Thin polymer films from fluidized electrode bed reactors

Abstract

AbstractThe formation and deposition of a polymer as a thin, uniform solid film on a metal particle substrate is investigated in detail in a fluidized electrode bed reactor. Experiments were carried out in different designs of fluidized bed electrode cell reactor, using various metal particles and monomers. It was observed that diacetone acrylamide (DAA) monomer in 0.1N H2SO4 with aluminum particles (3530 μm) as cathode, in a concentric dual compartment cell, appeared to yield the best films. Infrared and elemental analyses were used to characterize the polymer film on the metal particles. Scanning electron microscopy (SEM) was employed to examine the surface and cross‐sectional profiles of the films. The potential profiles in both particulate and solution phases were measured and the importance of particulate electrical conductivity in the polymerization is thus explained. It was observed that the optimum particulate conductivity and hence the maximum yield occurs in the range of 10–20% bed expansion. The experimental product yields for various liquid superficial velocities (i.e., bed expansion) at different feeder current densities were compared to explain the possible controlling mechanism in packed and fluidized bed cells, noting that both chemical reaction and mass transfer control in the low bed expansion region while chemical reaction controls in the high bed expansion region. The current effciency decreases in the high current region due to side reactions at the fluidized bed electrode and due to pore diffusion in the polymer film.