Shielding Effect Research Articles

Interfacial Domino Effect Triggered by β-Alanine Cations Realized Highly Reversible Zinc-Metal Anodes.

Realizing durative dense, dendrite-free, and no by-product deposition configuration on Zn anodes is crucial to solving the short circuit and premature failure of batteries, which is simultaneously determined by the Zn interface chemistry, electro-reduction kinetics, mass transfer process, and their interaction. Herein, this work unmasks a domino effect of the β-alanine cations (Ala+) within the hydrogel matrix, which effectively triggers the subsequent electrostatic shielding and beneficial knock-on effects via the specifical adsorption earliest event on the Zn anode surface. The electrostatic shielding effect regulates the crystallographic energetic preference of Zn deposits and retards fast electro-reduction kinetics, thereby steering stacked stockier block morphology and realizing crystallographic optimization. Meanwhile, the mass transfer rate of Zn2+ ions was accelerated via the SO4 2- anion immobilized caused by Ala+ in bulk electrolyte, finally bringing the balance between electroreduction kinetics and mass transfer process, which enables dendrite-free Zn deposition behavior. Concomitantly, the interfacial adsorbed Ala+ cations facilitate the electrochemical reduction of interfacial SO4 2- anions to form the inorganic-organic hybrid solid electrolyte interphase layer. The above domino effects immensely improve the utilization efficiency of Zn anodes and long-term stability, as demonstrated by the 12 times longer life of Zn||Zn cells (3650 h) and ultrahigh Coulombic efficiency (99.4 %).

Harnessing Ion‐Dipole Interactions for Water‐Lean Solvation Chemistry: Achieving High‐Stability Zn Anodes in Aqueous Zinc‐Ion Batteries

AbstractThe reversibility and stability of aqueous zinc‐ion batteries (AZIBs) are largely limited by water‐induced interfacial parasitic reactions. Here, dimethyl(3,3‐difluoro‐2‐oxoheptyl)phosphonate (DP) is introduced to tailor primary solvation sheath and inner‐Helmholtz configurations for robust zinc anode. Informed by theoretical guidance on solvation process, DP with high permanent dipole moments can effectively substitute the coordination of H2O with charge carriers through relatively strong ion‐dipolar interactions, resulting in a water‐lean environment of solvated Zn2+. Thus, interfacial side reactions can be suppressed through a shielding effect. Meanwhile, lone‐pair electrons of oxygen and fluorinated features of DP also reinforce the interfacial affinity of metallic zinc, associated with exclusion of neighboring water to facilitate reversible zinc planarized deposition. Thus, these merits endow the Zn anode with a high‐stability performance exceeds 3800 hours at 0.5 mA cm−2 and 0.5 mAh cm−2 for Zn||Zn batteries and a high average Coulombic efficiency of 99.8 % at 4 mA cm−2 and 1 mAh cm−2 for Zn||Cu batteries. Benefiting from the stable zinc anode, the Zn||NH4V4O10 cell maintains 80.3 % of initial discharge capacity after 3000 cycles at 5 A g−1 and exhibits a high retention rate of 99.4 % against to the initial capacity during the self‐discharge characterizations.

Interfacial Domino Effect Triggered by β‐Alanine Cations Realized Highly Reversible Zinc‐Metal Anodes

AbstractRealizing durative dense, dendrite‐free, and no by‐product deposition configuration on Zn anodes is crucial to solving the short circuit and premature failure of batteries, which is simultaneously determined by the Zn interface chemistry, electro‐reduction kinetics, mass transfer process, and their interaction. Herein, this work unmasks a domino effect of the β‐alanine cations (Ala+) within the hydrogel matrix, which effectively triggers the subsequent electrostatic shielding and beneficial knock‐on effects via the specifical adsorption earliest event on the Zn anode surface. The electrostatic shielding effect regulates the crystallographic energetic preference of Zn deposits and retards fast electro‐reduction kinetics, thereby steering stacked stockier block morphology and realizing crystallographic optimization. Meanwhile, the mass transfer rate of Zn2+ ions was accelerated via the SO42− anion immobilized caused by Ala+ in bulk electrolyte, finally bringing the balance between electroreduction kinetics and mass transfer process, which enables dendrite‐free Zn deposition behavior. Concomitantly, the interfacial adsorbed Ala+ cations facilitate the electrochemical reduction of interfacial SO42− anions to form the inorganic‐organic hybrid solid electrolyte interphase layer. The above domino effects immensely improve the utilization efficiency of Zn anodes and long‐term stability, as demonstrated by the 12 times longer life of Zn||Zn cells (3650 h) and ultrahigh Coulombic efficiency (99.4 %).

An Experimental Study on Electromagnetic Shielding Effectiveness and Impact Resistance of UHPC for Protective Facilities

The research was conducted on incorporating short carbon fiber and multi-layer graphene into ultra-high performance concrete (UHPC) to improve the dynamic mechanical performance and electromagnetic shielding effectiveness (SE). In the electromagnetic shielding effectiveness testing, the results shown that UHPC with uniformly distributed conductive fibers exhibited superior shielding effectiveness at high frequencies. In comparison to normal concrete, the UHPC demonstrated the capability to withstand higher impact energy. Simultaneously enhancing both electromagnetic shielding characteristics and dynamic mechanical performance of cementitious materials can be challenging. In this study, employing a composite structure was effective solution to overcome this issue. In accordance with the experimental results, a scaled testing protective facility has been constructed, and the research results could provide the reference for the design and construction of protective structures.

Employing shielding effect of intercalated cinnamate anion in NiFe LDH for stable and efficient seawater oxidation

Seawater electrolysis is a valuable and promising method for clean hydrogen generation. The corrosion induced from active anions in seawater and the competition between oxygen evolution reaction (OER) and chloride evolution reaction (CER) limit the overall efficiency of seawater electrolysis. Herein, shielding strategy was introduced with cinnamate anion (CNA) intercalated in NiFe LDHs (NiFe LDHCNAs) for efficient alkaline seawater oxidation. It displays an outstanding OER performance with 247 mV and 258 mV to achieve the current density of 50 mA/cm2 in 1 M KOH electrolyte and alkaline seawater (1 M KOH + real seawater), respectively. Meanwhile, CNA-NiFe LDH presents excellent durability (over 72 h at 100 mA/cm2) in 1 M KOH electrolyte and alkaline seawater. The enhanced catalytic performance and durability can ascribe to the enlarged interlayer spacing by CNA intercalation and shielding effect of CNA against chlorine corrosion. This research offers a novel approach to the design of efficient electrocatalysts for hydrogen production from seawater electrolysis.

Ultrafine Aramid Nanofiber-Assisted Large-Area Dense Stacking of MXene Films for Electromagnetic Interference Shielding and Multisource Thermal Conversion.

Polymers are often used as adhesives to improve the mechanical properties of flexible electromagnetic interference (EMI) shielding layered films, but the introduction of these insulating adhesives inevitably reduces the EMI performance. Herein, ultrafine aramid nanofibers (UANF) with a diameter of only 2.44 nm were used as the binder to effectively infiltrate and minimize the insulating gaps in MXene films, for balancing the EMI shielding and mechanical properties. Combining the evaporation-induced scalable assembly assisted by blade coating, flexible large-scale MXene/UANF films with highly aligned and compact MXene stacking are successfully fabricated. Compared with the conventional ANF with a larger diameter of 7.05 nm, the UANF-reinforced MXene film exhibits a "brick-mortar" structure with higher orientation and compacter stacking MXene nanosheets, thus showing the higher mechanical properties, electrical conductivity, and EMI shielding performance. By optimizing MXene content, the MXene/UANF film can achieve the optimal tensile strength of 156.9 MPa, a toughness of 2.9 MJ m-3, satisfactory EMI shielding effectiveness (EMI SE) of 40.7 dB, and specific EMI SE (SSE/t) of 22782.4 dB cm2/g). Moreover, the composite film exhibits multisource thermal conversion functions including Joule heating and photothermal conversion. Therefore, the multifunctional MXene/UANF EMI shielding film with flexibility, foldability, and robust mechanical properties shows the practical potential in complex application environments.

Synthesis of functionalized hyperbranched polyethylene with high density polar groups using triarylnaphthyl iminopyridyl palladium catalysts

The 8-arylnaphthalenyl substituent is widely used as an effective chain transfer retarding substituent in late-transition-metal-catalyzed ethylene (co)polymerization. In this contribution, we introduce a new class of palladium catalysts based on 2,4,8-triarylnaphthyliminopyridyl ligands to provide an effective shield on the axial site of the active center. This results in the production of high molecular weight polyethylene or functionalized polyethylene. The palladium catalysts exhibit moderate polymerization activity (104 g mol−1 h−1) in ethylene polymerization. The resulting polyethylene has high molecular weights (16.8–60.8 kg/mol) and high branching densities (90–96/1000C). These catalysts are highly efficient for ethylene and MA copolymerization, enabling access to high molecular weight functionalized polyethylene with a remarkable MA incorporation ratio (9.21–21.00 mol%) under very mild conditions. According to the 13C NMR analysis, it was found that the polyethylene and E-MA copolymers were hyperbranched. In comparison to previously reported iminopyridine palladium catalysts with similar structures, catalysts in this work demonstrated reduced activity and exhibited a relatively high molecular weight, alongside achieving the highest insertion ratio in ethylene (co)polymerization.

Absorption-dominant electromagnetic interference shielding material using MXene-coated polyvinylidene fluoride foam

MXene (Ti3C2Tx), known for its exceptional electrical conductivity, unique two-dimensional structure, extensive surface functionality, and hydrophilicity, has emerged as a leading candidate for electromagnetic interference (EMI) shielding applications. Despite these excellent characteristics, EMI shielding materials based on MXene mostly utilize the reflection mechanism, which may cause secondary interferences. This study introduces an approach to utilize MXene as absorption-dominant EMI shielding materials. By engineering a porous layer of polyvinylidene fluoride (PVDF) atop MXene nanoflakes, we achieved a synergistic enhancement in EMI shielding effectiveness (SE) and absorptivity. The PVDF foam serves as an effective impedance matching layer, substantially enhancing the absorption of electromagnetic waves into the shielding material. Incorporating electrically conductive MXene nanoflakes to form a thin film creates a robust conductive network, fully leveraging its inherent performance. This network efficiently dissipates EM waves, thereby significantly enhancing the EMI SE. The shielding performance of this composite was thoroughly evaluated across both the X-band (8.2 GHz–12.4 GHz) and the Ka-band (26.5 GHz–40 GHz) frequencies. It demonstrated high EMI SE, attributed to mechanisms predominantly based on absorption. Specifically, it achieved an EMI SE of approximately 63.3 dB with high absorptivity (0.74) in the X-band and approximately 73.3 dB with high absorptivity (0.85) in the Ka-band. These findings underscore its potential as a route to develop absorption-dominant EMI shielding materials.

Design of 3D printing osteotomy block for foot based on triply periodic minimal surface

The ankle joint, which connects the lower limbs and the sole of the foot, is prone to sprain during walking and sports, which leads to ankle arthritis. Supratroleolar osteotomy is an ankle preserving operation for the treatment of ankle arthritis, in which the osteotomy is an important fixing and supporting part. In order to avoid stress shielding effect as much as possible, the osteotomy block is designed as a porous structure. In this study, the osteotomy block was designed based on three-period minimal surface, and the designed structure was manufactured by 3D printing. The mechanical properties of different structures were studied by mechanical test and finite element simulation. In mechanical tests, the Gyroid structure showed a progressive failure mechanism from bottom to bottom, while the Diamond structure showed a shear failure zone at 45° Angle, which was not conducive to energy absorption and was more prone to brittle fracture than the Gyroid structure. Therefore, the Gyroid structure is valuable for further research in the development of porous osteotomy.

Responsive aerogels of ultra-light flexibility and Fouling-Resistant characteristics to safeguarding X-ray exposure

The extensive application of X-rays has catalyzed a significant increase in the demand for secure work attire and safeguarding fabric materials. Nonetheless, the current Pb-infused materials employed for X-ray protection are generally hefty, rigid, and biohazardous, which substantially restrict their utilization in wearable contexts. In this work, a series of sustainable, ultralight, highly elastic and harmless X-ray protection aerogel is demonstrated and structured as a fusion of bacterial cellulose/Bi2O3 nanoparticles and Gd2O3 nanosheets. The cooperative shielding effect against X-rays, resulting from multilevel scattering and absorption by Bi/Gd elements, substantially boosts the protective efficiency of aerogels. Moreover, the polymorphic nanoparticles and robust nanofibrous networks provide these aerogels with exceptional flexibility. The as-designed aerogels exhibit integrated properties of superior mass attenuation coefficient (6.1 cm2 g−1), ultralow density (11.07 mg cm−3), good compression resilience, and low pressure drop (0.2 kPa at 3.0 cm s−1). The rational-designing of such innovative aerogels opens up pathways for the development of future effective and wearable materials for X-ray protection.

Facile preparation of conductive silicone rubber composite foams with tunable cell morphologies and absorption-dominant characteristics

Flexible silicone rubber (SR) foams with tunable cellular morphologies were fabricated via supercritical CO2 foaming. Conductive carbon black (CB) modified at a low cost and with high complex viscosity was preferentially selected. The effects of the pore size and void fraction on the electrical conductivity and dielectric permittivity of the SR/CB composite foams were carefully investigated. The pore size of the foams affected the specific shielding effectiveness (SSE) and absorption coefficient (A), whereas the variation in the void fraction did not generate evident changes. In comparison with its solid counterpart, a foam with a pore diameter of 59.9 μm showed a 50 % decrease in density, 31.6 % increase in absorptivity, and 95.7 % increase in SSE, demonstrating a considerable electromagnetic interference shielding effectiveness (EMI SE). Decreases in the pore size and void fraction of the foams improved compression modulus and strength. In addition, sample preparation process was simplified, making industrial production easier.

Study on the rheological properties and salt resistance mechanism of an amphiphilic polymer with twin-tailed group

Partially hydrolyzed polyacrylamide (HPAM) is the most widely used polymer for oil recovery. Its thickening ability has been severely compromised in high salinity reservoirs. To improve polymer viscosity in high salinity reservoirs, a twin-tailed amphiphilic polymer P(AM/AMPS/DtC18) was developed by radical copolymerization method using AM, AMPS and DtC18 monomers, abbreviated as PAAD18. The contrast polymer P(AM-AMPS) was prepared by the same method and reaction conditions. The structure of PAAD18 was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and H Nuclear Magnetic Resonance Spectra (1H NMR). The relationship between its rheological properties and microstructure was studied using rheological analysis and Scanning Electron Microscope (SEM). The mechanism of salt resistance was revealed. The results show that under the condition of XJ reservoir with 98558 mg/L and 40℃, the viscosity of PAAD18 with concentration of 2200 mg/L is 25 mPa·s. PAAD18 has better temperature and salt resistance than HPAM and P(AM-AMPS). P(AM-AMPS) has better temperature resistance and salt resistance than HPAM. The salinity ranges from 0 to 5 × 104 mg/L, the viscosity of PAAD18 is reduced due to the action of electrostatic shielding. At a salinity of 5 × 104 mg/L, the electrostatic shielding effect and the hydrophobic association effect reach a balanced point, and the solution viscosity is the lowest. The salinity increases from 5 × 104 mg/L to 15 × 104 mg/L, then the hydrophobic association is enhanced due to the increased polarity of the solution. It was found that the polymer network structure of PAAD18 was more complex, the viscosity of the solution increased instead. The salt thickening properties were demonstrated in the rheology measurement. This work provides a new material for polymer flooding technology in high salinity reservoirs, with good application potential and guiding significance.

Biomimetic Mechanical Robust Cement-Resin Composites with Machine Learning-Assisted Gradient Hierarchical Structures.

Biological materials relying on hierarchically ordered architectures inspire the emergence of advanced composites with mutually exclusive mechanical properties, but the efficient topology optimization and large-scale manufacturing remain challenging. Herein, this work proposes a scalable bottom-up approach to fabricate a novel nacre-like cement-resin composite with gradient brick-and-mortar (BM) structure, and demonstrates a machine learning-assisted method to optimize the gradient structure. The fabricated gradient composite exhibits an extraordinary combination of high flexural strength, toughness, and impact resistance. Particularly, the toughness and impact resistance of such composite attractively surpass the cement counterparts by factors of approximately 700 and 600 times, and even outperform natural rocks, fiber-reinforced cement-based materials and even some alloys. The strengthening and toughening mechanisms are clarified as the regional-matrix densifying and crack-tip shielding effects caused by the gradient BM structure. The developed gradient composite not only endows a promising structural material for protective applications in harsh scenarios, but also paves a new way for biomimetic metamaterials designing.

Cellulose–derived carbon scaffolds with bidirectional gradient Fe3O4 distribution: Integration of green EMI shielding and thermal management

Cellulose papers (CPs) possess a pore structure, rendering them ideal precursors for carbon scaffolds because of their renewability. However, achieving a tradeoff between high electromagnetic shielding effectiveness and low reflection coefficient poses a tremendous challenge for CP-based carbon scaffolds. To meet the challenge, leveraging the synergistic effect of gravity and evaporation dynamics, laminar CP-based carbon scaffolds with a bidirectional gradient distribution of Fe3O4 nanoparticles were fabricated via immersion, drying, and carbonization processes. The resulting carbon scaffold, owing to the bidirectional gradient structure of magnetic nanoparticles and unique laminar arrangement, exhibited excellent in-plane electrical conductivity (96.3 S/m), superior electromagnetic shielding efficiency (1805.9 dB/cm2 g), low reflection coefficients (0.23), and a high green index (gs, 3.38), suggesting its green shielding capabilities. Furthermore, the laminar structure conferred upon the resultant carbon scaffold a surprisingly anisotropic thermal conductivity, with an in-plane thermal conductivity of 1.73 W/m K compared to a through-plane value of only 0.07 W/m K, confirming the integration of thermal insulation and thermal management functionalities. These green electromagnetic interference shielding materials, coupled with thermal insulation and thermal management properties, hold promising prospects for applications in sensitive devices.

Modulation of the electromagnetic shielding effectiveness through micro/macrostructure design for electronic packaging

Lightweight electronic packaging that provides mechanical protection, cooling ability, and customizable electromagnetic interference (EMI) shielding effectiveness (SE) is needed for next-generation electronics. Although electronic packaging solutions with excellent EMI SE exist, there is limited research on how hierarchical design can modulate the EMI SE of an electronic packaging material on demand. In this study, the deliberate precise micro/macrostructure design of graphite-based materials using magnetically assisted 3D printing allows tuning of the EMI SE in the X band (8–12 GHz), leading to a maximum total shielding performance of 90 dB. Aligning high-density graphite microplatelets during 3D printing also remarkably amplified the total SE by 200%. Subsequently, rationally designing the oriented microstructure within a geometrical shape increases the reflection and improves the EMI SE from 40 to 60 dB in a specific direction. Our proof-of-concept samples demonstrate the potential of precise micro/macrostructure design for customizing and enhancing electronic packaging’s EMI SE while achieving good heat dissipation and mechanical protection using a versatile 3D printing method. These advances pave the way for more reliable and safer electronic systems.

BST@Copper Nanowire/Epoxy composites with excellent microwave absorption in the X-band

In this work, hybrid epoxy nanocomposites containing varying loading of copper nanowires (CuNW), Ba0.7Sr0.3TiO3 (BST), and BST@CuNW hybrid nanoparticles were prepared and analyzed for their microwave absorption characteristics. The nanoparticles used in this study were prepared using a facile co-precipitation and hydrothermal methodology. The synthesized nanoparticles were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) for their morphology and phase determination. While the XRD results confirmed the presence of BST and CuNW, the SEM micrographs obtained on the hybrid BST@CuNW nanoparticles show BST anchored on the CuNW surfaces. A series of epoxy composites containing varying loading of synthesized nanoparticles were prepared and characterized for their microwave properties, such as complex permittivity, shielding effectiveness, and power coefficients. The results indicate that nanocomposites containing BST@CuNW hybrids exhibited enhanced dielectric loss and more significant microwave power absorption compared to samples with equivalent CuNW and/or BST loading. The best composite sample, i.e., a one-millimeter-thick epoxy containing 10:15 (wt/wt) CuNW: BST hybrid nanoparticles with an estimated density of 1.49 g/cc attenuated 99.1 % of incident microwave power and exhibited a shielding effectiveness value of 21.2 dB in the X-band (8–12 GHz) of the microwave frequency spectrum. These lightweight polymer composites with high microwave absorption in the X-band are useful for military and civilian applications.

Wind-induced interference effect of complex building clusters on long-span roof structures

The presence of complex buildings introduces interference effects and complicates the wind field around the long-span roof structure. The complexity of the problem makes it challenging to predict wind load of long-span roof structures, resulting in a scarcity of design data available to engineers and designers. Thus, the influence of interference effect on mean and peak pressure coefficients of a long-span tri-centered cylindrical roof structure was investigated through wind tunnel tests conducted in an atmospheric boundary layer wind tunnel. The study focused on the interference effects caused by two cooling towers, chimney, and some low-rise buildings, considering all wind directions. The results show that the interference effects are the result of a combination of amplification effects from the adjacent cooling towers and chimney and shielding effects from the surrounding low-rise buildings. Due to the shielding effect of low-rise buildings, the wind suction on the roof is mitigated compared to that of a single building, while at the end of the roof, wind suction is amplified by cooling tower effects. The interference effect of the building clusters, however, amplifies the fluctuating wind pressure coefficient and the peak pressure coefficient on the roof. To accurately estimate the wind load of building components and envelopes, furthermore, this study investigates the influence mechanism of interference effect on non-Gaussian characteristics of wind pressure combining with fluctuating wind pressure spectrum, spatial correlation of fluctuating wind pressure, and probability distribution characteristics of standardized wind pressure coefficient. The spatial correlation of wind pressure in the roof interference area exhibits a strong association, and the probability density distribution characteristics of the standardized wind pressure coefficient significantly deviate from the Gaussian curve, with a peak factor exceeding 3.5. Thus, it can be concluded that the wind pressure within this region demonstrates significant non-Gaussian characteristics. Hence, the zone values of peak pressure coefficients are determined using the peak factor approach to inform the wind resistance design of the envelope structure.

X- and gamma rays cross sections and nuclear shielding performance of recycled cathode ray tube doping with high concentrations of Na2CO3

In an attempt to mitigate the increasing number of waste Cathod Ray Tube (CRT) glass in the environment, provide a safe, cheaper, and environmentally attractive recycling route for the glasses, and provide an alternative material for gamma radiation absorption applications, this study investigated the influence of adding Na2CO3 on the density, and gamma photon-absorbing prowess of CRT glass. Using the powder metallurgy process, CRT-NCx glasses consisting of CRT glass powder mixed with two distinct weight concentrations (20% (CRT-NC20 and 40% (CRT-NC40)) of Na2CO3 powder were prepared. The mass attenuation coefficients (μρ) of the prepared glasses were obtained using FLUKA simulations for 15 keV–15 MeV photons. The density of CRT, CRT-NC20, and CRT-NC40 were 3.117 g/cm3, 2.987 g/cm3, and 2.894 g/cm3, respectively. The range of μρ for CRT, CRT-NC20, and CRT-NC40 corresponded to 0.0326–45.5236 cm2/g, 0.030–35.0662 cm2/g, and 0.0278–26.9813 cm2/g, respectively. The half-value layer and mean free path was found to vary within the range 0.005–6.822 cm and 0.007–9.842 cm for CRT; 0.007–7.748 cm and 0.010–11.178 cm for CRT-NC20; and 0.009–8.633 cm and 0.013–12.455 cm for CRT-NC40. The minimum and maximum values of μenρ were 0.0216 and 37.7566 cm2/g for CRT, 0.0202 and 29.1167 cm2/g for CRT-NC20, and 0.01921 and 22.4430 cm2/g for CRT-NC40. CRT-rich glass showed higher radiation absorbed doses for the same beam energy and glass thickness. Na2CO3-rich glasses had lower buildup factors BFs, hence preferable in broad beam transmission scenarios. The investigated CRT-NCx glasses are more attractive for radiation protection functions in contrast to some well-known radiation shielding materials considering their lower mean free paths. The present glass system provides and alternative and effective gamma radiation shield, and also proffers a way of upcycling waste CRT glasses.

Predominance of Yb3+ and Ce3+ on the AlTaBaBO: Yb and BaTiSbBPO: Ce glasses for effective photoluminescence and radiation shielding properties towards w-LED and γ-ray shielding applications

Alumino tantalum barium borate - 65B2O3 +10Al2O3 +5SrCO3 +5BaCO3 +14Li2CO3 +4Ta2O5 +1Yb2O3 (AlTaBaBO: Yb) and barium antimony borophosphate - 35P2O5 +35B2O3 +10TiO2 +5 KF +10Li2CO3 +4SbO3 +1CeO3 (BaTiSbBPO: Ce) glasses were prepared using melt – quenching technique. The structural property of as-prepared glass materials is investigated by powder X–ray diffraction to identify the amorphous nature of the materials. FTIR and FT-Raman spectroscopic analyses examined various functional groups of glasses. The linear optical behaviours were characterized using UV–visible spectroscopy, and besides the different linear optical parameters such as refractive index and optical bandgap, optical conductivity was estimated. Excitation and emission spectra of the harvested glasses were characterized using a Photoluminescence spectrophotometer. Rare earth – R.E (Yb3+ and Ce3+) doped both glasses have greater emission efficiency due to their 2F7/2 → 2F5/2 (951 nm) and 5d1 → 2F5/2, 2F7/2 (550 and 663 nm) electronic transitions, which shows that the as-prepared glass materials have their potential applications. Colour chromaticity (CIE) diagrams of the cultivated glasses were examined with colour co – ordinations x = 0.3054, y = 0.2881 for AlTaBaBO: Yb and x = 0.3874, y = 0.3436 for BaTiSbBPO: Ce and the obtained outcomes confirmed w-LED device fabrication. Moreover, the various γ– ray shielding parameters were analyzed theoretically using Phy-X software. The five (a, b, c, d, and Xk) parameters of the Geometric Progression (G-P) fitting scheme were used to determine the energy-related energy buildup factor (EBF) as well as energy absorption buildup factor (EABF) of glasses in terms of infiltration deepness up to 40 mfp. At lower photon energy, the AlTaBaBO: Yb and BaTiSbBPO: Ce glasses have the highest μ/ρ values of 4.47 × 105 cm2/g and 3.864 × 103 cm2/g, respectively. For AlTaBaBO: Yb and BaTiSbBPO: Ce glasses, the calculated mean free path (MFP) values at 15 MeV photon energy are 0.143 cm and 12.18 cm, respectively. The result of all findings reveals that the synthesised glasses are viable materials for the futuristic utilization of w-LED and neutron radiation shielding applications.

Petal-Shaped Graphene Porous Films with Enhanced Absorption-Dominated Electromagnetic Shielding Performance and Mechanical Properties.

The absorption-dominated graphene porous materials, considered ideal for mitigating electromagnetic pollution, encounter challenges related to intricate structural design. Herein, petal-like graphene porous films with dendritic-like and honeycomb-like pores are prepared by controlling the phase inversion process. The theoretical simulation and experimental results show that PVP K30 modified on the graphene surface via van der Waals interactions promotes graphene to be uniformly enriched on the pore walls. Benefiting from the regulation of graphene distribution and the construction of honeycomb pore structure, when 15 wt % graphene is added, the porous film exhibits absorption-dominated electromagnetic shielding performance, compared with the absence of PVP K30 modification. The total electromagnetic shielding effectiveness is 24.1 dB, an increase of 170%; the electromagnetic reflection coefficient reduces to 2.82 dB; The thermal conductivity reaches 1.1 W/(m K), representing a 104% increase. In addition, the porous film exhibits improved mechanical properties, the tensile strength increases to 6.9 MPa, and the elongation at break increases by 131%. The method adopted in this paper to control the enrichment of graphene in the pore walls during the preparation of honeycomb porous films by the phase inversion method can avoid the agglomeration of graphene and improve the overall performance of the porous graphene porous films.