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TiO? and ZnO based ternary nanocomposites coupled with gC?N? and tetra-amino zinc phthalocyanine for enhanced oxygen evolution reaction performance
Electrocatalytic water splitting is a sustainable approach to address the energy crisis driven by the rapid growth of global population. The development of affordable and efficient electrocatalysts is inevitable in advancing the field. In the current study, TiO2NPs-TAZnPC-gC3N4 (TiO2 nanoparticles, tetra amino zinc phthalocyanine, and gC?N?) and ZnONPs-TAZnPC-gC3N4 (ZnO nanoparticles, tetra amino zinc phthalocyanine, and gC?N?) ternary nanocomposites have been prepared using a dispersion method. The structural identity of nanoparticles and the effective incorporation of additional moieties into the final system are validated using powder X-ray diffraction analysis and confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Transmission electron microscopy (TEM) images reveal the sheet-like structures of gC3N4 and TAZnPC, decorated with spherical TiO2NPs and hexagonal ZnONPs. The prepared ternary composites are evaluated for their electrocatalytic water splitting performance. In particular, the electrocatalysts reveal excellent oxygen evolution reaction (OER) capabilities with overpotentials of 420 mV and 450 mV for TiO2NPs-TAZnPC-gC3N4 and ZnONPs-TAZnPC-gC3N4, respectively. 2025 Elsevier B.V. -
Construction of a waste-derived graphite electrode integrated IL/Ni-MOF flowers/Co3O4 NDs for specific enrichment and signal amplification to detect aspartame
A novel and cost-efficient electrochemical sensor was designed by immobilizing IL/Ni-MOF/Co3O4 nanodiamonds on the graphite (GE) electrode, marking the first application for the detection of aspartame. The graphite electrode was extracted and recycled from discharged batteries to serve as a working electrode. The nanocomposite features unique Co3O4 nanodiamonds, generated using Coriandrum sativum seed extract, alongside Ni-metal organic framework (MOF), which were synthesized through a solvothermal method. The conductivity and stability of the electrochemical sensor were enhanced through the incorporation of the ionic liquid (IL) ([BMIM][MeSO4]. The phytochemical profile of Coriandrum sativum seed extract, analyzed by GC-MS, identified key compounds involved in the synthesis of Co3O4 nanodiamonds. A comprehensive characterization of the nanocomposite was performed using UV-Vis, FTIR, DLS, Zeta potential, XRD, XPS, FE-SEM, TEM, optical profilometry, and AFM to confirm the structural and elemental modifications. Electrochemical characterization of the bare and modified electrodes was conducted through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The GE/IL/Ni-MOF/Co3O4 nanodiamonds modified electrode displayed enhanced electroanalytical performance for aspartame detection, characterized by signal amplification at +7.0 V. Quantitative analysis by Differential Pulse Voltammetry (DPV) and Square Wave Voltammetry (SWV) revealed a linear detection range of 315 M for aspartame. A comparison of SWV and DPV revealed superior analytical performance for SWV, with limit of detection (LOD) and limit of quantification (LOQ) values of 1.02 M and 3.1 M (R2 = 0.993) compared to 1.81 M and 5.5 M (R2 = 0.986) for DPV. This study reveals the excellent adsorption capabilities of Ni-MOF and Co3O4 nanodiamonds (Co3O4 NDs), attributed to their high porosity and large surface area, paving the way for the development of affordable sensing devices for artificial sweeteners. 2024 Elsevier B.V. -
Chaos in a triple diffusive system involving a viscoelastic fluid layer
This study investigates the linear and weakly nonlinear stability analysis in a Rayleigh-Bard configuration with a viscoelastic fluid layer influenced by two additional solutal components. The governing equations for both stationary and oscillatory convective regimes, and the critical point at which convection sets in is derived. The comparative analysis is performed for three different viscoelastic fluid models: Oldroyd-B, Maxwell, Rivlin-Ericksen fluid, along with the Newtonian fluid model. In weakly nonlinear stability analysis, a generalized eight-mode Lorenz model is developed that satisfies the general properties of a classical Lorenz model. From this reduced model, the critical points and Hopf-Rayleigh number, representing the initiation of chaos through Hopf bifurcation are determined. The Lyapunov exponents are used to characterize the chaotic, periodic and quasi-periodic motions of the system. The results show that the viscoelastic and triple diffusion parameters affect the initiation of convection and transition to chaos. It is also observed that the Maxwell fluid exhibits the earliest initiation of chaos and the Newtonian fluid the latest, with Oldroyd-B and Rivlin-Ericksen exhibiting intermediate behaviour. The presence of additional solutal concentrations delays the onset of chaotic motion. 2026 The Physical Society of the Republic of China (Taiwan). -
A study on regular and chaotic convection in an anisotropic porous cavity
The primary intent of the work is to investigate the linear and weakly nonlinear stability analyses of the BrinkmanBard convection (BBC) problem in a horizontal thermally-anisotropic porous enclosure with temperature-dependent uniform heat source/sink analytically by using a weighted residual Galerkin scheme. The linear stability analysis of the study reveals that the conductive system is stabilized by increasing anisotropy, Darcy number, and internal heat source strength. Three modal Lorenz model is derived by performing weakly nonlinear stability analysis using truncated Fourier series solutions. Equilibrium points of the Lorenz model and stability analysis is studied. The conductive equilibrium point (zero equilibrium point) is asymptotically stable and the eigenvalues are negative, whereas the convective equilibrium points (non-zero equilibrium points) are asymptotically stable up to a threshold Rayleigh number. Later, Hf bifurcation or chaotic motions sets in. The effect of an increase in the values of internal heat source and thermal anisotropic term delays the onset of the chaotic convection, whereas the Darcy number exhibits the opposite fashion. Further, the amount of heat transport is estimated at the lower boundary of an enclosure, and it is seen that the amount of heat transfer is maximum in the case of heat source, Darcy medium, and heterogeneous medium compared within the Brinkman medium in the presence of heat sink. 2025 The Physical Society of the Republic of China (Taiwan) -
Nonlinear steady Darcy-Bard convection problem: Revisit using the heatlines approach
The classical problem of Darcy-Bard convection(DBC) in enclosures is revisited using the method of heatlines to have a better perspective of the problem. General aspect ratio is chosen in the analysis which helps in obtaining the results of four different types of enclosures, viz., tall, square, shallow and very shallow. Three different water saturated porous media(WSPM) and their actual thermophysical properties are used in the computation of the results. The method of heatlines facilitates the observation of fluid and heat flow lines in order to have a good understanding of the dynamics. The neo-classical approach not only accurately predicts the critical Darcy-Rayleigh and wave numbers but also picturizes the heat flow of the problem in the most natural way. The Galerkin method is used in the paper for the normal and convective modes of convection yields accurate analytical results in the heatlines formulation. Theoretical expression to calculate the number of Bard cells that form in the system at onset is obtained by linear theory, and ranges of aspect ratio at which unicellular, two-cellular and multicellular convection are possible are determined and documented. The weakly non-linear stability analysis is performed to determine the heat transport. Among four considered enclosures, maximum heat transport is achieved in the case of a square enclosure. Out of three chosen WSPM, the water-saturated glass balls porous medium and the water-saturated aluminium-foam porous medium show most stable and least stable behaviours. Results obtained from the heatlines approach are validated by comparing with the results of the classical DBC problem in the case of a very shallow enclosure. From the study, we conclude that the square enclosure with water-saturated aluminium-foam porous medium has possible application in heat removal systems. 2025 The Physical Society of the Republic of China (Taiwan) -
Red emission in MoO3:Eu3+ nanobelts: Investigation on the photoluminescence quenching mechanism
MoO3:Eu3+ nanobelts were synthesized via the hydrothermal method with varying concentrations of europium doping. The investigation has examined the structural, morphological, optical, and photoluminescence characteristics of MoO3:Eu3+ nanophosphors. The XRD and Raman spectroscopy affirmed the orthorhombic structure of the synthesized nanostructures. FESEM depicts a nanobelt-like morphology and XPS studies confirmed the presence of Eu3+. A detailed analysis of the photoluminescence mechanism, concentration quenching, and quantum efficiency is presented in this study. Upon 302 nm excitation, red emission was observed along with concentration quenching effects. The optimized sample with the highest PL intensity (MoO3:Eu3+ 3 mol. %) was annealed at 600 C for 12 hrs. The PL intensity increased upon annealing, with the corresponding CIE coordinates (0.52, 0.29). The findings highlight the material's potential for use in display technologies and bioimaging phosphors. 2025 The Authors -
Exploring the influence of family relationship on students school well-being
The purpose of the study was to examine the potential significance of familial relationships in influencing adolescent students experiences of happiness within the school context, contributing to the broader discourse on fostering a supportive environment for youth development. The method in this research used a quantitative approach with a correlational design through a survey method. A sample of 715 higher secondary students, comprising 66 % girls and 34 % boys from Kerala, India, completed the family relationship questionnaire and students subjective well-being measure. The analysis used was Spearman's Correlation and Multiple Regression. Based on the analysis results, it was found that the three dimensions of family relationship are positively correlated with a sig value of < .01. Thus, Ha1 was accepted. Multiple regression results revealed that family coherence (p < .001) emerged as the most significant predictor of student subjective well-being among three dimensions of family relationship measures. Family expressiveness (p < .01) is the second most influential element on students school well-being. Meanwhile, the result shows that there is no conclusive evidence that family conflict has predictive significance. Thus, Ha 2 was accepted except family conflict dimension. It may be inferred that all aspects of family relationship are positively related to student well-being. However, only family coherence and expressiveness have a substantial impact on the well-being of Indian higher secondary students, but family conflict does not. 2025 Elsevier Ltd -
The impact of feedback mechanisms on RayleighBard penetrative convection in micro-polar fluids
This study examines the effects of feedback control and internal heat sources on the onset criterion of RayleighBard convection (RBC) in a horizontal Boussinesq micropolar fluid layer. A linear stability analysis, employing the Chebyshev pseudospectral method, is conducted to compute the eigenvalues and assess the stability of the system under varying conditions. The analysis considers several parameters, including heat conduction, coupling, couple stress, scalar controller gain, and internal heat sources. The findings reveal that the introduction of internal heat sources destabilizes the system, while the scalar controller gain significantly delays the onset of convection, thereby enhancing system stability. Additionally, it is demonstrated that an increase in both the coupling and heat conduction parameters contributes positively to system stabilization, whereas an increase in the couple stress parameter hastens the onset of convection. Notably, the investigation indicates that the system demonstrates greater stability when the boundary is heated from above as opposed to from below. These results provide crucial insights for the control of heat transfer in micropolar fluids and suggest that optimizing the scalar controller gain, along with careful tuning of other system parameters, can significantly enhance stability. The implications of this research are substantial for the design of efficient fluid dynamical systems, particularly in scenarios requiring precise control over temperature, pressure, and flow, such as those encountered in chemical processing, power generation, and manufacturing. 2025 Elsevier Ltd -
Rheostatic effect of a magnetic field on the onset of chaotic and periodic motions in a five-dimensional magnetoconvective Lorenz system
This paper deals with a weakly nonlinear study of two-dimensional RayleighBard magnetoconvection using a simplified five-dimensional Lorenz model. The governing equations of the system are nondimensionalized and formulated in terms of the stream function and the scalar magnetic potential. A five-modal Fourier truncation scheme is employed and the resulting equations are scaled to obtain a five-dimensional autonomous dynamical system. The Hopf-Rayleigh number, signifying Hopf bifurcation, is numerically evaluated from the analysis of weakly nonlinear stability. Chaotic and periodic motions are depicted by plotting bifurcation diagrams, largest Lyapunov exponent (LLE) diagrams and three-dimensional projections of the phase-space. For a fixed set of parameter values, increasing the strength of the applied magnetic field is found to increase the Hopf-Rayleigh number, thereby delaying the destabilization of the system's equilibrium points. It is shown that while low magnetic field strengths favor the onset of chaotic motion directly from the steady state, stronger magnetic field strengths favor the onset of periodic convection from the steady state prior to the appearance of chaotic motion. We observe here that the applied magnetic field regulates the onset of chaotic and periodic motions in the system and therefore, has a rheostatic control over chaotic and periodic behaviors. 2025 Elsevier Ltd -
Effect of samarium doping on structural properties and electronic structure of Bi0.5Na0.5TiO3ceramic with antimicrobial applications
The research work reports a systematic examination of structure, microstructure, electronic and local structure, optical and antimicrobial properties of Bi0.5Na0.5TiO3 (BNT) and Bi0.45Sm0.05Na0.5TiO3 (BSNT) ceramics manufactured by the solid-state route. The influence of a small amount of samarium (Sm) doping at the A-site of BNT matrix is examined using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, field emission-scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure spectroscopy (EXAFS), UVvis diffused reflectance spectroscopy (DRS), and antimicrobial analyses. XRD reveals single-phase rhombohedral structures with R3c space group. FTIR provides evidence for perovskite structures. Raman spectra illustrate three prominent vibrations, like Bi - O/Na - O, Ti - O vibrations of TiO6, and oxygen ion vibrations of the TiO6 octahedron of both samples. FESEM reveals better grain developments, and elemental confirmations are evident from EDS. The topographical and morphological studies, such as RMS and average roughness, skewness, and kurtosis, are conducted by AFM. XPS reveals dual oxidation states of Ti and Sm, and oxygen vacancies (OVs). A detailed analysis of the electronic structure is performed by examining the Bi L3-edge and Ti K-edge XANES spectra of BNT and BSNT, along with those of the model compounds. The Fourier transform of EXAFS analysis is conducted to probe the local structure, and extracted parameters, like coordination number (N), bond distance (R(), and Debye-Waller factor (?2), are analyzed. UVvis studies reveal a minute reduction in the band gap in BSNT. Impedance study shows the negative temperature coefficient of resistance (NTCR) responses. The antibacterial activities are examined by determining the minimum inhibitory concentration (MIC) and zone of inhibition (ZOI) caused by the materials, along with a control antibiotic, against a variety of bacterial strains. 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies. -
Structure-tuned Pr-doped NiFe2O4nanoceramics for enhanced pseudocapacitive performance: Insights from lattice distortion and charge transfer dynamics
In this study, Praseodymium-doped nickel ferrite (NiPrxFe2-xO4, x=0.000.02) nanoceramics were synthesized via an efficient solution combustion method to investigate the structural modifications and their impact on electrochemical performance. X-ray diffraction confirmed the formation of a single-phase cubic spinel structure across all compositions, with Pr3+substitution inducing measurable lattice distortions and variations in crystallite size. WilliamsonHall analysis revealed a doping-dependent microstrain, highlighting the role of Pr doping in tuning the structural framework. FTIR spectra further confirmed alterations in metaloxygen vibrations at tetrahedral and octahedral sites, supporting the lattice perturbations caused by ionic substitution. Electrochemical characterization using cyclic voltammetry, galvanostatic chargedischarge, and electrochemical impedance spectroscopy demonstrated superior pseudocapacitive behavior for the optimally doped sample (x=0.01), which exhibited a high specific capacitance of 69.2F/g and the lowest charge transfer resistance (0.30?). Scanning electron microscopy revealed a porous and roughened surface morphology in this composition, facilitating rapid ion diffusion and redox kinetics. This is quantitatively supported by a correlation between doping-induced lattice strain, crystallite size, and the resulting enhancement in charge transfer kinetics and redox-active site density. These findings position Pr-doped NiFe2O4nanoceramics as promising candidates for next-generation supercapacitor electrodes. 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies. -
Fluorescence bioimaging applications of europium-doped strontium aluminate nanoparticles
Fluorescence bioimaging is widely used for physiological studies to visualise intercellular molecular events due to its highly selective, sensitive, and non-destructive nature. However, its application in in vivo live imaging is often limited by the scarcity of biocompatible fluorescent probes possessing optimal properties. Our study focuses on developing europium-based nanoparticles for in vivo bioimaging, especially imaging of plants. Eu-doped strontium aluminate nanoparticles were synthesised through a conventional solid-state reaction. Structural characterisation of samples using XRD confirmed the prevalence of SrAl2O4 as the prominent phase. The FTIR spectrum, SEM and TEM images were recorded for further characterization. Photoluminescence studies showed orange red emission of sample. The antibacterial activity of the nanophosphors was studied, demonstrating no antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. Furthermore, in vitro cytotoxicity studies conducted using Neuro-2A cells showed no indications of cytotoxicity associated with europium doped strontium aluminate nanoparticles. When incorporated into the plant tissue culture medium, these nanoparticles were found to have no effect on seed germination and plant growth, and it demonstrated no phytotoxicity. Imaging studies have shown the uptake of nanoparticles by plants and their subsequent transport through the vascular system. Our results emphasise the direct integration of nanophosphors into plant tissues from the growth medium, eliminating the necessity for traditional staining methods in fluorescence bioimaging. Incorporation of nanophosphors into living organisms holds promise for non-invasive and long-term fluorescence imaging, with potential applications in biological studies and diagnostics. The outstanding fluorescence properties and biocompatibility of europium doped strontium aluminate nanoparticles broaden its potential for various applications in fluorescence bioimaging. 2024 Elsevier Ltd and Techna Group S.r.l. -
Cerium-doped Co3O4 spinel structures synthesized by modified combustion route as an excellent material for electrochemical applications
This work shed light on the impact of cerium doping on the structural and electrochemical features of Co3-xCexO4(x = 0, 0.02, 0.04) synthesized via a facile and cost-effective modified combustion route. The structural, morphological and compositional investigations unveiled the formation of nanocrystalline structures with promising morphologies. BET and XPS methodologies explored the materials' porosity and electronic state of the materials. The electrochemical performance of the synthesized materials was evaluated by Cyclic Voltammetry (CV) at various scan rates, Galvanostatic Charge-Discharge (GCD) at different current densities, and Electrochemical Impedance Spectroscopic (EIS) techniques. GCD studies depicted an exquisite specific capacitance of 498 Fg-1 for Co2.98Ce0.02O4 at a current density of 1 Ag-1 and it displayed a capacitance retention of 95 % for over 2000 GCD cycles further it retains up to 90 % even after 3000 GCD cycles at a current density of 1Ag-1 juxtapose to other compositions. Our work emphasizes the importance of the material for energy storage applications. 2024 Elsevier Ltd and Techna Group S.r.l. -
Blue LED photolytic method for the synthesis of 1,4-dihydropyridine derivatives from benzo [b]thiophene-2-carbaldehyde
This study presents a highly efficient and operationally simple protocol for synthesizing 1,4-dihydropyridine derivatives. The protocol uses an inexpensive and readily available photocatalyst Mn2(CO)10, which plays a crucial role in the single-pot, four-component reaction involving benzo [b]thiophene-2-carbaldehyde, malononitrile, dialkyl acetylene dicarboxylate, and anilines in a blue LED (400500 nm) photocatalytic technique. The reaction conditions include the use of blue LEDs, a lower catalyst load, and green solvents like dimethyl sulfoxide (DMSO) and water in a 1:1 ratio. The multicomponent photocatalytic approach negates the use of expensive catalysts and the necessity of multi-step routes, in addition to providing better atom economy and an easy work-up process, and it is environmentally benign. The derivatives were effectively synthesized in higher yields and characterized using 1H NMR, 13C NMR, and ESI-MS. The obtained 1,4 dihydropyridines also have tremendous capability for biological and pharmacological activities, opening exciting possibilities for future research and applications. 2025 -
Surface bound copper- grafted TiO2 nanocatalyst for carbon-sulfur cross coupling reaction
This study reports the synthesis of TiO2-based nanocatalyst for efficient diarylsulfide synthesis via Ullmann-type reaction strategy, addressing challenges in conventional methods that are reliant on toxic reagents and harsh reaction conditions. The nanocatalyst comprises an amine-functionalized TiO2 core followed by copper doping. This nanocatalyst demonstrates exceptional performance in cross coupling reactions under mild conditions, achieving yields up to 5098 % with broad-substrate scope. The pure products were characterized using 1H NMR, 13C NMR, FT-IR, and mass spectrometry. The catalyst's heterogeneous nature enables easy recovery and reuse for upto 5 cycles without any significant activity loss. The synthesized nanocatalyst was characterized using various characterization techniques such as FT-IR, TGA, XRD, EDX, SEM, and STEM. This approach aligns with the green chemistry principles, minimizing waste and energy consumption and replacing highly expensive transition metal catalysts. The work highlights the potential of functionalized TiO2 nanomaterials in sustainable organic synthesis, contributing to SDGs 3 (Health through safer pharmaceuticals), 9 (industry innovation), and 12 (responsible production). 2025 Elsevier B.V. -
Nano-architectured polypyrrole based magnetic nanocatalyst for the N- arylation of imidazoles and fused imidazoles
A new magnetically recoverable polypyrrole supported copper based nanocatalyst was synthesized, characterized with various analytical techniques like Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray analysis (EDX), High Resolution Transmission Electron Microscopy (HRTEM), Thermogravimetric analysis (TGA), Vibrating Sample Magnetometry (VSM), and Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. The loading of copper on the surface of the catalyst was found to be 4.23 wt%. The application of the synthesized nanocatalyst was checked for the N-arylation of imidazoles. Excellent catalytic performance was obtained with easy recoverability and reusability upto six cycles. The current green protocol makes it environmentally beneficial for scale-up industries. 2025 Elsevier B.V. -
Mixed CoO/Co3O4 phase nanoparticles encapsulated in a carbon shell derived from Co-MOF as a bifunctional electrocatalyst for scalable hydrogen production
Designing high-performance and long-lasting electrocatalysts is essential to enable large-scale green hydrogen generation through water electrolysis. Herein, we present a bifunctional electrocatalyst, C@CoxOy-B/P-700, obtained by pyrolyzing a Co-MOF under N2 atmosphere, followed by phospho-boronization. Extensive characterization revealed the formation of nanoparticles composed of combined Co3O4 and CoO phases encapsulated by a thin carbon shell. This unique architecture provided electron transport and active site accessibility, while the co-incorporation of boron and phosphorus induced abundant oxygen vacancies, enhancing intrinsic kinetics. In alkaline media, low overpotentials of 220 and 79 mV are required at 10 mA/cm2 for OER and HER, along with excellent durability, maintaining performance over 10,000 cycles and 100 h of continuous operation. When implemented in a symmetric two-electrode configuration, it achieves a current density of 10 mA/cm2 at just ?1.57 V, rivalling noble-metal-based systems. Furthermore, scale-up in a zero-gap alkaline electrolyzer confirms industrial applicability, requiring ?1.72 V to achieve a 500 mA/cm2 at 60 C with a negligible degradation rate. These results emphasize the promise of C@CoxOy-B/P-700 as a sustainable and scalable solution for next-generation hydrogen production. 2025 Elsevier Ltd. -
Cotton-derived carbon fibers and MoS2 hybrids for efficient I3? reduction in bifacial dye-sensitized solar cells
In light of recent advancements, a novel platinum-free counter electrode for dye-sensitized solar cells (DSSCs) has been developed utilizing hierarchical MoS2 structures in conjunction with bio-derived carbon materials. Carbon fibers produced from cotton and molybdenum-doped carbon rods synthesized from melamine were fabricated through a straightforward hydrothermal process, which significantly enhanced both electrocatalytic activity and stability. The resulting counter electrodes exhibited notably low charge transfer resistances of 9.45 ? and 6.43 ?, thus facilitating efficient redox reactions. Consequently, DSSCs incorporating these materials achieved remarkable power conversion efficiencies of 7.04 % and 7.58 %, surpassing traditional platinum-based counter electrodes, which recorded an efficiency of 7.50 %. Furthermore, the high optical transmittance of these materials renders them suitable for bifacial DSSCs, broadening their potential applications. This research underscores the promise of bio-inspired carbon composites as sustainable and efficient alternatives in solar energy technologies, offering an environmentally friendly substitute for conventional noble metal electrodes. 2025 Elsevier Ltd -
Flexible and sustainable dielectric materials from natural rubber and Caryota urens extract for wearable and soft electronic devices
This study explores the structural, mechanical, and dielectric properties of natural rubber (NR) blended with Caryota urens fruit extract (CUFE), with and without glutaraldehyde (GA) crosslinking, for sustainable dielectric materials. CUFE, rich in hydroxyl groups, was incorporated at varying concentrations to improve interfacial polarization and dielectric response. FTIR confirmed successful blending and crosslinking, while SEM revealed enhanced homogeneity with CUFE and GA treatment. Mechanical tests showed improved tensile strength and elongation at break, with optimum performance at 10 wt% CUFE. GA crosslinking enhanced dimensional stability but reduced elasticity due to network formation. Dielectric analysis indicated higher capacitance and lower impedance with increasing CUFE, driven by ionic and interfacial polarization. GA-crosslinked blends exhibited superior dielectric efficiency, with lower energy loss and higher charge storage capability. With flexibility, tunable conductivity, and strong dielectric performance, NR/CUFE blends show promise for flexible capacitors, wearable electronics, sensors, and sustainable devices. 2025 Korean Physical Society -
Arecanut organic residue-enhanced polymer films: An efficient catalyst for amidation reactions
This research introduces an innovative approach to repurpose agricultural by-products as catalysts in chemical synthesis, addressing waste disposal challenges. Composite films were developed using arecanut organic residue, an underexploited by-product, blended with polyvinyl alcohol (PVA) and chitosan. The films were synthesized through solvent casting and thermal curing, with experimental parameters systematically optimized. Physicochemical characterization confirmed successful integration of components and revealed structural properties. The catalytic efficiency of the films was evaluated in amide synthesis, a key reaction in pharmaceuticals. A blend of 1.5 g PVA, 0.3 g chitosan, and 1 mL arecanut residue achieved a 95 % yield in ester-amine reactions, attributed to synergistic interactions between the polymer matrix and reactive sites. The films exhibited excellent reusability, maintaining catalytic efficiency over three cycles. This study highlights the potential of arecanut residue-based composites as sustainable, efficient catalysts for industrially relevant transformations. 2025 Korean Physical Society