Search Results (171)

This study investigates an innovative hybrid treatment for compost-derived wastewater, combining aluminum-based electrocoagulation (EC), zeolite addition, and magnet assistance. Key experimental variables—presence/absence of magnet, stirring speed (250 and 350 rpm), and contact time (10–30 min)—were systematically varied to analyze process efficiency, electrode dissolution and mass loss, solid–liquid separation dynamics, and quantify energy input and Faraday efficiency (FE). Magnet-assisted processes achieved higher COD reduction at longer treatment times of 30 min and lower mixing speeds of 250 rpm, with up to 89.87%. The highest turbidity reduction of 98.59% is achieved after 20 min at 350 rpm. The magnetic field does not significantly affect the dissolution of Al electrodes, but over time, it helps reduce localized electrode damage, thereby supporting both process efficiency and electrode longevity. Magnetic fields improved sludge settling in shorter treatments by promoting faster aggregation. However, the energy input was generally higher with magnetic assistance. FE in the range of 50.89–65.82% indicates that the actual electrode loss is lower than theoretical. For the experiments conducted according to the L8 Taguchi experimental design, given the significance and contribution of factors to the process, the optimal combination is the absence of a magnet, 350 rpm, and 20 min. Full article

In this study, we couple precise interface engineering via alternating current electrophoretic deposition (AC–EPD) with performance-enhancing structural transformation via annealing, enabling the development of high-performance, stable, and tunable Mn-based cathodes for aqueous zinc-ion batteries (ZIBs). Using AC–EPD to fabricate Mn(BTC) (BTC = 1,3,5-benzenetricarboxylic acid) cathodes followed by thermal annealing to synthesize MOF-derived Mn₃O₄ offers a synergistic approach that addresses several key challenges in aqueous ZIB systems. The Mn₃O₄ cathode prepared via AC–EPD from Mn(BTC) exhibited a remarkable specific capacity of up to 430 mAh/g at a current density of 200 mA/g. Interestingly, the capacity continued to increase progressively with cycling, suggesting dynamic structural or interfacial changes that improved Zn²⁺ transport and utilization over time. Such capacity enhancement behavior during prolonged cycling at elevated rates has not been observed in previously reported Mn₃O₄-based ZIB systems. Kinetic analysis further revealed that the charge storage process is predominantly governed by diffusion-controlled mechanisms. This behavior can be attributed to the intrinsic characteristics of the Mn₃O₄ phase formed from the MOF precursor, where the bulk redox reactions involving Zn²⁺ insertion require ion migration into the electrode interior. Even though the electrode was processed as an ultrathin film with enhanced electrolyte contact, the charge storage remains limited by solid-state ion diffusion rather than fast surface-driven reactions, reinforcing the diffusion-dominant nature of the system. Full article

The controllable transport of droplets on solid surfaces is crucial for many applications, from water harvesting to bio-analysis. Herein, we propose a novel droplet transport controlling method, reconfigurable orbital electrowetting (ROEW) on inclined slippery liquid-infused porous surfaces (SLIPS), which enables controllable transport and dynamic handling of droplets by non-contact reconfiguration of orbital electrodes. The flexible reconfigurability is attributed to the non-contact wettability modulation and reversibly deformable flexible electrodes. ROEW graphically customizes stable wettability pathways by real-time and non-contact printing of charge-orbit patterns on SLIPS to support the continuous transport of droplets. Benefiting from the fast erase-writability of charges and the movability of non-contact electrodes, ROEW enables reconfiguration of the wetting pathways by designing electrode shapes and dynamically switching electrode configurations, achieving controllable transport of various pathways and dynamic handling of droplet sorting and mixing. ROEW provides a new approach for reconfigurable, electrode-free arrays and reusable microfluidics. Full article

As the global energy demand continues to rise, the utilization of lithium-ion capacitors (LICs), which combine the advantages of lithium-ion batteries (LIBs) and electrochemical capacitors (ECs), is also increasing. LICs offer high energy density, high power density, and a long life cycle. However, a prelithiation process is required for graphite-based anode materials. In LICs, the formation of the solid electrolyte interphase (SEI) layer inevitably causes an initial irreversible capacity loss, often resulting in the excessive consumption of lithium ions. Considering the limited lithium resources, prelithiation is essential to achieve a satisfactory electrochemical performance in LICs. Various anode prelithiation techniques have been reported to enhance the capacity of LIBs and LICs. Among these, the direct-contact prelithiation method involves physically contacting lithium metal with the electrode or active material. In this study, direct-contact prelithiation was performed on soft carbon-based anode materials, and LICs were fabricated using activated carbon-based cathode materials. The electrochemical properties of the fabricated LICs were evaluated to demonstrate the feasibility of applying the direct-contact prelithiation technique. Full article

The lack of an in-depth understanding of electrical conduction behaviour in anisotropic carbon fibre-reinforced laminates was reflected by the fact that there was no measurement standard. Various ad hoc experimental techniques were used, involving a range of extrinsic parameters with little or no rigorous control. Not only were widely varying values of electrical conductivity, if not incorrect values, generated, but also the effects of extrinsic parameters were attributed erroneously to those of intrinsic parameters. This predicament was compounded by different techniques used in measurements of volume and surface electrical conduction. This paper formulated the most effective experimental method, using two well-argued solid electrodes, to evaluate electrical conduction with rigorous control of all extrinsic parameters. Its main objectives were to investigate anisotropic volume and surface electrical conduction with a focus on the effects of electrode–specimen contact resistance, clamping pressure, conductive paint, contact face preparations, lay-ups, and specimen dimensions. Unique results and data trends provided the step-changing understanding of electrical conduction, such that the contributions of extrinsic factors were clearly established. The specifical findings showed that (1) the two-probe method was the only viable technique to measure both volume and surface conductivities, (2) all conductivity values were dependent on clamping torques and contact face machining, (3) the conductive paint enhancement effect was an artefact, and (4) obtaining surface conductivities by multiplying volume conductivities with laminate thickness was incorrect. Full article

The development and electrochemical characteristics of ionic liquid crystal elastomers (iLCEs) are described for use as electrolyte components in lithium-ion batteries. The unique combination of elastic and liquid crystal properties in iLCEs grants them robust mechanical attributes and structural ordering. Specifically, the macroscopic alignment of phase-segregated, ordered nanostructures in iLCEs serves as an ion pathway, which can be solidified through photopolymerization to create ion-conductive solid-state polymer lithium batteries (SSPLBs) with high ionic conductivity (1.76 × 10⁻³ S cm⁻¹ at 30 °C), and a high (0.61) transference number. Additionally, the rubbery state ensures good interfacial contact with electrodes that inhibits lithium dendrite formation. Furthermore, in contrast to liquid electrolytes, the iLCE shrinks upon heating, thus preventing any overheating-related explosions. The Li/LiFePO₄ (LFP) cells fabricated using iLCE-based solid electrolytes show excellent cycling stability with a discharge capacity of ~124 mAh g⁻¹ and a coulombic efficiency close to 100%. These results are promising for the practical application of iLCE-based SSPLBs. Full article

A smart capacitive transducer (SCT) for high-frequency vibration (HFV) measurements was developed, featuring self-calibration for the improvement of measurement accuracy. Measurements using this transducer are performed by positioning it over a thin (10 µm) dielectric layer on a conductive surface. This method was shown to be a non-contact vibration measurement technique for solid surfaces at frequencies over 10 kHz. Auto-calibration is performed every time the SCT is placed on the object being measured. This reduces the influence of positioning and the object’s surface properties on the measurement results. For the transducer’s auto-calibration, a predefined vibration of the measurement electrode is induced. This is achieved using a waveguide excited by a piezo element. The diameter of the developed SCT is 5 mm, with a frequency range of 10 kHz to 1 MHz, an object HFV amplitude measurement resolution of several picometers, and a repeatability error of several percent. Full article

This study focused on developing a novel composite phosphate-selective electrode for on-site and real-time applications using a silver polyglutaraldehyde phosphate and carbon nanotube (CNT) matrix. CNT-silver polyglutaraldehyde phosphate compound was synthesized and characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The potentiometric performance of the composite phosphate-selective electrode was then investigated. The results demonstrated that the composite phosphate-selective electrode exhibited good sensitivity, with a linear response in the concentration range of 1.0 × 10⁻⁴ to 1.0 × 10⁻² M for phosphate ions. The electrode also showed high selectivity towards phosphate ions compared to other anions, such as chloride and nitrate. Additionally, the electrode displayed a quick response time of less than 15 s, making it suitable for real-time measurements. The electrode was applied to surface and soil water samples. The results obtained from the water samples showed a strong correlation with those obtained from the preferred spectrophotometry method, highlighting the potential of the developed electrode for on-site and continuous monitoring of phosphate and offering an efficient and practical solution for various fields that require phosphate detection. Full article

Gallium arsenide photoconductive semiconductor switches (GaAs PCSSs) have attracted much attention in pulsed power systems and high-power microwave sources. The quality of ohmic contact has a significant impact on their switching performance. In this article, a 100 nm p-type epitaxial layer and Ti/Pt/Au metal electrodes were introduced into a GaAs PCSS to enhance ohmic contact, resulting in a specific contact resistivity of 3 × 10⁻⁴ Ω·cm². The optimized device exhibited a reduction in dark current from 32.2 μA to 11.7 μA and achieved a peak pulse output of 4 kV under a bias of 8.1 kV. This work provides a new feasible approach for high-power miniaturized solid switches. Full article

Solid polymer electrolytes (SPEs) have attracted much attention due to their excellent flexibility, strong interfacial adhesion, and good processibility. However, the poor interfacial contact between the separate solid polymer electrolytes and electrodes leads to large interfacial impedance and, thus, hinders Li transport. In this work, an ionic liquid-modified comb-like crosslinked network composite solid-state electrolyte with an integrated electrolyte/cathode structure is prepared by in situ ultraviolet (UV) photopolymerization. Combining the enhanced interfacial contact and the introduction of ionic liquid, a continuous and fast Li⁺ transport channel at the electrolyte–cathode interface is established, ultimately enhancing the overall performance of solid-state lithium batteries. The composite solid electrolytes (CSEs) exhibit an ionic conductivity of 0.44 mS cm⁻¹ at 60 °C. LiFePO₄//Li cells deliver a high discharge capacity (154 mAh g⁻¹ at 0.5 C) and cycling stability (with a retention rate of more than 80% at 0.5 C after 200 cycles) at 60 °C. Full article

Indium oxide (In₂O₃) is a promising anode material for next-generation lithium-ion batteries and is prized for its high electrical conductivity, environmental friendliness, and high theoretical capacity. However, its practical application is significantly limited by severe volume expansion and contraction during the lithium insertion/extraction process. This volume change disrupts the solid electrolyte interphase (SEI) and degrades contact with the current collector, undermining battery performance. Although the nano-structured design of In₂O₃ can mitigate the volume effect to some extent, pure In₂O₃ nanomaterials are prone to agglomeration during frequent charging and discharging. The pure In₂O₃-based electrode shows a sustained and rapid capacity degradation. In this study, we embed ultrafine In₂O₃ particles in a carbon nanofiber framework using electrospinning and thermal annealing. The 1D carbon nanofiber structure provides an effective electronic conductive network and reduces the length of lithium-iondiffusion, which enhances the reactivity of the nanocomposite and improves electrode kinetics. Additionally, the carbon nanofiber framework isolates ultrafine In₂O₃ particles, preventing their aggregation. The small volume changes due to the ultrafine size of the In₂O₃ are buffered by the carbon materials, allowing the overall structure of the In₂O₃/C composite nanofiber to remain largely intact without crushing during charging and discharging cycles. This stability helps avoid electrode fracture and excessive SEI growth, resulting in superior cycle and rate performance compared with the pure In₂O₃ nanofiber electrodes. Full article

This paper presents a comparative study on the temperature resistance of solid-contact ion-selective electrodes, depending on the type of solid-contact material. Five types of potassium electrodes, with a valinomycin-based model membrane, were developed using different types of mediation layers, namely a conductive polymer (poly(3-octylthiophene-2,5-diyl) and a perinone polymer), multi-walled carbon nanotubes, copper(II) oxide nanoparticles, and a nanocomposite consisting of multi-walled carbon nanotubes and copper(II) oxide. We examined how the measurement temperature (10 °C, 23 °C, and 36 °C) affects the sensitivity, measurement range, detection limit, selectivity, as well as the stability and reversibility of the electrode potential. Electrodes modified with a nanocomposite (GCE/NC/ISM) and a perinone polymer (GCE/PPer/ISM) showed the best resistance to temperature changes. An almost Nernst response and a stable measurement range and the lowest detection limit values for each temperature were obtained for them. The introduction of mediation layers significantly improved the stability and potential reversibility of all the modified electrodes relative to the unmodified electrode (GCE/ISM). Still, it was the GCE/PPer/ISM and GCE/NC/ISM that stood out from the others, with stability of 0.11 and 0.12 µV/s for 10 °C, 0.05 and 0.08 µV/s for 23 °C, and 0.06 and 0.09 µV/s for 36 °C, respectively. Full article

Monitoring fungicide residues in orange fruits is vital, as fungicides for orange cultivation are increasingly used to prevent yield loss. At the same time, increasing restrictions are added by regulatory organizations. For facile on-site monitoring of the fungicide carbendazim (MBC), five ion-selective potentiometric sensors are proposed and compared. The first two sensors were prepared with a precipitation-based technique using molybdate (sensor 1) and tetraphenylborate (TPB) (sensor 2), respectively. Furthermore, two ionophore-based sensors were prepared using β-cyclodextrin as ionophore together with TPB (sensor 3) and tetrakis(4-chlorophenyl)borate (TpClPB) (sensor 4) as ion-exchanger. Further incorporation of multi-walled carbon nanotubes (MWCNTs) between the graphite rod and the sensing membrane of sensor 4 (sensor 5) further improved the stability and significantly lowered the limit of detection (LOD). Their performance was evaluated according to IUPAC recommendations, revealing linear response in the concentration range 1 × 10⁻⁴–1 × 10⁻² M, 1 × 10⁻⁵–1 × 10⁻² M, 1 × 10⁻⁵–1 × 10⁻³ M, 1 × 10⁻⁶–1 × 10⁻³ M, and 1 × 10⁻⁷–1 × 10⁻³ M with a Nernstian slope of 54.56, 55.48, 56.00, 56.85, and 57.34 mV/decade, respectively. The LOD values for the five sensors were found to be 7.92 × 10⁻⁵, 9.98 × 10⁻⁶, 9.72 × 10⁻⁶, 9.61 × 10⁻⁷, and 9.57 × 10⁻⁸ M, respectively. The developed potentiometric sensors were successfully applied to determine the residue and degradation rate of MBC in orange samples. After the researched fungicide was applied to the orange trees, the preharvest interval (PHI) could be calculated based on the MBC degradation kinetics determined in the tested orange samples. Full article

Soft matter electrolytes could solve the safety problem of widely used liquid electrolytes in Li-ion batteries which are burnable upon heating. Simultaneously, they could solve the problem of poor contact between electrodes and solid electrolytes. However, the ionic conductivity of soft matter electrolytes is relatively low when mechanical properties are relatively good. In the present review, mechanisms of ionic conduction in soft matter electrolytes are discussed in order to achieve higher ionic conductivity with sufficient mechanical properties where soft matter electrolytes are defined as polymer electrolytes and polymeric or inorganic gel electrolytes. They could also be defined by Young’s modulus from about ${10}^5$ Pa to ${10}^9$ Pa. Many soft matter electrolytes exhibit VFT (Vogel–Fulcher–Tammann) type temperature dependence of ionic conductivity. VFT behavior is explained by the free volume model or the configurational entropy model, which is discussed in detail. Mostly, the amorphous phase of polymer is a better ionic conductor compared to the crystalline phase. There are, however, some experimental and theoretical reports that the crystalline phase is a better ionic conductor. Some methods to increase the ionic conductivity of polymer electrolytes are discussed, such as cavitation under tensile deformation and the microporous structure of polymer electrolytes, which could be explained by the conduction mechanism of soft matter electrolytes. Full article

Sprinkle formulations represent an interesting genre of medicinal products. A frequent problem, however, is the need to mask the unpleasant taste of these drug substances. In the present work, we propose the use of a novel sensor array based on solid-state ion-selective electrodes to evaluate the taste-masking efficiency of rosuvastatin (ROS) sprinkle formulations. Eight Multiple Unit Pellet Systems (MUPSs) were analyzed at two different doses (API_50) and (API_10), as well as pure Active Pharmaceutical Ingredient (API) as a bitter standard. Calcium phosphate-based starter pellets were coated with the mixture containing rosuvastatin. Some of them were additionally coated with hydroxypropyl methylcellulose, which was intended to separate the bitter substance and prevent it from coming into contact with the taste buds. The sensor array consisted of 16 prepared sensors with a polymer membrane that had a different selectivity towards rosuvastatin calcium. The main analytical parameters (sensitivity, selectivity, response time, pH dependence of potential, drift of potential, lifetime) of the constructed ion-selective electrodes sensitive for rosuvastatin were determined. The signals from the sensors array recorded during the experiments were processed using Principal Component Analysis (PCA). The results obtained, i.e., the chemical images of the pharmaceutical samples, indicated that the electronic tongue composed of the developed solid-state electrodes provided respective attributes as sensor signals, enabling both of various kinds of ROS pellets to be distinguished and their similarity to ROS bitterness standards to be tested. Full article