Supercapacitors improved electrochemical characteristics, especially their high specific capacitance, rapid charge-discharge capability, and long cycling life. Positioned between batteries and conventional capacitors, supercapacitors offer an intermediate solution with relation to power density and energy. In this work, a NiV-LDH@NiCo-MOF composite was synthesized using a hydrothermal method and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, and scanning electron microscopy (SEM). Metal-organic frameworks (MOFs) are crystalline porous materials made up of metal ions or clusters linked together by organic molecules. They possess tunable porosity, redox-active, and high surface areas, are appropriate for use as sacrificial templates or functional linkers. But, their utilization in energy storage is constrained by extensive poor conductivity, diffusion routes, and few exposed active sites. However, their practical use is often limited by poor electrical conductivity, long ion-diffusion pathways, and insufficient exposure of active sites. To overcome these limitations, hybrid architecture was constructed through the direct growth and interconnection of MOF nanoparticles and layered double hydroxide (LDH) nanosheets, resulting in a robust structure in which the LDH nanosheets are firmly anchored to the MOF framework. The composite NiV-LDH@NiCo-MOF showed an impressive specific capacitance of 1424 Fg - 1 at a current density of 1 Ag - 1.
Sweat contains a rich repertoire of biomarkers that can reflect physiological health statuses, such as electrolyte imbalance, stress levels, and certain diseases. This makes it an ideal biofluid for continuous, noninvasive monitoring via miniaturized wearable electrochemical biosensors. Herein, we developed a wearable sweat pH-sensing patch. The patch incorporates a polyaniline (PANI)-based pH-sensing electrode fabricated via screen-printing technology, which features a high specific surface area, enabling the simultaneous and real-time monitoring of sweat pH. The as-fabricated pH sensing patch demonstrates a high sensitivity of 45.8 mV & centerdot;pH-1, a good linear response (R 2 = 0.9732), excellent cycling stability, a rapid response time (20 s), and a broad detection range (pH 3 similar to 8). Furthermore, when integrated with a self-developed miniaturized acquisition system, the patch successfully captured the dynamic variations in sweat pH during human physical exercise, thereby validating its stability and reliability in real-world scenarios. This work provides an effective wearable solution for personalized health monitoring and scientific exercise assessment, showcasing considerable application potential.
Paraffin wax is inexpensive and readily processed but intrinsically insulating. This study aimed to quantify how polyethylene (PE) and chemically reduced nominal silver nanoparticles (AgNPs) affect apparent room-temperature electrical conductivity and to determine whether ternary wax/PE/AgNP formulations consistently outperform matched wax/AgNP controls. Three independent composition series were prepared: wax/AgNP (5 g wax; 0.1-1.0 g AgNP), wax/PE (5 g wax; 5-15 g PE), and wax/PE/AgNP (5 g wax; 5-23 g PE and 0.2-2.0 g AgNP increased together). Silver powder was prepared by citrate-assisted precipitation and chemical reduction. PE-containing formulations were hot blended at 100-110 degrees C; AgNPs were added at approximately 40 degrees C, followed by 3 h of stirring. Electrical response was measured at approximately 25 degrees C using a four-terminal configuration. Conductivity increased from 0.025 to 0.499 & micro;S/cm in the wax/AgNP series, from 0.0114 to 0.170 & micro;S/cm in the wax/PE series, and from 0.081 to 4.20 & micro;S/cm in the ternary series. The ternary endpoint corresponds to 4.20 & times; 10-4 S/m. Because PE and AgNP mass co-varied in the ternary series, their independent contributions could not be separated. At matched AgNP masses, the ternary formulation exceeded the binary control only at 0.2 g AgNP. The matched-control analysis therefore supports a composition-dependent increase but not synergy, a percolation threshold, or a verified dispersion mechanism.
Under conventional spin-coating conditions, poly(vinylidene fluoride) (PVDF) films are difficult to crystallize into the highly electroactive beta-phase, while direct blending of polyaniline (PANI) often causes aggregation and structural defects. Here, we replace the bulk PANI dispersion with its supernatant to suppress macroscopic aggregation while retaining the ability to regulate the electroactive phase structure. A systematic concentration-dependent study reveals progressive phase evolution from alpha-dominant at low concentration, to gamma-dominant (96.3% at 25 mg/mL), and ultimately toward increased beta-phase content (29.6% at 100 mg/mL). Notably, the PANI supernatant induces these phase changes without introducing micron-scale aggregates or macroscopic phase separation within the examined SEM fields of view, preserving film continuity. These results demonstrate that the supernatant approach enables effective phase regulation with minimal particle aggregation, providing a straightforward and scalable strategy for tailoring PVDF films in flexible electronics.
High-density polyethylene (HDPE) is extensively employed owing to its affordability, chemical resistance, and ease of manufacturing; however, its relatively limited mechanical and thermal properties restrict its use in advanced structural applications. In this study, HDPE was reinforced with reduced graphene oxide (rGO) to develop lightweight nanocomposites with improved multifunctional properties. HDPE/rGO nanocomposites containing 0.25, 0.5, 0.75, and 1 wt.% rGO were fabricated via twin-screw melt compounding followed by injection molding. The influence of rGO loading on thermal, mechanical, structural, and morphological behavior was systematically investigated. Tensile results revealed a maximum strength improvement of 34.4% at 0.25 wt.% rGO, while enhanced ductility was observed at 0.75 wt.% rGO. Differential scanning calorimetry indicated a progressive increase in melting temperature, indicating that rGO influences the melting behavior of HDPE. Thermogravimetric analysis demonstrated improved thermal stability due to the barrier effect of rGO nanosheets. SEM observations suggest a relatively uniform dispersion of rGO nanosheets together with good interfacial interactions at optimal loadings. Overall, the results demonstrate that the optimum filler content depends on the property of interest, with 0.25 wt.% maximizing tensile strength and 0.75 wt.% improving ductility, demonstrating the potential of HDPE/rGO nanocomposites for lightweight structural and engineering applications.
