Novel Phase of Elemental Silver Nanoparticles Formed by the Combination of complexing and redox processes into Gelatin Matrix

摘要

The process of "reprecipitation" of elemental silver according to scheme Ag→Ag4[Fe(CN)_6]→Ag into gelatin-immobilized matrices, on the first stage of which these matrices are processed with water-alkaline solutions containing potassium hexacyanoferrate(Ⅱ) and potassium hexacyanoferrate(Ⅲ), on the second stage, with water-alkaline solutions containing tin(Ⅱ) dichloride and organic or inorganic substance forming rather stable soluble coordination compounds with Ag(Ⅰ). D = f(D~(Ag)) and D = f(C_(Ag)~v dependences where D is an optical density of "re-precipitated" silver in the matrix corresponding to initial density D~(Ag) and volume concentrations of elemental silver C_(Ag)~v. It has been found that a degree of influence of complex-formed substance (D/D~(Ag)) is determined with its nature as well as its concentration in reducting solution; besides, the most considerable this influence is in the case of ethanediamine-1,2, the least considerable one, in the case of ammonia. It has been found that silver formed in gelatin matrix, contains two various phases distinguished between themselves by optical and XRD parameters; in addition, one of these phases consists of nano-particles of elemental silver.