Chitosan microspheres modified with poly(ethylenimine) enhance the adsorption of methyl orange from aqueous solutions

Abstract

Chitosan (CS) microspheres were prepared by emulsion crosslinking, and the surfaces of the spheres were modified with poly(ethylenimine) (PEI) for preparing efficient adsorbents. Consequently, a series of PEI-modified CS (CS-PEI) microspheres with different ion exchange capacities (IECs) was prepared and used for the adsorption of methyl orange (MO). The adsorption performance of CS-PEI increased significantly with the increase of the sphere IECs, and the maximum adsorption capacity of 400.00 mg/g was achieved at 303 K with CS-PEI-1275, which had the highest IEC in the experiments. The adsorption process of MO well fitted the pseudo-second-order kinetic and Langmuir isotherm models, and the process was favorable at low temperature. Thermodynamic analyses showed that the adsorption of MO by CS-PEI was a spontaneous and exothermic reaction. Furthermore, CS-PEI exhibited good reusability within seven cycles of adsorption-desorption.

Photocatalytic degradation of methyl orange by a diethylenetriamine modified chitosan/bentonite composite

“…Therefore, photocatalytic treatment of MO wastewater by blending chitosan and bentonite could be a feasible method. According to literature reports, 42,43 by modifying the material and introducing corresponding functional groups, the adsorption performance can be enhanced by increasing adsorption sites and chemical stability. Diethylenetriamine contains two primary amine groups and a secondary amine group in its molecules, which provided adsorption sites on the surface of the adsorbent by protonation under acidic conditions that favored electrostatic interaction towards negatively charged pollutants.…”

Polyethylenimine‐modified sugarcane bagasse cellulose as an effective adsorbent for removing Cu(II) from aqueous solution

“…Moreover, the amine group is one of the most effective groups to remove contaminants from wastewater 25 . Thus, polyethylenimine (PEI), a cationic polyelectrolyte containing a large number of amino groups, exhibits strong adsorption ability for heavy metals through complexation or electrostatic interaction 26,27 . The graft of PEI on the surface of adsorbent can provide a large number of amino groups for the adsorption of heavy metals, thus improving the adsorption capacity of the adsorbent.…”

Preparation of aminated chitosan microspheres by one-pot method and their adsorption properties for dye wastewater

“…To improve the adsorption performance, it has been reported that adsorbent material was modified by high chelating coordination of S and N functional groups [18][19][20][21]. However, the reaction steps to achieve polyamine design were numerous in these reports.…”

“…Elwakeel [19] used glutaraldehyde and epichlorohydrine as a medium to bond triethylenetetramine with the chitosan chain through three reactions. Jing et al [20] prepared poly(ethylene imine) aminated chitosan derivatives with the aid of cross-linking agent glutaraldehyde by two reactions. In order to reduce the amount of solvents and reagents used in the multi-step experiment, in this work, aminated chitosan materials were prepared by simultaneous emulsion cross-linking of polyamine reagents.…”