Superabsorbent amphoteric nanohydrogels: Synthesis, characterization and dyes adsorption studies

The goal of the present research is to remove high percentage of cationic and anionic dyes such as, Neutral Red, Safranin O and Indigo Carmine from aqueous solutions by poly(NIPAAm/N,N-diallylpyrrolidinium bromide/AA) superabsorbent amphoteric nanohydrogels synthesized using the inverse microemulsion polymerization method. Effect of various parameters such as, treatment time, initial dye concentration, pH and adsorbent dose were investigated. Furthermore, kinetics and isotherms adsorption models were applied to determine the maximum adsorption and mechanism for adsorption, which shows that adsorption obeyed the pseudo-second order kinetics. From the results, removal of dyes within the nanohydrogel was found to be in the order: AB-74 < BR-2 ≤ BR-5.

Poly(NIPAAm/DAPB/AA) superabsorbent amphoteric nanohydrogels have been synthesized by the inverse microemulsion polymerization method. Due to their amphoteric nature, they are able to remove high percentage of cationic and anionic dyes such as, Neutral Red, Safranin O and Indigo Carmine from aqueous solutions. Based on a removal study, the maximum removal efficiency of the nanohydrogel was found to be 94.48% BR-5 in 300 ppm, 91.71% BR-2 in 300 ppm and 69.30% AB-74 in 200 ppm.Figure optionsDownload as PowerPoint slide