Nanofluids as heat transfer fluids have been acquiring popularity ever since their beginning. Therefore, the refrigeration research could not keep itself away from the ever-rising horizon of nanofluid applications. On the other hand, nanofluid stability remains the critical bottleneck for use. A significant reduction in nanofluids’ performance can derivate from instability phenomena. Looking to industrial applications, nanofluid long-term stability and reusability are crucial requisites. Nanoparticles’ deposits induce microchannel circuit obstruction, limiting the proper functioning of the device and negating the beneficial characteristics of the nanofluid. The aggregation and sedimentation of the particles may also determine the increased viscosity and pumping cost, and reduced thermal properties. So, there is a need to address the features of nanofluid starting from realization, evaluation, stabilization methods, and operational aspects. In this review, investigations of nanorefrigerants are summarized. In particular, a description of the preparation procedures of nanofluids was reported, followed by a deep elucidation of the mechanism of nanofluid destabilization and sedimentation, and finally, the literature results in this field were reviewed.

Nowadays, iron (II) selenide (FeSe), which has been widely studied for years to unveil the high-temperature superconductivity in iron-based superconductors, is drawing increasing attention in the electrical energy storage (EES) field as a supercapacitor electrode because of its many advantages. In this study, very small FeSe particles were synthesized via a simple, low-cost, easily scalable, and reproducible solvothermal method. The FeSe particles were characterized using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS), revealing enhanced electrochemical properties: a high capacitance of 280 F/g at 0.5 A/g, a rather high energy density of 39 Wh/kg and a corresponding power density of 306 W/kg at 0.5 A/g, an extremely high cycling stability (capacitance retention of 92% after 30,000 cycles at 1 A/g), and a rather low equivalent series resistance (R_ESR) of ~2 Ω.

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for additive manufacturing. The composite was extruded into filaments and printed into circular disc electrodes using fused deposition modeling (FDM). These electrodes were assembled into symmetric supercapacitor devices with a solid-state electrolyte. Electrochemical characterization, including cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests, demonstrated considerable mass-specific capacitance values of 136.2 F/g and 133 F/g at 20 mV/s and 1 A/g, respectively. The devices showed excellent stability, retaining 91% of their initial capacitance after 5000 cycles. The incorporation of silver nanoparticles enhanced the conductivity of rGO, while PANI-DBSA improved electrochemical stability and performance. This study highlights the potential of combining advanced materials with 3D printing to optimize energy storage devices, offering a significant advancement over traditional manufacturing methods.

Glucose detection is critical in addressing health and medical issues related to irregular blood levels. Colorimetry, a simple, cost-effective, and visually straightforward method, is often employed. Traditional enzymatic detection methods face drawbacks such as high costs, limited stability, and operational challenges. To overcome these, enzyme mimics or artificial nano-enzymes based on inorganic nanomaterials have garnered attention, but their cost and susceptibility to inactivation limit applications. This study presents a ZnFe₂O₄/GQDs nanocomposite as an innovative enzyme mimic, addressing key requirements like low cost, high stability, biocompatibility, and wide operational range. Synthesized using a simple and inexpensive method, the composite benefits from the synergistic interaction between ZnFe₂O₄ nanoparticles and graphene quantum dots (GQDs), resulting in excellent magnetic properties, high surface area, and functional versatility. The material demonstrated remarkable sensitivity with a detection limit of 7.0 μM across a range of 5–500 μM and achieved efficient peroxidase-like activity with Km values of 0.072 and 0.068 mM and Vmax of 4.58 × 10⁻⁸ and 8.29 × 10⁻⁸ M/s for TMB and H₂O₂, respectively. The nanocomposite also exhibited robust recyclability, retaining performance over six reuse cycles.