Cellulose Powder Functionalized with Phenyl Biguanide: Synthesis, Cross-linking, Metal Adsorption, and Molecular Docking

A cellulose polymer functionalized with an amine chelating agent was designed and synthesized in a three-step process that involved oxidizing cellulose powder into dialdehyde cellulose, reacting cellulose dialdehyde with phenyl biguanide to create an imine linkage between the two reactants, and reducing the imine linkage to an amine. The cellulose amine polymer was cross-linked with glycerol digycidyl ether and evaluated as an adsorbent of toxic metal ions from wastewater. The adsorption efficiency of the cross-linked cellulose amine polymer toward Pb(II) and Cu(II) was evaluated as a function of the adsorbent dose, pH, time, temperature, and initial ion concentration. The cross-linked cellulose amine polymer showed an excellent efficiency toward over 15 metal ions present in a real sample of sewage. Thermodynamic analysis showed a spontaneous adsorption of metal ions on the polymer at room temperature. Monte Carlo and Molecular Dynamic simulations showed that the Cu(II) and Pb(II) ions adsorbed onto the cellulose amine polymer surface in a considerable amount, which agreed with the experimental and thermodynamic data. The negative free energy value confirmed the spontaneity of the adsorption process. As such, cross-linked cellulose amine polymers could be a promising alternative to current commercial adsorbents.

Automated summary

A cellulose polymer functionalized with an amine chelating agent was synthesized in a three-step process and evaluated as an adsorbent of toxic metal ions. The cross-linked cellulose amine polymer showed excellent efficiency toward over 15 metal ions present in a real sample of sewage, indicating promising potential as an alternative to current commercial adsorbents. Thermodynamic analysis and simulations confirmed the spontaneity and effectiveness of the metal ion adsorption process on the polymer surface.