| Abstract: | Native maize starch was grafted by N-acryloyl-N′-cyanoaceto-hydrazide (ACAH) using potassium persulfate as a free radical initiator in aqueous medium. Spectral (FT-IR) and elemental analyses were used in combination to elucidate both the structure and composition of the thoroughly washed grafted samples. Gelation of the produced grafted samples has been carried out in alkaline medium using sodium trimetaphosphate (Na3P3O9) as a cross linker. The effects of temperature and sodium hydroxide, substrate and crosslinker concentrations were found to be significant in determination of the rheological properties of the prepared modified gels. The influence of grafting ratio and cross-linker concentration on the gel swelling ability was investigated in deionized water as well as in sodium and potassium chloride 10?2 molar solutions. The produced gels showed a great tendency towards complexation with many metal cations. Chelation with Cu(II), Ni(II) and Cr(III) chloride solutions has been spectrophotometrically investigated. Stability constants of the formed complexes were found to be of the order of 107. |
