Nanocellulose shows potential as an effective natural adsorbent for removing harmful contaminants from wastewater. This paper describes the development of innovative nanocellulose thin films made of cellulose nanocrystals (CNCs), polyacrylic acid (PAA), and active carbon (AC) as adsorbent materials for absorbing azo dyes from wastewater. The CNCs were recovered from sugarcane bagasse using alkali treatment and acid hydrolysis. The composition and processing parameters of the thin films were optimized, and their adsorption capacity was determined using thermodynamic isotherms and adsorption kinetics. Adsorption characteristics such as the methylene blue (MB) dye concentration, contact time, temperature, and pH were investigated to determine how they affected adsorption. The results show that the adsorption process follows pseudo-second-order kinetics. At an adsorbent mass of 50 mg, dye concentration of 50 ppm in 50 mL, and contact period of 120 min at 25 °C, the thin film comprising 64 wt% CNC, 16 wt% PAA, and 20 wt% AC showed high dye removal efficiency (86.3%) and adsorption capacity (43.15 mg/g). The MB removal efficiency increased to 95.56% and the adsorption capacity to 47.78 mg/g when the medium’s pH was gradually increased from neutral to alkaline. The nontoxicity, low production cost, water stability, easy recovery, and high adsorption capacity of these membranes make them suitable for water treatment systems.

In this work, the chemical bath deposition (CBD) technique was utilized in the synthesis of transition metals/GO nanocomposites (Co₃O₄/MnO₂/NiO/GO) for applications in supercapacitor electrodes. The nanocomposites after characterization showed that the electrically conductive nature and wide surface area of graphene oxide (GO) accounted for its incorporation into the nanocomposites. The synergy between the nanocomposites accounts for their improved performance and stable phase. The XRD results revealed cubic, orthorhombic, cubic, and mixed phases for the Co₃O₄/GO (CG), MnO₂/GO (MG), NiO/GO (NG), and Co₃O₄/MnO₂/NiO/GO (CMNG), respectively; their morphologies showed platelet nanoparticles with few agglomerates, with an average particle size of 69 ± 12 nm, 37 ± 09 nm, 58 ± 36 nm, and 36 ± 08 nm, respectively. For the produced materials, electrochemical results revealed maximum specific capacitance values of 2482 F/g from cyclic voltammograms and 1280.48 F/g from the galvanometric test. The results showed that the composites outperform single transition metal oxide (TMO) electrodes, with graphene oxide boosting the electrode performance.

The purpose of this study was to investigate the thermal stability and the decomposition kinetics of ethylene–propylene–diene monomer (EPDM) composite samples loaded with and without lead powder (50, 100, and 200 phr lead) using thermogravimetric analysis (TGA). TGA was carried out at different heating rates (5, 10, 20, and 30 °C/min) under inert conditions in the temperature range of 50–650 °C. Lead addition did not significantly change the onset temperature or peak position corresponding to the maximum decomposition rate of the first derivative of the TGA curve (DTGA) (onset at about 455 °C and T_m at about 475 °C). Peak separation for the DTGA curves indicated that the main decomposition region for EPDM, the host rubber, overlapped the main decomposition region for volatile components. The decomposition activation energy (E_a) and pre-exponent factor (A) were estimated using the Friedman (FM), Kissinger–Akahira–Sunose (KAS), and Flynn–Wall–Ozawa (FWO) iso-conversional methods. Average activation energy values of around 231, 230, and 223 kJ/mol were obtained for the EPDM host composite using the FM, FWO, and KAS methods, respectively. For a sample loaded with 100 phr lead, the average activation energy values obtained via the same three methods were 150, 159, and 155 kJ/mole, respectively. The results obtained from the three methods were compared with results obtained using the Kissinger and Augis–Bennett/Boswell methods, and strong convergence was found among the results of the five methods. A significant change in the entropy of the sample was detected with the addition of lead powder. For the KAS method, the change in entropy, ΔS, was −3.7 for EPDM host rubber and −90 for a sample loaded with 100 phr lead, α = 0.5.

This manuscript optimizes the conjugate heat transfer and thermal-stress analysis for hydromagnetic Brinkman fluid with chemical reaction in permeable media. The governing equations of non-Newtonian Brinkman fluid have been traced out and then fractional derivative approach, namely, Caputo–Fabrizio, is invoked, subject to the exponential boundary conditions. The Fourier Sine and Laplace transforms are applied on governing partial differential equations for generating the analytical results of temperature, concentration and velocity. A comparative study of velocity field is investigated for the sake of long memory and hereditary properties. The analytical investigation of temperature, concentration and velocity field have strong effects on chemical reaction. The graphical depiction of vibrant characteristics of hydromagnetic Brinkman fluid with chemical reaction in permeable media is exhibited for disclosing the sensitivities of different embedded rheological parameters of fluid flow. The results suggested that temperature distribution for smaller and larger Prandtl number has disclosed quick and thicker heat diffusivity.

Nanocomposite (NC) films of polyvinyl alcohol (PVA), lignosulfonate (Lg), and nanosized palladium (Pd) were synthesized by ex-situ casting method. Samples from the synthesized PVA-Lg/Pd NC films were irradiated with 5–100 kGy γ doses. The effect of γ doses on the structural, thermal, and optical characteristics of the NC films were studied using different characterization techniques. The results indicated that the γ irradiation improves the decomposition temperature from 227 to 239 °C, signifying an increase in the thermal stability of the NC films. This was accompanied by a reduction of the melting temperature due to the increase of the amorphous phase. This can be attributed to the dominance of crosslinking. On the other hand, the refractive index increased from 2.21 to 2.32 while increasing the γ dose up to 100 kGy. This was associated with a reduction of the optical bandgap from 3.49 to 3.30 eV, which could be attributed to the increase in the amorphous phase as a result of crosslinking. This indicates an enhancement of the spreading of the NPs inside the blend matrix due to γ irradiation. This results in a more compacted construction of the PVA-Lg/Pd NC films. Furthermore, we used the Commission Internationale de E’Claire (CIE) method to estimate the change in color among the irradiated NC films and the pristine film. The PVA-Lg/Pd NC attained a significant color difference value greater than five, meaning permanent color changes.