Efficient Dye Removal by SA-g-P(AA-co-NIPAM/BENT) Composite Hydrogel

The composite hydrogel sodium graft poly(acrylic acid-co-N-isopropylacrylamide)/bentonite (SA-g-P(AA-co-NIPAM/BENT) emerges as an effective adsorbent to remove methylene blue (MB) and methyl violet (MV) from aqueous solutions through adsorption. Compared with the sodium graft poly(acrylic acid-co-N-isopropylacrylamide) graft copolymer SA-g-P(AA-co-NIPAM), the growth rate in terms of adsorption capacities of MV and MB is 35.5% (from 310 to 420 mg/g) and 10.2% (from 293 to 323 mg/g), respectively, with an incorporation of 0.6 g of BENT. The adsorption of MB on SA-g-P(AA-co-NIPAM/BENT) is spontaneous while MV is nonspontaneous. In addition, adsorption of both dyes satisfies the Freundlich equation and the Pseudo second-order kinetic model.