Preparation of poly(acrylic acid)-graphite oxide superabsorbent nanocomposites

Graphite oxide (GO) nanoplatelets with a thickness from 0.8 nm to 2 nm were prepared using a modified Hummers method. By employing GO nanoplatelets as nanofillers, poly(acrylic acid)-GO superabsorbent nanocomposites were synthesized by a facile solution polymerization of acrylic acid monomers using N,N'-methylenebisacrylamide as cross-linker and ammonium persulfate as initiator. The well-dispersed GO nanoplatelets in the polymer networks results in a significant improvement in absorbencies both in distilled water and saline solutions. With only a very low loading of GO in the superabsorbent nanocomposite, for example 0.073 wt%, its water absorbency reaches up to 508 g g(-1), which is nearly as twice that of the poly(acrylic acid) (PAA) superabsorbent. The superabsorbent nanocomposite also exhibits a superior water-retention ability compared with the control under the same conditions. Our study may provide a new way for the development of novel, GO-based superabsorbent nanocomposites with improved absorbency and may find a variety of useful applications.