X-RAY PHOTOELECTRON-SPECTROSCOPY AND SCANNING ELECTRON-MICROSCOPY CHARACTERIZATION OF NOVEL POLY(MONOSUBSTITUTED) ACETYLENES CONTAINING DOPING SPECIES

The chemical structure of two homogeneously doped polyenes, namely pol y(propargylalcohol) (PPOH) and poly(N,N-dimethylpropargylamine) (Pd-PD MPA), has been investigated by means of x-ray photoelectron spectrosco py (XPS), The study of FeCl3 and I-2 doped PPOH films gave evidence of different chemical states for the dopants into the polymeric chain. T his result confirms that a charge transfer reaction between the polyme r and dopant occurs, as found for analogous systems, An interaction be tween PPOH and the FeCl3 species, involving the metal and the pendant groups of the polymer, is observed. The analysis of HCl doped Pd-PDMPA films shows that the dopant interacts with the polymer by an acid-bas e reaction leading to the protonation of the N atoms. Scanning electro nic microscopy images of the PPOH and Pd-PDMPA pristine films show tha t the final result of the polymerization process is the formation of a flat, enamel-like surface. The chain growth of Pd-PDMPA occurs by a d endrite growth, The enamel-like surface of the PPOH films is maintaine d upon homogeneous doping reaction, whereas a ''craquelet'' effect is observed when the pristine films are exposed to iodine vapors. Homogen eous doping of Pd-PDMPA with HCl exhibits a dramatic modification of t he surface with the appearance of a crystalline structure, due to the acid-base reaction also revealed by the XPS study. (C) 1998 American V acuum Society.