Formation of Copper Sulfide–Copper Telluride Layers on the Polyamide Film Surface, Using Sodium Telluropentathionate

Abstract

The layers of copper chalcogenides – mixed copper sulfide–copper telluride, CuxS-CuyTe, were formed on the surface of
semihydrophilic polymer – polyamide 6 using (0.01 – 0.10) mol/dm3 solution of sodium telluropentathionate,
Na2TeS4O6, in 0.2 mol/dm3 HCl as precursor of chalcogens. The concentration of sorbed tellurium and sulfur increased
with the increase of the duration of treatment and concentration of Na2TeS4O6 solution. The mixed copper sulfidecopper
telluride, CuxS-CuyTe, layers were formed on the surface of polyamide 6 after the treatment of chalcogenized
polymer with Cu(II/I) salt solution (10 min, 78 °C): the anions TeS4O6
2– containing tellurium and sulfur atoms of low
oxidation state react with the copper(II/I) ions. The conditions of a polymer initial chalcogenation determine the
concentration of copper and composition of the chalcogenide layer. The concentration of copper in the chalcogenide
layer increases with the increase of initial chalcogenization duration and the concentration of solution. The results of
XRD confirmed the formation of mixed copper sulfide-copper telluride layers on the surface of polyamide 6: four
copper sulfide phases, digenite, Cu1.8S, djurleite, Cu1.9375S, anilite, Cu7S4, geerite, Cu1,6S, four copper telluride phases –
tetragonal Cu3.18Te2, Cu2.72Te2, hexagonal Cu2Te, and orthorhombic vulcanite, CuTe, were identified in the layers. At
room temperature, electrical sheet resistance of the layers varied from ~ 2.0 kΩ/ to 1.2·103 kΩ/. Variation in the
resistance of layers on the surface of PA shows an evident decrease with the increasing of the mass fraction of tellurium.
The data determined enable formation of the layers of copper sulfide-copper telluride on the surface of PA of desirable
conductivity by the sorption method using the solutions of sodium telluropentathionate as a precursor.