Preparation and characterization of chemically cross-linked zwitterionic copolymer hydrogel for direct dye and toxic trace metal removal from aqueous medium

Abstract

In this work, a zwitterionic copolymer hydrogel with adsorption affinity toward anionic dye and cationic trace metal was prepared by a free radical copolymerization of cationic ([3-(methacryloylamino)propyl] trimethylammonium chloride (MPTC)) and anionic (sodium 4-vinylbenzenesulfonate (SVBS)) monomers. Bis[2-(methacryloyloxy)ethyl] phosphate was used as a cross-linker and its effect on the adsorption properties of the prepared hydrogel was evaluated. The prepared materials were characterized by FTIR, XRD, SEM, EDX, and N2 adsorption at 77 K analysis. FTIR and EDX analysis demonstrated the successful preparation of poly(MPTC-co-VBS). XRD and SEM analysis showed that the poly (MPTC-co-VBS) is amorphous and has quasi-honeycomb morphology with large pores. Increasing the amount of the cross-linker enhanced the adsorption of direct blue 71 dye (DB71) and Pb(II) ions. The highest removal of DB71 and Pb(II) was achieved after 2 h using 1.5 g/L of poly(MPTC-co-VBS); however, the optimum solution pH was 3 for DB71 and 5 for Pb(II). The kinetics and isotherm studies illustrated that the surface of poly(MPTC-co-VBS) is heterogenous with small-sized homogenous pitches and the DB71 and Pb(II) adsorption onto poly(MPTC-co-VBS) is favorable. Finally, poly(MPTC-co-VBS) is more efficient in removing DB71 and Pb(II) from aqueous solutions than many other reported adsorbents.

Controllable Preparation and Research Progress of Photosensitive Antibacterial Complex Hydrogels

“…In the process of preparing hydrogels, covalent bonds are formed between polymer chains through chemical reactions. These reactions cause the polymer chains to be firmly cross-linked together to form a 3D network structure, then the hydrogels are formed [111][112][113]. Table 2 shows the preparation methods, properties, and applications of various photosensitive antibacterial complex hydrogels.…”