Multilayer coatings based on polyimide track membranes and nanodispersed lead

Abstract

Multilayer coatings are obtained by “bonding” several layers of polyimide track membranes filled with metallic lead. The bonding of the layers is carried out by an imidization reaction, specifically, the production of polyimide from polyamic acid at 250–270 °C and a pressure of 200 MPa for 30 min. To fill the pores with nanodispersed lead, we use galvanic deposition of metallic lead through the etched channels of the polyimide track membranes. This study presents data on the electrodeposition of nanodispersed lead, including the formation of a cathode coating, the electrolyte used and the optimal electrolysis conditions. Potentiostatic curves obtained during electrodeposition of lead into pores with a diameter of 200 nm at various fixed potentials (−200, −400 and −600 mV) are presented. It is established that as a result of electrodeposition, the channels are completely filled, as evidenced by the formation of lead nanowires. According to the results of X-ray diffraction, the nanowires are metallic lead with a pronounced cubic crystal structure of Fm3m, with no additional peaks detected. The diffraction peaks of lead nanowires are slightly wider compared to bulk lead. The resulting multilayer coating with a thickness of 300 μm has high physicomechanical and dielectric properties with a tensile strength of 76 MPa, an elongation in tension of 10.2% and a specific volume resistivity of 103 Ω m.