Alginate-based Hydrogel Nanocomposites Made by Carbon Nanotubes and Acrylamide/Itaconic acid as Co-monomers

Hydrogel nanocomposites based on alginate polysaccharide were prepared by graft copolymerization of acrylamide and itaconic acid in the presence of carbon nanotube, using methylene bisacrylamide and ammonium persulfate as crosslinker and initiator, respectively. The synthesized samples were characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The effect of carbon nanotube content on some properties of the nanocomposites was investigated. The results showed that with increasing carbon nanotube content, the rate of water absorbency and equilibrium swelling in distilled water decreased whereas in saline solutions the water absorbency increased. Water retention capacity was also studied and the results indicated that the inclusion of carbon nanotube causes an increase in water retention under heating and loud. Furthermore, the possibilities of Cd (II) ion adsorption of samples have been investigated. It was found that incorporation of nanotubes into the hydrogel structure increased the Cd (II) metal ion adsorption capacity of the nanocomposites compared to a free-carbon nanotube sample. It is concluded that the hydrogels can be used as fast-responsive and high capacity sorbents in Cd (II) ion removing processes.