Almantas Danilevicius,^a Stanislovas Grevys,^b Juozas Vidas Grazulevicius,^a* and Violeta Grazuleviciene^c
a Department of Organic Technology, Kaunas University of Technology, Radvilėnu pl. 19, LT-50254 Kaunas, Lithuania,
E-mail: juozas.grazulevicius@ktu.lt
^b Department of General Chemistry, Kaunas University of Technology, Radvilėnu pl. 19, LT-50254 Kaunas, Lithuania
^c Department of Chemistry, Lithuanian University of Agriculture, Studentu g. 11, LT-4324, Akademija, Kauno r. Lithuania

Abstract
The structure of Cu_xS layers, deposited by sorption-diffusion method, on polyethylene (PE) foils was studied. For the preparation of these layers PE samples were treated in the saturated solution thiourea containing an additive such as potassium persulfate in an acid medium. The sulfurized PE samples containing mainly S₆ and S₈ modifications were later treated with the aqueous solution of Cu (I-II) salt containing hydroquinone as a reducing agent. The value of x in the Cu_xS layer formed determined by the X-ray analysis ranged from 1 to 2. These layers contained mainly yarrowite Cu_1.13S, digenite Cu_1.8S and chalcosine Cu₂S. The X-ray diffraction studies showed that the non-stoichiometric Cu_1.13S was formed at the beginning of the formation of Cu_xS layer and its composition approached to Cu₂S, when the duration of sulfured PE interaction with the solution of Cu (I-II) salt increased. The obtained Cu_xS layersof the thickness up to 50 mm showed sheet resistance of ca. 20 W. 

Key words: polyethylene, copper sulfide coatings, diffusion, sorption, sheet resistance