Mechanically strong graphene oxide/sodium alginate/polyacrylamide nanocomposite hydrogel with improved dye adsorption capacity

In this paper, a novel graphene oxide (GO)/sodium alginate (SA)/polyacrylamide (PAM) ternary nanocomposite hydrogel with excellent mechanical performance has been fabricated through free-radical polymerization of acrylamide (AAm) and SA in the presence of GO in an aqueous system followed with ionically crosslinking of calcium ions. As-prepared GO/SA/PAM (weight ratio SA : AAm = 1 : 2) ternary nanocomposite hydrogel with 5 wt% of GO displays a compressive stress as high as 1.543 MPa at the compressive deformation of 70%. The tensile strength and modulus of the hydrogel achieved ∼201.7 and ∼30.8 kPa, respectively. In the meantime, the ternary nanocomposite hydrogels can recover a large proportion of elongation at breakage and exhibits good elasticity. Additionally, the GO/SA/PAM ternary nanocomposite hydrogel exhibited good adsorption properties for water-soluble dyes. After introducing GO, the dye adsorption capacities of the hydrogel were significantly improved.