Polyelectrolyte multilayer films as reactors for synthesis of silver/polymer nanocomposites.

摘要

Multilayer films formed by the sequential adsorption of polyelectrolytes from aqueous solution were used in the research for this thesis as reactors for the in situ growth of silver nanoparticles. When films consisting of poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) or PAA and poly(ethyleneimine) (PEI) are immersed in AgNO3(aq) solution, PAA carboxylic acid (COOH) groups within the film bind silver cations by ion exchange with acid protons. PEI is furthermore appealing because it contains amine groups that can form complexes with metal ions. Ag +-containing films were photochemically reduced to yield Ag/polymer nanocomposites. The number of available binding groups is strongly dependent on multilayer processing conditions. Using a combination of UV-Visible spectroscopy and transmission electron microscopy, optimal assembly conditions (chemical structure of polyelectrolytes, multilayer assembly pH, AgNO3(aq) concentration and exchange time) for generating films with high Ag content for potential application as conductive films, were explored.