Preparation of polyethyleneimine-modified chitosan/Ce-UIO-66 composite hydrogel for the adsorption of methyl orange

In this work, a polyethyleneimine-modified chitosan/Ce-UIO-66 composite hydrogel (PEI-CS/Ce-UIO-66) was prepared using the ex-situ blend method. The synthesized composite hydrogel was characterized by SEM, EDS, XRD, FTIR, BET, XPS, and TG techniques, while the zeta potential was recorded for sample analysis. The adsorbent performance was studied by conducting adsorption experiments using methyl orange (MO), which showed that PEI-CS/Ce-UIO-66 exhibited excellent MO adsorption properties (900.5 +/- 19.09 mg/g). The adsorption kinetics of PEI-CS/Ce-UIO-66 could be explained by the pseudo-second-order kinetic model, and its isothermal adsorption followed the Langmuir model. Thermodynamics showed that the adsorption was spon-taneous and exothermic at low temperatures. MO could interact with PEI-CS/Ce-UIO-66 via electrostatic interaction, pi-pi stacking, and hydrogen bonding. The results indicated that the PEI-CS/Ce-UIO-66 composite hydrogel could potentially be used for the adsorption of anionic dyes.

Automated summary

In this study, a polyethyleneimine-modified chitosan/Ce-UIO-66 composite hydrogel (PEI-CS/Ce-UIO-66) was successfully prepared using the ex-situ blend method. The synthesized composite hydrogel was characterized and its adsorption performance for methyl orange (MO) was evaluated. The results showed that PEI-CS/Ce-UIO-66 exhibited excellent adsorption properties for MO through electrostatic interaction, pi-pi stacking, and hydrogen bonding. These findings suggest that the PEI-CS/Ce-UIO-66 composite hydrogel has potential for the adsorption of anionic dyes.