Graphene oxide/poly(acrylic acid) hydrogel by γ-ray pre-irradiation on graphene oxide surface

Graphene oxide/poly(acrylic acid) (GO/PAA) hybrid hydrogel was prepared using a gamma-ray pre-irradiation technique. The functional groups in graphene oxide were modified to peroxide in an O-2 environment with gamma-ray radiation. Radical species from the thermal decomposition of peroxides initiated radical polymerization of the acrylic acid monomers. Modified GO and GO/PAA hydrogels were investigated using scanning electron microscopy and Fourier transform infrared (FTIR), Raman, and electron spin resonance spectroscopy. The thermal, mechanical, and swelling properties of GO/PAA hydrogel were studied by a tensile stress-strain curve and thermal gravimetric analysis. A genuine binary hybrid hydrogel of graphene oxide and PAA was obtained from a simple synthetic procedure based on gamma-ray pre-irradiation without further additives.