Graphene/polyacrylamide interpenetrating structure hydrogels for wastewater treatment

Abstract

Abstract Acrylamide (AM) was used as the initial reaction monomer, N,N-methylene bisacrylamide (MBA) was used as the crosslinking agent, and ammonium persulfate (APS) was used as the initiator to prepare the first network structure. Graphene oxide (GO) aqueous solution was dispersed after heating and reacted with tannic acid (TA) to generate the interpenetrating network structure (IPN). The hydrogel composite was characterized by the Fourier transform infrared, ultraviolet spectrum techniques and scanning electron microscopy to analyze structural characteristics and adsorption interactions. Thermodynamic investigation explored the nature that adding GO into the hydrogel, the thermogravimetric temperature increases with the amount of GO. The reaction kinetics was essentially consistent with the pseudo-second-order model with rate dominated by the intraparticle diffusion model as well as the film diffusion mechanism. The water absorption in the equilibrium state was about 300%, better sorption capacity (110.25 mg/g for nickel chloride).