Interaction of H2O, O2 and CO2 with the surface of polyphenylacetylene films: an XPS investigation

✍ Scribed by G. Polzonetti; M.V. Russo; A. Furlani; G. Iucci

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 533 KB
• Volume: 185
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(91)80148-q

✦ Synopsis

The interaction of small molecules (H,O, Or and CO*) with polyphenylacetylene (PPA) thin films has been studied. The airexposed PPA interacts with the atmosphere water vapour, leading to covalently bonded OH groups on the basis of X-ray photoelectron spectroscopy (XPS) core-level spectra of C Is and 0 Is. The surface-depth layer involved in the reaction is about I 5 A, as determined by Ar ion-sputtermg measurements, The ion sputtering allows one also to obtain an oxygen-free PPA surface which m turn is exposed to HZO, O2 and COz. The required gas pressure, in order to reach a detectable interaction, is 2760 Torr. Water vapour undergoes a dissociation reaction which gives OH moieties bonded to the polymer carbon atoms. O2 is only physisorbed at the PPA surface, while CO? gives a chemical reaction which leads to the formation of weakly bonded C=O groups.