Reduction of copper(II) ions in polyacrylic acid-polyethyleneimine complexes using X-ray radiation

The specifics of X-ray-induced reduction of copper(II) ions in the polyacrylic acid-polyethyleneimine-copper(II) (PAA-PEI-Cu(2+)) complexes were studied. It was found that the action of radiation led to the effective reduction of Cu(2+) in the PAA-PEI-Cu(2+) films swollen in an aqueous-alcohol medium. The formation of metal nanoparticles in irradiated samples was revealed by electron microscopy and X-ray diffraction techniques. Analysis of ESR data has demonstrated that the Cu(2+) reduction rate increases with an increase in the initial concentration of copper ions in the samples. Formal yields of the radiation-chemical reduction of Cu(2+) in the PAA-PEI complex films were found to be quite high (> 100 ions per100 eV of energy absorbed by the swollen film), which can be explained by involvement of the radiolysis products of aqueous alcoholic solutions (outer medium) in the reduction processes.