Modulation of Viscoelastic and Absorption Properties of Poly(vinyl alcohol)-graphene Oxide Composites

PVA (poly(vinyl alcohol))/GO (graphene oxide) composites were prepared by mixing the PVA aqueous solution and GO aqueous dispersion through the freezing-thawing method. The morphology and chemical structure of GO and composites were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Viscoelastic and swelling properties and absorption capacities of cationic dye methylene blue (MB) were studied as a function of initial concentration of PVA and GO and the number of freezing-thawing cycles. The highest improvement in linear viscoelastic properties of PVA/GO composites was observed with the increase of GO concentration. Experimental data of the kinetic study of MB absorption were well fitted by the pseudo-first-order kinetic model and it was clearly shown that the greatest enhancement of MB absorption was also achieved by increasing the GO concentration. A correlation between swelling, absorption, and viscoelastic and structural properties of PVA/GO composites was proposed.