Effects of Cationic Polymer Colloidal Particle Size on the Reactivity of Organic Anions

Abstract

The diameters of small spherical polymeric particles on the order of 2 x 10-7 m, known as polymer latexes, are 1000-10000 times smaller than polymer resins. Their internal structures are entangled polymer coils with ionic functional groups so that they can be used as highly efficient catalytic media to promote various types of reactions such as decontamination of chemical warfare agents and insecticides in the field. Since the rates of reactions catalyzed by polymer beads are limited by slow transfer of one or both reactants to the active sites inside particles, these smaller colloidal polymer particles used as catalytic media have advantages due to their high surface areas and the short paths to the active sites. This research investigated the effects of particle size on the catalytic activity by using cationic polystyrene particles having average diameter of 20 nm, 135 nm, and 1 �m as catalytic media. These three different size particles showed different reaction rates. The kinetics with particles 1 �m in diameter had a retardation period at the beginning of the reaction process. This work verified that polymer latex particles < 1 Jlrn never suffered diffusional limitations to reaction rates.