FILM MATERIALS BASED ON POLYVINYL ALCOHOL, FILLED WITH SILVER NANOPARTICLES

Abstract

In the present work polymeric composite films materials based on polyvinyl alcohol (PVA), glycerol and silver nitrate the conducted composites with high mechanical characteristics were created. In the process of composites drying, glycerol acts as a reducing agent and the formation of silver nanoparticles occurs, moreover the reducing take places at room temperature. The AgNO3 content is varied from 0.01 to 30 wt.%. Taking into account the physical-mechanical and conducting properties of composites, it is established that the optimum content of glycerol in the final material is equal to 30 wt%. The formation of metallic silver was confirmed by an appearance of a surface plasmon resonance band at 420-430 nm in UV spectra and the appearance of two diffraction peaks at 38.17° and 44.15° in X-ray diffraction pattern as well, corresponding to the crystallographic planes (111) and (200) of a face centered cubic lattice of Ag0. Dielectric spectroscopy data show that the increasing of glycerol content up to 30-40 wt.% leads to enhance the conductivity by three orders in comparison with the initial PVA. An increase in the silver content resulted in further rise of the conductivity, reaching value of 5.72 10-6 S/cm at 15 wt.% of silver concentration, at room temperature (20 °C). At 100-120 °С, the conductivity was the highest for the composite with 25 wt.% of AgNO3 - 3.67-3.84 10-4 S/cm. The resulting samples had high physical and mechanical properties: relative elongation of about 400%, tensile strength of 32–36 MPa. Studies of the dynamic light scattering of films solution with Ag NPs showed that the smallest size was for the sample with 0.5 wt.% - 6.3 nm.