Grafting of N-vinyl-2-pyrrolidone onto κ-carrageenan for silver nanoparticles synthesis

A water soluble, non-gel, poly (N-vinyl-2-pyrrolidone)/κ-carrageenan (PVP/KC) hybrid was synthesized by graft copolymerization of N-vinylpyrrolidone (VP) onto κ-carrageenan in an aqueous medium using ammonium persulphate (APS) as an initiator. Factors affecting the polymerization reaction such as ammonium persulfate concentration, reaction temperature and time, liquor to KC ratio (LR) and KC to VP molar ratio were studied. The results obtained revealed that the optimum reaction polymerization conditions to prepare that hybrid with a total conversion of 93.9% are: [VP], 0.1799 mol/L; VP/KC molar ratio, 50%; [APS], 0.0105 mol/l; LR, 15 l/k; reaction temperature, 90 °C and reaction time, 75 min. Moreover, the grafted KC of that hybrid was characterized via investigating its FTIR analysis. Furthermore, the potential application of such hybrid as a route for synthesis of silver nanoparticles (Ag NPs) using AgNO3 as a precursor was investigated. The synthesized Ag NPs are characterized using the ultraviolet-visible spectroscopy (UV-vis) as well as transmission electron microscope (TEM). The UV-vis showed a band at 435 nm that confirms the presence of Ag NPs. The TEM image shows that such nanoparticles have a spherical structure with an average size ranging from 3 −18 nm.