adsorption of cationic dye from aqueous solutions by green ph responsive hydrogels based on poly(2-acrylamido-2-methyl-1-propanesulfonic acid)

Poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-1-vinylimidazole), hydrogels were synthesized via free radical polymerization reaction at different conditions and modified with di-alkyl halide. p(amps-na+-co-vim)-ag and p(amps-h+-co-vim)-ag were prepared by reducing ag(ch3coo) salts loaded into p(amps-na+-co-vim) and p(amps-h+-co-vim) hydrogels and then reduced by nabh4. metal nanoparticles embedded p(amps-na+-co-vim)-ag and p(amps-h+-co-vim)-ag were visualized by high resolution x-ray photoelectron spectroscopy (hrxps) and transmission electron microscopy (tem). the prepared porous hydrogels and related composites were utilized in the adsorption of rhodamine b from aqueous solutions. among non-quaternized hydrogels, p(amps-na+-co-vim) and its composite outperformed p(amps-h+-co-vim) and p(amps-h+-co-vim)-ag. since high porosity increases absorption capacity, which depends on the size and shape of the pores. in addition, the effect of 1,4-dibromobutane quaternization on the catalytic performance of nano-composites was investigated. finally, the catalyst was easily recovered from the reaction medium and re-used for a further four runs without significant loss of activity. the durability of the catalyst structure without leaching was confirmed by ft-ir spectra and atomic absorption spectroscopy, respectively.