefficients μm and μ, as well as lead equivalent δPb are investigated experimentally and numerically by Monte Carlo code NECP-MCX as well as XCOM program. The transmittance of γ ray decreases exponentially with the areal density of the functional particles, and the best shielding of X-ray goes to 100 KVp tube voltage, followed by 80 KVp and 120 KVp. A comparison of the two series of composites are made that W/Bi always has advantages over bismuth tungsten oxide in attenuation coefficients and lead equivalent, because the extra containing oxygen atoms in bismuth tungsten oxide crystal actually provide very weak additional shielding. Test of mechanical property also reflects the advantage of using pure W/Bi over bismuth tungsten oxide in flexibility. As substitutes for Pb containing materials, these two types of composites could be of potential use in medical diagnosis, interventional surgery, or biological radiation protection, etc.

Designer Fe3O4@Ag Core–Shell Porous Nanospheres for Enhanced Electromagnetic Interference Shielding of Polymer Nanocomposites

Electromagnetic (EM) pollution is a pressing concern owing to the increasing usage of electronic gadgets. To this end, lightweight and flexible shields are in huge demand to comply with modern electronics, Herein, designer core–shell porous nanospheres (PNSs) are synthesized, and along with multiwalled carbon nanotubes (MWCNTs), their composites are developed in ethylene‐vinyl acetate (EVA) with excellent EM interference (EMI) shielding ability. The Fe3O4 PNSs synthesized through controlled solvothermal synthesis are systematically evaluated to elucidate the formation of PNSs to attain porous core–shell morphology. The as‐prepared Fe3O4 PNSs are coated with Ag by electroless deposition. The developed polymer nanocomposite is flexible and lightweight that effectively attenuates the incoming EM radiation with measured shielding effectiveness (SE) up to 29 dB. This work presents novel insights into the evolution of designer PNSs and presents lightweight polymer composites containing the designer PNSs with excellent radiation shielding activity.

Radiation shielding design and development of Bi/Ta/PU lead-free flexible textile composites

Aiming at the difficulty of designing flexible shielding materials for lightweight and complex structures, the radiation shielding simulation model of coated fabric was established by SuperMC nuclear simulation software system and the γ-ray shielding performance of the material was predicted. Pb and Ta doped Bi/PU coated fabric composites were prepared by coating process. SEM, EDS, γ-ray shielding performance, mechanical properties, and wear resistance were tested. The results show that the simulated values of shielding performance are in good agreement with the measured values, the maximum deviation of the predicted value is 2.94% and the minimum is 0.25%. Doping Pb and Ta can increase the probability of the photoelectric effect and improve the γ-ray shielding performance of the material. When the doping amount of Ta is 5wt%, the shielding rate (simulation value) of Bi/Ta/PU coated fabric composites to 59.5 keV, 122 keV, and 184 keV γ-rays reaches 29.80%, 20.35%, and 8.09%, respectively, which is 3.13%, 2.32%, and 0.95% higher than that without doping. However, Ta is more environmentally safe and can replace Pb as a shielding additive. Doping auxiliary functional particles will improve the shielding performance but will reduce the material’s wear resistance and mechanical properties. After doping 5%Ta, the wear resistance index decreased by 6.81, and the tensile strength decreased by 4.5 MPa. The influence mechanism of process parameters on shielding performance is further revealed by visual analysis, which provides a new reference for the design of lead-free flexible shielding materials.

Development of ultra-thin radiation-shielding paper through nanofiber modeling of morpho butterfly wing structure

In medical institutions, radiation shielding is an effective strategy to protect medical personnel and patients from exposure. Reducing the weight of the shield worn by medical personnel in the radiation generating area plays a key role in improving their productivity and mobility. In this study, a new lightweight radiation shield was developed by electrospinning a polymer-tungsten composite material to produce nanofibers with a multi-layered thin-film structure similar to that of a morpho butterfly wing. The fabricated shield was in the form of 0.1 mm thick flexible shielding paper. The multi-layer structure of the thin shielding paper was obtained through nanofiber pattern formation via electrospinning a dispersion of tungsten particles. At 0.1 mm thickness, the paper’s shielding rate was 64.88% at 60 keV. Furthermore, at 0.3 mm thick and arranged in a laminated structure, the shielding rate was 90.10% and the lead equivalent was 0.296 mmPb. When used as an apron material, the weight can be reduced by 45% compared to existing lead products. In addition, the material is highly processable and can be used to manufacture various flexible products, such as hats, gloves, underwear, and scarves used in medical institutions.

Prediction of γ-ray shielding performance and study of Bi/PU coated fabric

The radiation shielding simulation model of coated fabric (flexible composite) was established for the first time by SuperMC nuclear simulation software to help solve the problems of small volume, complex structure, and difficult design of flexible shielding materials, and the γ-ray shielding performance was calculated. Bismuth/polyurethane coated fabric was prepared by a coating method, and its scanning electron microscope, γ-ray shielding performance and mechanical properties were tested. The results show that the simulation accuracy was improved due to the one-to-one correspondence between the structural parameters and performance parameters of the simulation model and the actual samples. The simulation value was in good agreement with the measured value. The shielding performance and mechanical properties of fabric composites were improved after coating. Increasing the content of bismuth and coating thickness can improve the shielding performance of the coated fabric. However, when the content of bismuth was too large, or the coating was too thick, the mechanical properties were relatively decreased. The deposition of ray energy in the material was analyzed by the visual analysis method, and the influence mechanism of process parameters on shielding performance was further revealed, which provided a new theoretical reference for the design of flexible shielding materials. A shielding material design and performance prediction method based on SuperMC is proposed, which can be used for personalized customization design and performance prediction and evaluation before use. It has practical guiding significance for producing and manufacturing flexible fabric shielding materials for protective clothing and equipment.

Gd3+ ionic nano-aggregate clusters enable metallopolymers redox electrolytes as high-performance flexible radiation shielding

In this work, Gd3+ ionic nano-aggregate clusters were introduced into metallo-polyelectrolytes to balance the conflicts between high mechanical robustness and X-ray attenuation of flexible shielding materials. The segmented polyurethanes (PUs) containing main-chain bisferrocene and pendant sulfonates in hard segments is applied as a macromolecular template for the subsequent self-assembly with Gd3+. Rare earths aggregate into dynamic clusters about 2.2 nm, which is beneficial to improve the radiation attenuation ability and mechanical properties of materials. The hierarchical noncovalent interactions (ionic interactions, coordination interactions, hydrogen bonds, and ferrocene-metal interactions, etc.) in the aggregate PUs enable the co-existence of high mechanical strength, large stretchability, and fast radiation dissipation. As a result, this Gd3+ hybrid bisferrocene-based PU demonstrates extremely high tensile properties (breaking stress = 27.8 ± 0.2 MPa, breaking strain = 576 ± 7%) as well as super atomic shielding efficiency (14.39 cm2 g−1) at 65 keV.

Photon, charged particles, and neutron shielding properties of natural rubber/ SnO2 composites

The flexible shielding material based on natural rubber (NR) composites has been developed for radiation shielding materials. The natural rubber (NR) was prepared by incorporating Tin oxide (SnO2) with various loading levels. The addition content of SnO2 to natural rubber improved modulus at 100% elongation, hardness and specific gravity of natural rubber. while the tensile strength and elongation at break were reduced. The WinXCom program was used to calculate theoretical gamma ray shielding parameters. While, the Compton scattering technique was used to measure experimental values in the energy range of 0.223 MeV–0.662 MeV. The mass stopping power (MSP) and projected range (PR) have been simulated by SRIM coding for the proton and alpha particles. Moreover, the fast neutron shielding removal (FNSR) were calculated by Phy-X program. From the results, it was found that adding the SnO2 in the NR structure affected to increase of the photon, and charged particles, while the neutron shielding properties values decreased from adding the SnO2. These results reflect that the NR/SnO2 composites are suitable to apply as flexible radiation shielding materials.

Preparation and assessment of nanocomposites based on natural rubber latex reinforced with multiwall carbon nanotubes for Gamma rays shielding applications

Reinforcement of the flexible shielding properties of natural rubber (NRL) was achieved through various content Multi-walled carbon nanotubes (MWCNTs) prepared from a simple solution using mixing method. We reported the structure change of NRL upon addaing different contenets of MWCNTs. The results from the X-ray diffraction, Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed that the nanocomposites have been successfully prepared, making them fitting to impact significant improvement on the mechanical strength of the matrix. The frequency dependence of the dielectric constant, dielectric loss and AC conductivity of the NRL/MWCNTs nanocomposites at room temperature under different nanotube loading conditions were invistgated. The radiation shielding characteristics such as the linear attenuation coefficients (l) and half-value thickness for NRL/MWCNTs nanocomposite films were presented.Thus, from the obtained results, it can be concluded that nanocomposite films offer promising radiation-shielding properties.

Flexible and High-Performance Electromagnetic Shielding Materials from Waste Polyurethane Foams

In the modern society, polymer composites utilizing various wastes for electromagnetic interference (EMI) shielding are of great economic and social significance. Herein, we report that waste polyurethane foams (WPUF) can be facilely converted into high-performance EMI shielding materials via surface coating of carbon nanotubes followed by hot pressing. The merit of this work lies in the novel skin-core segregated structure from the complete three-dimensional skeleton of WPUF, which is well retained after compression molding. The uniform distribution of multiwalled carbon nanotubes (MWCNTs) on the polyurethane skeleton surface assisted by cellulose nanofibers (CNFs) provides the material with remarkable electrical conductivity, leading to excellent EMI shielding properties. The resultant composite (WPUF-MC) achieves a high EMI shielding effectiveness (SE) of 63.2 dB at a low loading of MWCNTs (6.6 wt %), far surpassing the values for many early reported shielding materials of this kind. Moreover, the WPUF-MC also exhibits sufficient flexibility and reliable EMI shielding performance. Even if bent or twisted 1000 times, it can still maintain EMI SE at a fairly high level. This work not only offers an effective strategy for high-value utilization of WPUF but also may expand the application potential of flexible shielding materials.

Nano CuO-embedded polyaniline films as efficient broadband electromagnetic shields

Electromagnetic interference (EMI) is the undesirable consequence of advances in electronic technology and is perilous to the proper working of electronic devices, the environment and health. Shielding materials capable of curbing the ill effects of stray radiation are widely employed in electronic circuits and sensitive devices. Conducting polymers are excellent candidates due to their intriguing and tunable electronic properties. They offer high scope for designing and developing lightweight shields with performance efficiency much superior to their metallic counterparts. The present work highlights the development of high dielectric constant, micrometre thin films of polyaniline/cupric oxide (PANI/CuO) nanocomposites capable of attenuating more than 99.99% of the incident electromagnetic radiation over a broad frequency range. The best performing hybrid film show maximum absorption coefficients (A) close to 0.5 (where R = 0.5) in the S-band and around 0.92 (where R = 0.08) in the X-band frequencies. Incredible shielding effectiveness values as high as 83 dB at par with commercial standards are realised in micrometre thick films, offering ample scope for designing cost-effective, highly efficient and flexible shields.

Improving the Density of Functional Fabrics to Protect Radiation Workers in Radiology Departments

In medical institutions, the high weight of shielding clothing restrains the activities of medical workers. Although lightweight shielding clothing is being manufactured to solve this problem, the weight can only be reduced by 10%–20%. Flexible shielding fibers are mainly used to minimize activity restrictions; however, it is difficult to maintain the reproducibility of shielding performance. When weaving fibers with a yarn that contains a shielding material, the content of the shielding material in the yarn, tensile strength, and problems encountered during weaving should be considered. Therefore, in this study, a high-density shielding fabric weaving process was developed to weave a functional shielding fabric for actively utilizing it for low-dose shielding. The yarn was manufactured using 5 wt% barium sulfate, and the shielding performance was evaluated using the existing plain weave and two fabrics that underwent the newly developed high-density twill weave process. As a result of the experiment, the density of the fabric woven by the twill method increased by 82 g/m³, documenting a difference of 7.46% in the high-energy region and 11.71% in the low-energy region, thus indicating that the Twill method improves the shielding effect. Therefore, it is possible to mass produce lightweight, high-density shielding fabric that can protect against scattered rays that represent the main source of radiation in medical institutions.