Functionalized carboxymethyl cellulose/polyethyleneimine nanocomposite with silver nanoparticles for enhanced dye adsorption and antimicrobial properties

The current study demonstrated a novel nanocomposite conducted with carboxymethyl cellulose (CMC)/polyethyleneimine (PEI) hydrogel decorated with silver nanoparticles (Ag-NPs) (CMC/PEI/Ag-NPs) was synthesized to improve the removal efficiency of anionic dyes from aqueous solutions. The resulting CMC/PEI/Ag-NPs nanocomposite was characterized through infrared spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray photoelectron spectroscopy to confirm successful Ag-NPs incorporation with the CMC/PEI/Ag-NPs. The TEM images reveal that the Ag-NPs within the CMC/PEI matrix have an average diameter of approximately 100 nm​. The instrumental analysis confirms the successful synthesis of CMC/PEI/Ag-NPs nanocomposite, highlighting the chemical interaction between CMC, PEI, and Ag-NPs. Batch adsorption experiments assessed the capacity of the composite to adsorb methyl orange (MO) under varying parameters conditions. Under optimal conditions including pH 3, an incubation time of 100 min, a dye concentration of 500 mg/L, and a reaction temperature of 45 °C, the CMC/PEI/Ag-NPs nanocomposite demonstrated outstanding adsorption performance, achieving a maximum adsorption capacity of 286 mg/g. The adsorption process was well described by the Langmuir isotherm and followed a pseudo-second-order kinetic model. The reusability of the CMC/PEI/Ag-NPs nanocomposite was evaluated, and the results demonstrated that after five adsorption–desorption cycles, its adsorption capacity remained at 66 mg/g for MO. These findings confirm its effectiveness and durability for repeated use in the adsorption of anionic dyes. Compared to CMC/PEI, the CMC/PEI/Ag-NPs nanocomposite has excellent and more efficient sterilization efficacy against Escherichia coli (13 ± 0.93 mm), Salmonella typhimurium (11 ± 0.85 mm), Pseudomonas aeruginosa (12 ± 0.55 mm), Staphylococcus aureus (15 ± 1.02 mm), Streptococcus mutans (18 ± 1.14 mm), and Candida albicans (16 ± 1.23 mm). These findings suggest that the CMC/PEI/Ag-NPs nanocomposite holds promise for applications in wastewater treatment, as well as industrial and biomedical fields, providing a sustainable and efficient solution for water purification and microbial control.