Graphene oxide/poly(vinyl alcohol) hydrogels with good tensile properties and reusable adsorption properties

Graphene oxide (GO)/poly(vinyl alcohol) (PVA) hydrogel (PGOH), which possesses good tensile and reusable absorption properties, has been prepared by the freezing-thawing method. The presence of GO visibly decreases the swelling ratio of PGOH and significantly enhances the tensile properties of PGOH due to the formation of hydrogen bonds between the GO and PVA. The maximum tensile strength and the equilibrium adsorption capacity of methylene blue (MB) of PGOH with 0.5wt-% GO (PGOH-0.5) is found to be 15, being 4.1 times higher than that of pure PVA hydrogel. The spontaneous adsorption obeys the intraparticle diffusion kinetic model. In addition, PGOH-0.5 exhibits a promising cycling absorption performance. The 1st and 5th cycle of dye removal for PGOH-0.5 reached to 92 and 70%, respectively. Such enhancement in adsorption can be attributed to - stacking and strong electrostatic attraction between GO and MB.