Journal of Metastable and Nanocrystalline Materials Vol. 43

Abstract: Herein we report a simple and cost-effective way for synthesis and application of ZnO-PVA nanocomposite using the spin coating technique in which an aqueous solution containing sources of above was deposited on a glass substrate using spin coating technique and further annealed at 120°C. The structural, optical and morphological properties investigated reveals polycrystalline nature of uniformly coated ZnO-PVA composite thin film with a band gap of 3.26 eV. Photo-detector device is made by patterning silver electrodes at two ends of thin film by keeping an electrode gap of ~ 1 mm. Current-voltage measurements are performed under dark and UV illumination. A linear rise in photocurrent under UV illumination (100 μW/cm²) indicate reliable photodetection properties of the device with ~ 6 μA photocurrent, 120 A/W responsivity, 5.8 x 10⁴external quantum efficiency, 6 x 10⁴ sensitivity and 0.6ms rise time, which is highly applicable for fabricating UV photodetectors going to be used for advance application in defence and space.

Abstract: Low-cost and environmentally friendly energy storage is currently being extensively researched, with batteries being one of the primary focuses. However, many battery materials still involve hazardous substances during synthesis and are relatively high-cost. Therefore, this study aims to address these limitations by developing a battery using an alternative material, coalite, synthesized via the Hummer’s method. The primary objective is to investigate the effect of coalite carbonization temperature on the synthesis of reduced graphene oxide (rGO) as a battery cathode. The successful synthesis of rGO was verified through multiple characterization techniques. X-Ray Diffraction (XRD) analysis revealed an amorphous rGO structure with a peak at 25°. Fourier Transform Infrared Spectroscopy (FTIR) identified functional groups such as O-H, C=O, C=C, and C-O, with the presence of C=C bonds indicating the main structural component of rGO. Additionally, Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDS) Mapping showed that the rGO 600 sample exhibited the highest porosity and carbon (C) composition, with a porosity value of 69.19% and a carbon content of 80.26%. Furthermore, the electrochemical performance of the battery was evaluated using Cyclic Voltammetry (CV). The results indicated that as the carbonization temperature increased (rGO 600), the CV curve exhibited a broader quasi-rectangular shape. Based on these findings, the rGO 600 sample derived from coalite exhibits significant potential as a material for sustainable battery development.

Abstract: This study investigated the influence of nanoparticle material type and weight percentage on the flow behaviour of underfill encapsulation in Ball Grid Array (BGA) assemblies. As BGA packages are increasingly used in high-density and high-performance electronic devices, ensuring reliable solder joint encapsulation becomes critical. While nanoparticle-reinforced underfills enhance thermal and mechanical performance, they also introduce complexities in flow behaviour due to changes in viscosity and particle–fluid interactions. To address this, a multiphase numerical model was developed using the Finite Volume Method (FVM) and the Discrete Phase Model (DPM) in ANSYS Fluent to simulate the transient flow of underfill resin reinforced with Al₂O₃, SiO₂, and TiO₂ nanoparticles at varying weight percentages (5%, 10%, 15%, and 20%). The simulation captured the progression of fluid fill at intervals (25%, 50%, 75%, 95%) and measured total flow time. Results revealed Al₂O₃-based underfill consistently achieved faster flow, with the shortest 95% fill time recorded at 69.84 seconds for a 17.16% weight load concentration, while SiO₂-based underfill had the slowest flow, with times exceeding 74 seconds at 20% loading. These differences were attributed to variations in nanoparticle density and dispersion behaviour. A Random Forest regression model trained on simulation data further confirmed that nanoparticle type and concentration were the most significant predictors of flow time. These findings demonstrate that optimal nanoparticle selection can balance mechanical reinforcement with manufacturability. The results offer practical insights for electronics manufacturers aiming to improve process throughput and reliability in advanced packaging by selecting suitable nanoparticle-enhanced underfill formulations.Keywords: Underfill encapsulation, Nanoparticle reinforcement, Finite Volume Method, Discrete Phase Model, Artificial Neural Network.

Abstract: The Rhodamine 6G fluorescent dye, It was dissolved at a concentration in ethanol of 6*10-6 M, was investigated an active laser medium in this work, and its optical and spectral properties were investigated. The fluorescent Rhodamine 6G dye, which was dissolved in ethanol at a concentration 6*10-6 M, was investigated an active laser medium in this work, and its optical and spectral properties were investigated. The chemical reduction process was also used to create gold nanoparticles at concentration of 0.01 M. Three concentrations of gold nanoparticles (2.5, 5, and 7.5%) w/v were added to the Rhodamine 6G dye solution in order to examine how they affected the dye's optical and spectral characteristics. Optical and spectral properties Rhodamine 6G dye sample were analyzed both before to following the addition of gold nanoparticles. After adding gold nanoparticle the dye, the results indicated a shift toward lower wavelengths (red shift) and an increase in optical parameters, with the exception of transmittance. Fluorescence intensity, radiative lifetime, quantum yield, stoke shift, and fluoresce cent lifetime were among the spectrum characteristics. The relative fluorescence intensity dropped after the nanoparticles were applied.

Abstract: This research investigates the photocatalytic degradation of Rhodamine-B (Rh-B) dye using titanium dioxide (TiO₂) nanoparticles. A series of Rh-B solutions with varying concentrations were prepared, and the influence of TiO2 at different weight ratio (3, and 5)% was assessed under ultrasonic treatment. The mention of carbonyl groups might need more explanation, as Rhodamine-B (Rh-B) typically doesn't have strong carbonyl absorption. It may be better to state that the shift in absorbance indicates the degradation or structural changes in Rh-B due to photocatalysis. The results demonstrated that the photocatalytic activity of TiO2 nanoparticles effectively facilitated the degradation of Rh-B, with removal efficiencies improving with increased TiO2 concentration and exposure time to ultrasonic waves. The best result was get on it at the concentration (5%) of added TiO2 nanoparticles, were its represent the high Removal of dyes equal to (71.25%) at the time (20min). Key Word: Rh-B, TiO2, sonocatalysis.

Abstract: Bamboo has emerged as a sustainable and high-performance reinforcement material in composite structures due to its exceptional mechanical properties, rapid renewability, and environmental benefits. Despite increasing use, several challenges—including inconsistent fiber-matrix adhesion, moisture sensitivity, and lack of performance standardization—still limit its full-scale adoption. This article addresses these knowledge gaps by reviewing recent advances in bamboo fiber-reinforced composites (BFRCs), with emphasis on their applications in construction, automotive, aerospace, and biomedical engineering. The advantages of bamboo over synthetic fibers (e.g., glass/carbon fibers) include high specific strength (350 MPa), low density (0.8–1.4 g/cm³), biodegradability, and carbon sequestration potential. Critical processing techniques—such as alkali treatment, compression molding, and 3D printing—are analyzed alongside challenges like fiber-matrix adhesion and moisture absorption. With a growing emphasis on circular economy principles, BFRCs are poised to revolutionize sustainable material design.

Abstract: This study investigates the effect of nano-TiO₂ (nTiO₂) reinforcement on the corrosion behaviour of cold work aluminium composites in a 0.3M H₂SO₄ environment. Al-nTiO₂ composites were fabricated with 0%, 1%, 2%, 3%, and 5% weight fractions of nano-TiO₂ using stir casting. The corrosion performance was evaluated using potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results show that increased TiO₂ content enhances corrosion resistance up to 5%, particularly at lower cold-working loads. Sample J (5% TiO₂, 2 kg load) exhibited the lowest corrosion rate (0.09474 mm/yr) and highest polarization resistance (809.58 Ω). SEM/EDX analysis revealed denser passive layers and reduced sulfur compound deposits in higher TiO₂ composites. This work highlights the effectiveness of nano-TiO₂ in improving electrochemical stability and corrosion morphology of aluminium composites in acidic environments.