Interactions between macromolecules and metal nanoparticles in aqueous-saline media

The influence of the concentration of low-molecular-mass salt additives in the reaction medium on the size characteristics of copper nanoparticles in sols formed through the reduction of Cu2+ ions in the presence of a cationic polyelectrolyte and nonionogenic polymers with hydrophilic (poly(ethylene oxide) and hydrophobic (poly(N-vinylpyrrolidone)) main chains has been studied. Formation of sols with a narrow size (diameter) distribution of metal nanoparticle indicates the pseudomatrix character of formation of the metal phase under the studied conditions. Effects of the neutral salt and its concentration in the reaction medium on the synthesis of copper sols and on the mean size of metal nanoparticles are related to a change in the nature or character (when oppositely charged polyelectrolyte macromolecules and copper nanoparticles are involved in interaction) of noncovalent interactions stabilizing the macromolecule-nanoparticle complex on passage from the salt-free aqueous medium to the aqueous-saline medium with a sufficiently high concentration of the neutral salt.