Oxidative chemical vapor deposition of polyacenaphthylene, polyacenaphthene, and polyindane via benzoyl peroxide

Abstract

A method is presented to polymerize inexpensive and readily available electron-rich monomers via oxidative chemical vapor deposition. The process uses benzoyl peroxide, an organic oxidant, flash evaporated from a chloroform solution via direct liquid injection. The deposition temperatures ranged from 35°C for indane to 125°C for acenaphthylene and acenaphthene. These temperatures were determined by the volatility and melting point of the monomers, which were vaporized without the addition of a carrier gas. Benzoyl peroxide was not cracked into its respective free radical species but instead used as an oxidant at the substrate temperature. Polyacenaphthylene was deposited as a yellow film indicative of its highly conjugated polymer backbone, whereas polyacenaphthene and polyindane were both transparent dielectrics. Polyacenaphthylene and polyacenaphthene had higher average indices of refraction 1.6819 and 1.6640 (at 632.8nm) than polyindane 1.5690, likely representing their higher density.