Palladium−Polyimide Nanocomposite Membranes: Synthesis and Characterization of Reflective and Electrically Conductive Surface-Metallized Films

Abstract

Palladium-surface-metallized polyimide films were prepared by an unusual macromolecular-matrix-mediated, single-stage synthetic protocol first reported by Taylor et al. (J. Am. Chem. Soc. 1980, 102, 876). Several Pd(II) complexes, [PdCl2(SMe2)2], [PdBr2(SMe2)2], and Pd(CF3COO)2, were dissolved in the poly(amic acid)s of 3,3‘,4,4‘-benzophenonetetracarboxylic acid dianhydride (BTDA)/4,4‘-oxydianiline (4,4‘-ODA) and 3,3‘-diaminobenzophenone (BPDA)/4,4‘-ODA in the solvent dimethylacetamide. Films cast onto glass plates from these Pd(II)-doped resins were thermally cured to 300 °C in air, which resulted in air-side surface-metallized membranes. The films were characterized by both specular and diffuse reflectivity and by conductivity measurements as a function of the cure time and temperature. Maximum specular reflectivities of ca. 50% were observed at 530 nm. After maximum specular reflectivities were achieved in the thermal cure cycle at 300 °C from 0.5 to 2 h, the film surface quickly degraded upon further ...