Fabrication of Polyamide-Ag2Se composite films with controllable properties by an adsorption-diffusion method

A study of the formation of polyamide (PA)-Ag2Se composites on PA-6 polymer surface through an adsorption-diffusion method and the resulting surface properties is presented. The two-stage process used to deposit these thin layers involved (a) treatment of PA with a precursor K2SeS2O6 solution as a selenium source, and (b) treatment with a solution of AgNO3 as a silver source. The chemical and physical properties of the obtained PA-Ag2Se composites have been investigated by means of AAS, XRD, SEM/EDX, AFM, and sheet resistivity measurements. This study shows that increasing the number of cycles can produce layers with the desired morphology, chemical properties, and phase composition. AAS and EDX analyses have shown that the concentrations of Ag and Se in Ag2Se-PA composite increase with increasing number of cycles. XRD data show crystalline polyamide as a single phase, naumannite Ag2Se as a crystalline phase, and two phases due to monoclinic and rhombohedral Se. The thickness of the composite material layers ranged from several um to about 10.2 mu m, and depended on the number of adsorption-diffusion cycles. It was found that, after five cycles, the sheet resistance of the layers decreased from >20000 to 32 Omega/and then remained constant. SEM and AFM further revealed that Ag2Se does not grow as a uniform film on the polyamide surface, but rather through a nucleation mechanism followed by particle growth, gradually covering the entire polymer surface.