Problems of diffusion into conductive and modified polymers are concer
ned. Modification, e.g. by ionic implantation, causes chemical changes
in the structure of polymer and, in this way, changes of some of its
chemical properties. The studies of electrical properties of polymers
after successive diffusion from gaseous, liquid and solid phases are s
urveyed. Several examples of doping and changes in electrical conducta
nce of polyacetylene are mentioned.