Characterization of the Effects of Varying the pH and Monomer Concentrations of Poly(oxyphenylene) Insulating Films on Carbon Fiber Electrodes

By varying the conditions of an electrodeposition solution containing phenol and 2-allylphenol, thin poly(oxyphenylene) films can be formed. These films have been used to insulate flame-etched carbon fiber electrodes to produce smaller electrode tip diameters. Experiments have been performed to test both the insulating properties and the film thickness of this poly(oxyphenylene) copolymer at pH 5.0, 7.0, and 9.0. The effects of monomer concentration on the polymer insulation integrity and film thickness have also been investigated. These experiments show that a decrease in pH results in thinner insulating films. It is also shown that monomer concentration can be decreased to 12mM phenol/18mM 2-allylphenol without causing an appreciable change in the insulating properties of the copolymer film; however, as the concentration is decreased, the pH appears to have less influence on the copolymer thickness.