Title: A novel pH-responsive material containing residues of glycine and maleic acid as a super adsorbent for the fast removal of dyes and toxic metal ions

Biography:

Ali Shaikh Asrof has completed his PhD from State University of New York at Buffalo and Postdoctoral Studies from Massachusetts Institute, of Technology, USA. He is a Distinguished Professor in the Chemistry Department at King Fahd University of Petroleum & Minerals, Saudi Arabia. He has published more than 220 papers in reputed journals and has been serving as a subject editor in ISI listed Arabian Journal of Science and Engineering. 

Abstract

The alternate cyclopolymerization^1,2 of diallylammonioethanoate [(CH₂=CHCH₂)₂NCH₂CO₂^-] and maleic acid in the presence of a cross-linker 1,1,4,4-tetraallylpiperazinium dichloride followed by treatment with NaOH afforded a novel pH-responsive resin (90% yield) (see the Image). The resin has turned out to be a super-adsorbent for methylene blue (MB) removal with a q_Max of 2101 mg g^-1. The process showed an extraordinarily fast adsorption rate. The presence of the chelating glycine residues was exploited for the removal of Hg(II) ions; the q_Hg(II) was determined to be 263 mg g^-1. The resin also removed MB and Hg(II) simultaneously with remarkable efficacy and was employed to remove pollutants from an industrial wastewater matrix. The resin was exposed to the wastewater after spiking with 0.0 and 10 mg L^-1 each of MB and Hg(II) ions. The concentration of toxic metal ions, especially Hg(II) ions, was reduced to sub-ppb level in the non-spiked sample. For the spiked samples, MB and Hg(II) concentrations are also drastically reduced. Its outstanding performance, better than many a recently reported material, paves the way for its potent application in remedying industrial dye-wastewater. The resin was also found to be extremely efficient in the removal of pararosaniline.HCl as well as Cd(II) ions from aqueous systems. The very impressive performance accorded the resin a prestigious place among many sorbents in recent works.