In this study, new adsorbents were prepared by modifying a montmorillonite clay (Mt) with cethyltrimethyl ammonium bromide (CTAB) to form CTAB-Mt, followed by a second modification process with polyaniline (PAni) to form PAni@CTAB-Mt by in situ polymerization of aniline. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), cyclic voltammetry (CV) and the Brunauer–Emmett–Teller (BET) technique were used to characterize the samples. These adsorbents were used in a batch process to remove methylene blue (MB) from aqueous solution. Factors investigated included initial pH of the solution, contact time and temperature. The adsorption data fit the Freundlich isotherm better than the Langmuir and Temkin isotherms. The maximum adsorption capacities (q_eq) obtained were 108.82 mg·g⁻¹, 71.20 mg·g⁻¹ and 57.36 mg·g⁻¹ for PAni@CTAB-Mt, CTAB-Mt and Mt, respectively. The enhanced adsorption capability of the hybrid material is due to increase in surface area and pore volume of the PAni@CTAB-Mt adsorbent. The adsorption results were found to fit well with the pseudo-second-order kinetics model, with highest correlation coefficient (R²) values of 0.954, 0.942 and 0.958 for Mt, CTAB-Mt and PAni@CTAB-Mt adsorbents, respectively. The pH and temperature had a significant effect on the adsorption process, and the negative values of ΔG suggest that the adsorption process was spontaneous and feasible. The desorption and reusability experiment indicated that PAni@CTAB-Mt has the potential to be a reusable adsorbent for MB removal.

Almond shell-based biocarbon is a cheap adsorbent for the removal of malachite green, which has been investigated in this work. FT-IR, DRX, and BET were used to characterize almond shell-based biocarbon. The nitrogen adsorption-desorption isotherms analysis results showed a surface area of 120.21 m²/g and a type H4 adsorption isotherm. The parameters of initial dye concentration (5–600 mg.L⁻¹), adsorbent mass (0.1–0.6 mg), and temperature (298–373 K) of adsorption were investigated. The experiments showed that the almond shell could be used in a wide concentration and temperature range. The adsorption study was fitted to the Langmuir isotherm and the pseudo-second-order kinetic model. The results of the FT-IR analysis demonstrated strong agreement with the pseudo-second-order chemisorption process description. The maximum adsorption capacity was calculated from the Langmuir isotherm and evaluated to be 166.66 mg.g⁻¹. The positive ∆H (12.19 J.mol⁻¹) indicates that the adsorption process is endothermic. Almond shell was found to be a stable adsorbent. Three different statistical design sets of experiments were taken out to determine the best conditions for the batch adsorption process. The optimal conditions for MG uptake were found to be adsorbent mass (m = 0.1 g), initial dye concentration (C₀ = 600 mg.L⁻¹), and temperature (T = 25 °C). The analysis using the D-optimal design showed that the model obtained was important and significant, with an R² of 0.998.

In this study, a polyaniline-titanium carbide (PANI-TiC) hybrid was synthesized via in situ polymerization to investigate its potential for Congo Red (CR) adsorption. The hybrid was characterized using FTIR, XRD, TGA, TEM, EDS, and UV–vis spectroscopy. The CR adsorption behavior was studied under varying conditions, including contact time (10–100 min), pH (2–12), initial dye concentration (30–300 mg/L), and temperature (273–373 K). Adsorption models, including Langmuir, Freundlich, and Temkin, were evaluated, with the Langmuir model best describing the CR adsorption on PANI-TiC, showing a high correlation coefficient (R ² = 0.997). The adsorption process followed pseudo-second-order kinetics (R ² = 0.998) and was endothermic, as indicated by a positive ∆H of 46.23 kJ/mol. FTIR analysis before and after adsorption revealed interactions between PANI-TiC and CR, which were further explained by a proposed mechanism. Notably, the band gap of the PANI-TiC-CR complex shifted from 2.28 to 2.63 eV, indicating the significant changes in the hybrid's properties upon adsorption.

This numerical study examines heat transfer phenomena, with particular focus on evaluating the cooling performance of embedded cavity technologies for electrical and electronic enclosure applications. The thermo-fluidic characteristics of laminar flow within a confined cavity bounded by isothermal heat sources were analyzed by experimentally measuring thermophysical of premixed binary fluids comprising water and ethylene glycol (EG) at concentrations ranging from 25% to 100%. The Navier-Stokes equations governing this steady-state open system are solved numerically using the finite volume method implemented in the commercial computational fluid dynamics (CFD) software Ansys Fluent v17. This computational approach enables precise determination of convective heat transfer characteristics during the cooling process. Key results are presented in terms of the mixture’s surface-averaged Nusselt number, total Nusselt number, and cooling efficiency within the cavity at various ethylene glycol concentrations (25-100%). Comparative analysis reveals that ethylene glycol coolant exhibits significantly superior cooling performance compared with pure water. This enhancement is demonstrated by progressive increases in both the total Nusselt number (from 11.5 to 14.8, 16.5, 21.8, and 35.9) and in cooling efficiency (from 87.4% to 92%, 95.2%, 97%, and 98.3%), corresponding to ethylene glycol concentrations of 25%, 50%, 75%, and 100%, respectively. Furthermore, enhanced thermo-fluidic behavior is consistently observed with increasing ethylene glycol content.