Characterization of polyimide Langmuir-Blodgett films on silver using infrared, Raman and x-ray photoelectron spectroscopies

✍ Scribed by Zhao, W. W.; Boerio, F. J.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 425 KB
• Volume: 26
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199804)26:4<316::aid-sia370>3.0.co;2-5

✦ Synopsis

Ultrathin Ðlms of the dimethylhexadecylamine salt of the polyamic acid of pyromellitic dianhydride (PMDA) and oxydianiline (ODA) were deposited onto silver substrates using the Langmuir-Blodgett (LB) technique. These Ðlms were transformed to PMDA/ODA polyimide by both thermal and chemical processes. ReÑection-absorption infrared spectroscopy (RAIR), surface-enhanced Raman scattering (SERS) and x-ray photoelectron spectroscopy (XPS) indicated that there was no strong interaction between the tertiary amine salt Ðlms and the silver substrates and that imidization of these Ðlms was quite complete. Both RAIR and SERS were also used to determine the molecular orientation in as-deposited tertiary amine salt Ðlms and in Ðlms that were imidized. It was concluded that ODA moieties were parallel to the silver surfaces in the as-deposited Ðlms. However, both SERS and RAIR indicated that imide formation induced orientation in which the PMDA moieties became more perpendicular to the silver surface while the ODA moieties were more parallel.