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Spectroscopic and diffraction studies of chemical deposition of copper sulfide films on polyamide surface using potassium pentathionate

Krylova V.

Materials Science Poland

2007

Vol. 25, No. 4

933--945

Sulfur sorption-diffusion by polyamide PA 6 film exposed to potassium pentathionate K2S5O6 solutions was investigated by the UV, IR absorption spectroscopy and chemical analysis methods. 2 5 6 S O -?anions were found to sorb into the polymer. The study of sulfur sorption-diffusion kinetics showed that the concentration of sorbed pentathionate ions in polyamide film increased with increasing duration of treatment and the temperature of solution. Sulfur concentration in the polymer was found to depend on the conditions of sorption and varied between 0.94 and 7.64 mg/cm3. The estimated apparent diffusion coefficients of 2 5 6 S O -?ions in polyamide increased with increasing temperature of K2S5O6 solution. On treating sulfured polyamide film with copper(I) salt solution, copper sulfide (CuxS) layers are formed in the surface matrix of the polymer. The content of CuxS depended on the concentration of 2 5 6 S O - ions in the polyamide matrix. Initially dielectric, polyamide films after formation of CuxS layers in their surface matrix become electrical conductors. Samples sulfured in K2S5O6 solution at 293 K for 240 min were the most conductive. X-ray diffraction studies of CuxS layers revealed the presence of two phases: chalcosine and djurleite.

Characterization of CuxS Layers Obtained by Adsorption-Diffusion Method on by Adsorption-Diffusion Method on Polycaproamide from K2S5O6 Solutions

Krylova V., Dukstiene N.

Polish Journal of Chemistry

2006

Vol. 80, nr 9

1435-1447

CuxS layers on polycaproamide, obtained by the adsorption-diffusionmethod, have been studied. These layers are formed when the ions of pentathionate (K2S5O6) sorbed into polycaproamide react with a solution of copper(I) salt. By X-ray diffraction studies it was determined that the CuxS layers obtained are of three phases, comprising covellite (CuS), geerite (Cu1.6S), anilite (Cu1.75S) and chalcocite (Cu2S). The concentration ratio of the phases depends on the period of polycaproamide sulfuration in a potassium pentathionate solution. Chalcocite prevails in the composition of CuxS film on PKA. The films were characterized by means of IR spectroscopy. IR absorption spectra were investigated in the region of the wavenumbers 200-1400 cm-1. The characteristic absorption maxima were found in the regions 242-243, 268-290, 339-384, 422-463, 538, 611-612, 879-929, 1018-1095, 1186-1224 cm-1 and assigned, respectively, to delta(S-S-S) and ni (Cu-S), gamma r(SO3), ni(S-S) and ni(Cu-S), delta as(O-S-O), delta s(O-S-O), ni (Cu-S), ni s(S-O) and ni as(S-O). Measurements of electrode potentials in CuSO4 solutions of different concentration have shown that the response time and stability of electrodes in Cu2+ ion solutions depend on the phase composition. Electrodes composed from Cu1.75S and Cu1.6S are not stable in CuSO4 solutions. The response time of a Cu2S electrode depends on concentration change. The change of the potential with an active Cu2+ ion concentration is linear in the range of 1.10-3-4.10-2mol_dm-3, the slope of the linear portion being 31.5mVper decade. The obtained experimental values have been compared with the theoretical values calculated on the basis of thermodynamic data.