Journals
2025 EN
Sahu Pabitra Kumar · Hiremath Somashekhar S.
In this article, lattice structures inspired by the shape of butterfly wings are proposed. The butterfly wing‐inspired lattice structures (BFS) are 3D‐printed using thermoplastic polyurethane (TPU) material through the fused filament fabrication (FFF) technique. The parametric studies are conducted to investigate the effects of various factors, including strut thickness, unit cell size, loading direction, angles, and functional grading, on key properties, such as energy absorption, specific energy absorption, average plateau stress, and elastic modulus of the BFS structure. The performance of the BFS structure is compared with that of another bioinspired lattice, derived from the cross section of a seagull feather shaft (SFS), and it was found that the BFS structure exhibits superior energy absorption capacity. Furthermore, the BFS structure's performance is compared against other lattice structures previously discussed in the literature, revealing its higher energy absorption capacity. Additionally, the reusability of TPU‐based lattice structures is assessed through cyclic loading tests. The butterfly‐shaped lattice structure demonstrates continuous energy absorption even after complete failure, indicating its durability and effectiveness in energy dissipation. Due to its enhanced energy absorption capacity, the BFS structure holds promising potential for use in protective applications such as helmets, armor, and footwear insoles.
Journals
2025 EN
Sahu Kundan Lal · Venkatesh Kurva · Kumar Anil
+4 more
The present work examines how varying aluminum content influences the structure, strength, and wear response of Al X MoNbTiV refractory high‐entropy alloys (HEAs) ( x = 0, 0.5, and 1). X‐ray diffraction confirms that all three compositions retain a body‐centered cubic solid‐solution matrix, while the lattice constant contracts slightly from 3.26 Å for the base alloy to 3.251 Å when Al reaches one atomic ratio. Al addition also refines the dendritic solidification pattern and promotes more uniform elemental distribution. Mechanical tests reveal a pronounced rise in yield strength, increasing from about 902 MPa in the Al‐free alloy to roughly 1.59 GPa at x = 1, but this strengthening is accompanied by a reduction in compressive strain at fracture from nearly 40% to about 11%. Hardness follows a similar upward trend with Al addition. Dry‐sliding wear experiments demonstrate that the alloys containing Al show more than a 30% decrease in wear rate relative to MoNbTiV. This result is attributed to higher hardness, microstructural refinement, and the formation of stable surface oxides during sliding. These outcomes highlight the potential of carefully tuned Al additions to produce lightweight, oxidation‐resistant refractory HEAs with a favorable balance of mechanical performance and surface durability for demanding high‐temperature applications.
Journals
2025 EN
AymerichArmengol Raquel · VegaParedes Miquel · Wang Zhenbin
+11 more
Abstract Molybdenum disulfide (MoS 2) nanostructures are promising catalysts for proton‐exchange‐membrane (PEM) electrolyzers to replace expensive noble metals. Their large‐scale application demands high activity for the hydrogen evolution reaction (HER) as well as robust durability. Doping is commonly applied to enhance the HER activity of MoS 2 ‐based nanocatalysts, but the effect of dopants on the electrochemical and structural stability is yet to be discussed. Herein, operando electrochemical measurements to the structural evolution of the materials down to the nanometric scale are correlated by identical location electron microscopy and spectroscopy. The range of stable operation for MoS 2 nanocatalysts with and without rhenium doping is experimentally defined. The responsible degradation mechanisms at first electrolyte contact, open circuit stabilization, and HER conditions are experimentally identified and confirmed with the calculated Pourbaix diagram of Re‐doped MoS 2 . Doping MoS 2 ‐based nanocatalysts is validated as a promising strategy for continuing the improvement of high‐performance and durable PEM electrolyzers.
Journals
2025 EN
Singh Nishikanta · Sinha Priyank · Sahu Bhanendra
+3 more
Abstract Sulfur dots (S‐dots) eliminate the need of expensive and toxic conventional photocatalysts or transition metal in photoinduced reversible deactivation radical polymerization (photoRDRP). Herein, non‐metallic S‐dots mediated photoRDRP of N,N‐dimethyl acrylamide (DMA) are developed for the first time. This technique allows for the precise synthesis of narrow‐dispersed poly(N,N‐dimethyl acrylamide) (PDMA) and double hydrophilic poly(N, N‐dimethyl acrylamide)‐ block ‐poly(2‐hydroxyethyl acrylamide) (PDMA‐ b ‐PHEAA) diblock copolymer suitable for contaminant removal from water. Also, its subsequent modification into a poly(N,N‐dimethyl acrylamide)‐ block ‐poly(N‐(2‐((4‐vinylbenzyl)oxy)ethyl)acrylamide) (PDMA‐ b ‐PVBEAA) diblock copolymer gives ultra‐fast gelation and production of writable ink‐gel, which is exceptionally well‐suited for 3D printing applications, enabling the creation of precise and defined shapes. This innovative material serves as an intriguing scaffold for tissue engineering and other biomaterial applications, especially in areas that demand rapid and customizable manufacturing solutions.
Journals
2025 EN
Sahu Alok Kumar · Padhan Aneeta Manjari · Radhakrishnan Abinath
+5 more
Abstract High entropy oxides have received widespread attention for their tunable structures and fascinating multifunctional properties. However, the systematic investigations of a number and the choice of oxides endow tunable entropy oxides (TEOs) with numerous untapped potentials, making them prospective future materials. In this article, the successful synthesis of TEOs is demonstrated, a pathway to design materials with giant dielectric (ε r ) by taking different numbers of oxides among MnO, NiO, Fe 2 O 3 , ZnO, and Al 2 O 3 , through a cost‐effective ball mill technique, followed by annealing and keeping the same crystal structure. All TEOs exhibiting A 3 O 4 type spinel structure with tunable mixed valence states remarkably display giant ε r of 6.85 × 10 7 , 8.66 × 10 7 , 4.59 × 10 6 , and 1.31 × 10 4 and tunable conductivity of 2.5 × 10 −5 , 3.7 × 10 −5 , 7.1 × 10 −6 , 2.4 × 10 −6 S cm −1 for TEO‐2, TEO‐3, TEO‐4, TEO‐5. Theoretical density functional analysis supports these superior properties. Among various triboelectric nanogenerator (TENG) devices, the TEO‐3‐based TENG produces high‐performance electrical output of 210–283 V, 0.2–0.291 µA, 18–27 nC, and 9.56–79.24 µW from various biomechanical activities. These results endorse the potential for sustainable energy harvesting, powering low‐power electronic devices, and enabling TEOs as candidates for triboelectric material.
Journals
2025 EN
Sahu Alok Kumar · Padhan Aneeta Manjari · Radhakrishnan Abinath
+5 more
Tunable Entropy Oxides In their Research Article ( 10.1002/adfm.202518131), Perumal Alagarsamy and co‐workers present a novel strategy to design and develop spinel‐structured tunable‐entropy‐oxides (TEOs) by increasing the number of oxide components from single to binary, ternary, quaternary, and ultimately quinary systems. Such advanced TEOs exhibit giant dielectric constants, tunable conductivity, and positive triboelectric properties, making them ideal for harvesting biomechanical energy in self‐powered applications.
Journals
2025 EN
Maity Swapan · Dubey Dipesh Kumar · Upreti Akshita
+8 more
Abstract Clinical oncology grapples with a daunting challenge therapy resistance in tumors evolves rapidly, undermining treatment efficacy. Chemotherapy, while inducing specific cancer cell death, often falls short due to intrinsic cellular defences. This underscores the urgent need for precision and controlled therapeutic strategies. A breakthrough emerges in tumor targeted drug delivery through interlamellar surface modification of hydroxyl groups in pristine Li‐Al‐based layered double hydroxide (LDH). Grafting polyurethane (PU) onto LDH enhances its mechanical integrity, achieving an extraordinary elongation at break of 1230%. This exceptional flexibility enables the material to withstand substantial deformation, ensuring adaptability within dynamic physiological environments – critical for injectable and implantable drug carriers navigating complex biological structures. The polyurethane graft fine‐tunes the hydrophilic hydrophobic balance, orchestrating synchronized drug delivery. First principle density functional theory (DFT) analyses reveal intricate molecular interactions between the nanohybrid and doxorubicin (Dox)In vitro and in vivo studies, particularly in luciferase – expressing melanoma‐bearing mice, demonstrate remarkable biocompatibility and synergistic anticancer efficacy. Furthermore, an injectable hydrogel beneath the tumor site mitigates chemotherapy's toxic side effects by precisely regulating drug release. This pioneering nanohybrid heralds a new era in multifunctional nanomedicine, offering enhanced precision, stability, and patient compatibility, transforming the landscape of next generation cancer therapies.
Journals
2025 EN
Hao Jing · Shukla Stuti · Gurnani Rishi
+9 more
Abstract The emergence of high‐density electronics in aerospace and renewable energies demands high temperature dielectrics. Molecular engineering represents a vital strategy for designing dielectric polymers, yet the influence of stereochemistry remains untapped. Herein, by designing halogen substituents of an aromatic pendant attached to a bicyclic mainchain, vicinal polydichloronorbornene (PDCNB) with a high glass‐transition temperature ( T g ) of 263 °C is obtained. Further study unveils the profound effect of stereochemistry on the properties of exo‐ and endo‐PDCNB. Both isomers show identical high T g and bandgap (4.3 eV), imparting PDCNBs with remarkable capacitive energy storage, outperforming existing polymers and nanocomposites with two orders of magnitude lower conduction at an ultra‐high temperature of 250 °C. Moreover, the effect of stereoisomerism is manifested in the differences in backbone spacing, π‐stacking, barrier height, and trap states, and the resulting distinct high field performance. Exo‐PDCNB displays an extremely low conduction of 6.8 × 10 −14 S m⁻ 1 at 200 m V m⁻ 1 and maintains a record charge‐discharge efficiency of 82% at 450 m V m⁻ 1 , while endo‐PDCNB exhibits a high breakdown strength of 600 m V m⁻ 1 with a remarkable discharged density of 4.47 J cm⁻ 3 , all at 250 °C. This study unleashes a stereochemistry‐based strategy with vicinal dichloro substitution to further boost the T g of polynorbornene for ultra‐high‐temperature applications.
Journals
2025 EN
Javed Umer · Tebyetekerwa Mike · Tang Cheng
+14 more
Abstract Two‐electron water oxidation reaction (2e‐WOR) to produce hydrogen peroxide (H 2 O 2 ) is an attractive anode reaction with several merits. It can be paired with several large‐scale cathode reactions that produce valuable chemical substances in an electrochemical cell. However, high‐performing and reliable 2e‐WOR anodic catalysts are yet to be fully developed. In this work, a rationally designed, inexpensive, robust, and selective graphite catalyst electrode is presented, made by following the key principle mechanisms of 2e‐WOR. First, an aerophilic graphite‐based electrode is created to leverage the challenges posed by the four‐electron WOR, where the generated O 2 from this reaction is kept onto the electrode surface to shift the O intermediates binding on graphite in the direction of improved H 2 O 2 generation. An initial improvement in H 2 O 2 selectivity of seven fold is observed, albeit with no improved H 2 O 2 generation rates. The stunted H 2 O 2 generation is ascribed to poor activity from pristine graphite, courtesy of less active sites and low intrinsic O 2 binding in the electrolyte environment. Second, to improve and balance graphite's activity and selectivity, the structure of graphite is altered via different elemental doping (with N, S, B, and P atoms), a method that allows the retention of the O 2 on the graphite surface. The super‐aerophilic B‐doped graphite catalyst (optimum) reaches a maximum Faraday efficiency (FE) of 60.6 ± 2.6% with a production rate of 26.7 ± 0.6 µmol min −1 cm −2 (85.9 ± 2.2 mA cm −2 partial current density) and excellent stability of over 120 h. In tandem, cathodic H 2 co‐production is demonstrated with an FE of above 90%. This approach demonstrates a rational approach to designing inexpensive and robust 2e‐WOR anode catalysts for H 2 O 2 and the possibility of its use in chemical co‐production at the cathode.
Journals
2025 EN
Roy Suman · Sahu Mousam Charan · Jena Anjan Kumar
+4 more
Abstract Memristors‐based neuromorphic devices represent emerging computing architectures to perform complex tasks by outpacing the traditional Von‐Neumann architectures in terms of speed, and energy efficiency. In this work, the resistive switching (RS) behavior of sol‐gel grown and ion‐irradiated BFO films is investigated under electrical stimulus. The Ag/BFO/FTO memristors emulate a combination of digital and analog RS behavior within a single device. The possible mechanism of analog digital hybridity is addressed by considering the formation of the conducting filament by oxygen vacancies, Ag + ions and Schottky barrier height modulation. The ion‐irradiated BFO samples are analyzed using the Raman, XRD, and XPS studies. To uphold bioinspired synaptic actions, crucial synaptic functionalities like pair‐pulse facilitation and long‐term potentiation/depression are effectively achieved. More intricate synaptic behaviors are also demonstrated such as spike‐time‐dependent plasticity and Pavlovian classical conditioning, which represent the prominent attributes of both learning and forgetting behavior. Additionally, high pattern recognition accuracy (96.1%) is achieved in an artificial neural network simulation by using the synaptic weights of the memristors. This synergistic effect of digital and analog RS in ion‐irradiated BFO can be beneficial for the emulation of complex learning behavior as well as its incorporation into low‐power neuromorphic computing.