A Mechanistic Study of the Plasma Polymerization of Ethanol

Plasma polymer thin films are useful in a variety of different fields. In this article, the fragmentation of ethanol during plasma polymerization at different discharge powers (2-32 W) is described. The positive ion mass spectrometry data of the plasma phase demonstrated formation of oligomeric species of the type [M+H]⁺, [2M+H]⁺, [3M+H]⁺, and [4M+H]⁺. At the same time, there was abundant fragmented species most dominant being ethylene C₂H₄, acetylene C ₂H₂, water H₂O, and hydrogen H₂. X-ray photoelectron spectroscopy was used to relate the mass spectroscopy data of the plasma to the chemistry of the deposited films. Depletion of oxygen in the deposit correlated with greater fragmentation in the plasma phase at higher plasma power. This paper reveals the fragmentation of ethanol during plasma polymerization at different discharge powers. The positive ion mass spectrometry data of the plasma phase demonstrated formation of oligomeric species of the type [M+H]⁺, [2M+H]⁺, [3M+H]⁺, and [4M+H] ⁺. X-ray photoelectron spectroscopy measurements of the deposited films reveals depletion of oxygen at high power which relates well with the greater fragmentation of the monomer detected in the mass spectra.