Heavy metal contamination in aquatic environments poses serious risks to human health and ecosystems. Lead, a toxic and potentially carcinogenic metal commonly found in industrial wastewater, can bioaccumulate and damage multiple human organ systems even at low concentrations. This study investigated the use of magnetic biochar derived from iron-containing sludge and spent coffee residues (SCR) via one-step pyrolysis at 700 °C, for the removal of Pb (II) from water. The synthesized biochar was characterized using FE-SEM-EDS, XRD, BET, VSM, and FTIR. Experimental parameters were systematically optimized. Under optimal conditions, the biochar achieved 88.5% Pb(II) ion removal with an adsorption capacity of 22 mg/g from a 20 mg/L Pb(II) solution, and 86% removal with a capacity of 181.5 μg/g from real contaminated groundwater containing 170.3 μg/L Pb(II), within 40 min in batch mode. The adsorption process was analyzed using Langmuir and Freundlich isotherm models. The good fit with both Langmuir and Freundlich models indicates mixed surface characteristics, where monolayer adsorption on homogeneous sites coexists with heterogeneous multilayer adsorption. Kinetic analysis followed the pseudo-second-order model, indicating chemisorption as the dominant mechanism. The synthesized biochar can be regenerated and reused using 0.1 M HNO3 or NaOH, and its adsorption mechanism was proposed. This study demonstrates that the biochar is a cost-effective, sustainable, and efficient adsorbent for toxic heavy metal removal, with magnetic separability supporting its potential for large-scale wastewater treatment.

Gemini-surfactant-coated silver nanoparticles (AgNPs) were prepared employing diester-bonded cationic gemini surfactant (C12-E2O2-C12) as the capping agent. The C12-E2O2-C12-AgNPs were characterized via UV–vis, XRD, FT-IR, HR-TEM, SEM, EDX, DLS, Zeta potential, and XPS analysis. In UV–vis spectra, C12-E2O2-C12-AgNPs exhibited a maximum absorbance of 402 nm. The XRD analysis findings revealed the face-centered cubic (fcc) crystal structure of C12-E2O2-C12-AgNPs. The C12-E2O2-C12-AgNPs exhibited a size of 2–14 nm (∼6.5 ± 2 nm) in HR-TEM analysis. DLS analysis showed the hydrodynamic diameter of 54.48 ± 2 nm with a PDI of 0.486 and a zeta potential of +18.6 ± 5.84. The MIC values of S. aureus-50, Escherichia coli-50, and P. aeruginosa-25 μg/mL presented the eminent antibacterial behavior of C12-E2O2-C12-AgNPs compared to C12-E2O2-C12 and AgNO3. The ground-state complex of BSA with C12-E2O2-C12-AgNPs was formed by electrostatic interaction, with the binding constant of 2.28 × 104 M−1 based on UV–vis analysis. Statistically, the intrinsic fluorescence of BSA was demonstrated by fluorescence spectroscopy, depicting the NPs’ eminent coordinating affinity of the protein’s structural components interaction. Interaction studies of BSA with C12-E2O2-C12-AgNPs proved an excellent binding constant (7.21 × 104 M−1). The FT-IR confirms that the secondary structure of BSA undergoes conformation changes due to C12-E2O2-C12-AgNPs interaction. From circular dichroism (CD) spectroscopy, we observed the α-helical content of BSA decreased from 62% to 46.32% upon its interaction with C12-E2O2-C12-AgNPs. The binding of the prepared C12-E2O2-C12-AgNPs with BSA protein (PDB ID: 3V03) was studied theoretically via molecular docking. The binding energy was estimated to be −10.4 kcal/mol.

To address the instability of nanoparticles (NPs) in base fluids (BF) due to agglomeration and sedimentation, nanofluids (NFs) were developed to enhance heat transfer and thermal system efficiency. Surfactants are commonly added to improve NP stability by inducing steric or electrostatic repulsion to counteract Van der Waals forces. In this study, NFs were prepared by ultrasonically dispersing Al2O3 (0.02–0.5 wt.%) in distilled water, stabilized with Rhamnolipids (RHL, 200–600 ppm) and synthetic surfactants (SDS, SLS, and PVP, 2000–4500 ppm). Stability was assessed using UV-spectroscopy, dynamic light scattering, zeta potential, and viscosity measurements. Results indicated that stability improved with surfactant concentration, peaking at 3750 ppm (SDS), 4250 ppm (SLS), and 550 ppm (RHL). However, stability declined beyond 0.1 wt.% NP concentration, as indicated by a reduction in zeta potential values and UV–Vis absorbance intensity and an increase in particle size, suggesting increased particle aggregation. While RHL showed slightly lower stability than SDS and SLS, it is an eco-friendly alternative. PVP was ineffective and is not recommended for further research. This study is among the first to systematically evaluate the performance of a bio-surfactant, Rhamnolipid, in stabilizing Al2O3 nanofluids and compare it directly with synthetic surfactants.

The present study investigated the formulation and stabilization of Pepper Oleoresin (PO) oil-in-water emulsions using Tween-80 (TW80) and Chitosan (CH) employing ultrasonication. PO emulsions were formulated with various surfactant concentrations (1% to 4% w/w of TW80). The CH concentration varied from 0.005% (CH1) to 1% w/w (CH9) in the PO-TW80 emulsions. The average droplet size, zeta potential, viscosity, density, and morphology were analyzed to understand the emulsion stability. The PO emulsion with 4% w/w TW80 exhibited a homogenous emulsion with nano-sized droplets of around 165 ± 5.9 nm and a zeta potential value of −29 mV. The PO emulsion with TW80 (4% w/w) exhibited good stability (up to 6 months) at room temperature (25 °C ± 2) as the concentration of CH increased (0.005% to 1% w/w). Stable PO emulsions were obtained at 4% w/w TW80 and 1% w/w CH9 with nano-sized droplets around 362.5 ± 18.82 nm and a zeta potential of +45 mV. The interaction between TW80 and CH was confirmed through Isothermal Titration Calorimetry (ITC) and FTIR analysis. In addition, the PO-TW80-CH9 (1% w/w CH) emulsion inhibited the ABTS free radicals (>85%). It also exhibited cytotoxic activity toward MDA-MB-231 cells and displayed antimicrobial effects. The results suggest that the combination of TW80 and CH could serve as an efficient emulsifier system for stabilization of oleoresin emulsions for food and pharmaceutical applications.

This study aims to develop a new approach for removing reactive Yellow X-GL 200% (X-GL) dye from aqueous solutions which involves chemical treatment of forest waste. Citric acid (CA) was utilized to improve the adsorption performance of Brachychiton populneus shells (BS) for textile dye elimination in wastewater. The newly developed CA-modified BPS (CA@BS) was characterized using CHNS elemental analysis, scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, and X-ray diffraction. The adsorption assays were performed to assess the effect of operating factors (e.g., biosorbent mass, adsorption time, pH, X-GL concentration, and temperature) on the X-GL removal performance. A removal efficiency of 96.76% was achieved within 30 min, demonstrating a fast adsorption process. The solution pH had minimal effect, confirming robustness over a wide pH range. Kinetic modeling showed an excellent fit with the pseudo-second-order (PSO) model (R 2 > 0.99). The adsorption equilibrium data were best described by the Langmuir model with a maximum uptake capacity of 400 mg.g−1. Thermodynamic investigation indicated that the X-GL adsorption on the CA@BS is spontaneous (ΔG° < 0) and exothermic (ΔH° < 0). Mechanistic analysis suggested that the X-GL binding mechanism was mainly driven by electrostatic attractions, n–π stacking and hydrogen bonds. Furthermore, the CA@BS biosorbent exhibited high reuse performance up to five adsorption–desorption cycles, confirming its excellent reusability and cost-effectiveness. These findings showed that CA@BS biosorbent is a promising, inexpensive, reusable, and efficient material for removing textile dyes from industrial wastewater.

The objective of this study was to fabricate a chitosan based thermosensitive in situ gel containing riluzole nanosuspension (RLZ-NS) for intranasal drug delivery to the brain. Accordingly, RLZ-NS was produced using anti-solvent crystallization method and optimized based on saturation solubility (Cs), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and dissolution efficiency percentage after 90 minutes (DE90 min%). An I-optimal response surface methodology design was then used to evaluate the impact of the anti-solvent/solvent volume ratio, polymer content and polymer type on these variables. The optimal formulation was then incorporated into a thermosensitive chitosan–β-glycerophosphate hydrogel (RLZ-NS-Hydrogel) and subjected to various evaluations including pH, gelation time, in vitro release, and histopathological tests. The therapeutic efficacy of the optimal RLZ-NS-Hydrogel was tested using the behavioral models of depression in mice. The optimal formulation exhibited a Cs of 683.64 ± 31.14 µg/ml, a PS of 398.70 ± 10.56 nm, a PDI of 0.38 ± 0.01, a ZP of −20.35 ± 2.33 mV, and DE90 min% of 69.23 ± 0.97%. Scanning electron microscopy also revealed that RLZ-NS had a spherical shape. Further, the histopathological effects in sheep nasal mucosa showed that RLZ-NS-Hydrogel had no significant impact on the microscopic structure of mucosa and could be safe for nasal administration. Intranasal administration of RLZ-NS-Hydrogel also produced an antidepressant-like effect comparable to intraperitoneal RLZ in mice, and it was increased, as compared to oral RLZ and intranasal RLZ-Hydrogel. In conclusion, RLZ-NS-Hydrogel showed a potential for nose to brain delivery in treatment of depression.

This research investigates the rheological properties of cement-sand-water slurry utilizing the crude saponin extract derived from Acacia concinna Willd. DC. fruit. The objective of the study was to examine the effects of several rheological factors on the flow behavior of cement-sand-water slurry, including shear rate, yield stress, shear stress, and the correlation between them. Multiple analyses were conducted using a rotational viscometer to determine the effect of crude saponin extract at concentrations ranging from 0.002 to 0.034 g/mL on the viscosity of cement-sand-water slurry with total solid concentrations between 50% to 70% by weight. The flowability of the slurry was also improved by optimizing the cement-to-sand ratio by varying the cement concentration between 10% to 100% in the slurry. The observed rheological results were compared with a commercial surfactant, sodium lignosulfonate. An appropriate mechanistic model was employed to elucidate the interaction between the crude saponin extract, cement, sand, and water. The economic impact of the dispersant has been analyzed by calculating slurry head loss, solids conveying rate, hydraulic power requirements, and specific power consumption, applying the Darby–Melson combined equation at a slurry velocity of 2 m/s with two fixed pipes of diameters 200 mm and 250 mm, nominal bore.

Luliconazole, BCS class II, has been widely used for topical fungal infections. Conventional Luliconazole topical formulation exhibits poor cutaneous absorption and poor drug retention. We hypothesized that Luliconazole microemulsion-based gel with clove/tea tree oil as an oil phase will exhibit synergistic action, improve Luliconazole solubility and cutaneous absorption. The Luliconazole microemulsion containing clove/tea tree oil was optimized by applying a D-optimal design. The independent variables selected were the oil concentration (X1), Smix concentration (X2), and water concentration (X3) while the dependent variables chosen were the globule size (Y1) and flux at one hour (Y2). The globule size and zeta potential optimized Luliconazole Microemulsion were 59/60.4 nm and −1.4/-8.3 Mv for clove/tea tree oil, respectively. The size and sphericity of globules were further confirmed by transmission electron microscopy (TEM) analyses. The optimized clove oil and tea tree oil based LUL ME was further evaluated against Candida albicans (ATCC 10231) and Aspergillus niger (ATCC 16404) utilizing the disk diffusion method. The results of the study indicate a significant increase in the antifungal activity of both microemulsions in comparison to pure drug and higher activity for clove oil microemulsions. The histopathology images of the Wistar rat skin treated with optimized LCZ microemulsion gel further confirmed that neither of the formulations caused any disturbances to the skin’s epithelial layer. The findings of this study were encouraging for the pharmaceutical industry because it offers a complementary treatment for topical fungal infection.

Polyester is a widely used thermoplastic polymer known for its versatility in various fields. Despite its favorable properties like easy processing and good mechanical strength, its poor flame-retardant capabilities and sensitivity to UV light limit its applications. In this study, a novel and sustainable approach was adopted to functionalize lignin nanoparticles (LNPs) for polyester coating to develop textiles with multifunctional properties. The synthesized LNPs coatings were characterized using SEM, DLS, FTIR, and 1HNMR techniques. In a typical procedure, LNPs assembled in water, with a narrow size distribution of 184.70 ± 6.50, were prepared and then coated to the polyester fabric surface through dipping & coating approach. This coating significantly enhanced flame retardancy, antioxidant activity, thermal stability, and UV resistance of the fabrics. Compared to untreated PES, LNPs-coated fabric showed a 42% reduction in peak heat release rate during microscale combustion testing and improved mechanical properties. Thus, the development of such functional textiles fabrics with plant-derived materials will be fruitful in the future in terms of sustainability for desired applications.

This work was designed to explore the adsorptive potential of activated carbon prepared using pineapple waste biomass in removing 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous medium. The pineapple waste biomass was functionalized using 0.3 M ortho-phosphoric acid (H3PO4) and then carbonized in an oven at 250 °C for 8 h. The carbonized pineapple waste biomass (PWB) was washed with distilled water to neutrality (pH 7), followed by oven drying to form activated pineapple waste biomass (APWB). The prepared activated carbon was characterized using several methods including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Transmision Electron Microscopy (TEM) and pH point of zero charge (pHpzc), respectively. The adsorptive potential of APWB in the removal of 2,4-D was investigated via the batch adsorption process. Operational parameters including agitation time, solution temperature, and initial concentration were examined. Isotherm, kinetics, and thermodynamics studies were also evaluated. Prominent functional groups such as O-H, COOH, C-O, C=C, C-H, with a well-developed pores and a high carbon content (79.76%) are present on the surface of APWB. The pHpzc of 3.5 was recorded for APWB. Langmuir isotherm and the pseudo-second-order kinetics model best represent the adsorption process. A maximum adsorption monolayer coverage of 109.63 ± 2.9855 mg/g was obtained for the adsorption of 2,4-D onto APWB. It was revealed that the adsorption process was favorable, spontaneous, and exothermic based on the thermodynamic study. In conclusion, the activated carbon prepared from PWB was efficient in the uptake of 2,4-D from aqueous medium. The findings in this study will be of immense use to water treatment experts.