MATRIX EFFECTS IN REDUCTION OF NICKEL(II) IN AQUEOUS-SOLUTIONS OF POLYMERS

Nickel(II) was reduced with hydrazine borane or sodium borohydride in aqueous solutions of poly(ethylene glycol), poly(N-vinylpyrrolidone), the copolymer of acrylamide and acrylic acid, and in swollen cross-linked and non-cross-linked copolymers of identical composition. The composites prepared contained both the polymer and minute particles of metallic nickel; these composites gave intense characteristic ferromagnetic resonance signals with a g-factor 2.2 and higher. The size of polymer-metal particles (or of their aggregates), as revealed in electron microscopic examination, was assessed not to exceed 50 nm. According to ferromagnetic resonance studies, the size of nickel particles was less than 10 nm. The particles of nickel in the composites were stable and were not liable to oxidation in water and air.