Electrochemically instantaneous reduction of conducting polyaniline-coated latex particles dispersed in acidic solution

概要

論文の詳細を見る
A cathodic voltammetric wave was observed in an aqueous suspension ofmono-dispersed, spherical polyaniline-coated polystyrene particles, whereas no anodicwave was detected. This irreversibility was common to particles with eight differentdiameters ranging from 0.2 to 7.5 μm. Such irreversibility cannot be found atpolyaniline-coated electrodes, and thus is a property of the dispersion of polyanilinelatex. The reduction current was controlled by diffusion of dispersed particles. Thereduction, being the conversion from the electrical conducting state to the resistive one,should begin at a point of contact between the conducting particle and the electrode inorder to be propagated to the whole particle rapidly. In contrast, the oxidation proceedsslowly with the propagation of conducting zone, during which Brownian motion lets theparticle detach from the electrode. The number of loaded aniline units per particle,determined by weight analysis, ranged from 6×10_6 (φ 0.2 μm) to 3×10_11 (φ 7.5 μm) andwas proportional to 2.9 powers of the particle diameter. The diffusion-controlled currentof the cathodic wave was proportional to 2.4 powers of the diameter. The difference inthese powers, 0.5, agreed with a theoretical estimation of the diffusion-controlledcurrent, the diffusion coefficient for which was given by the Stokes-Einstein equation.
Elsevier Scienceの論文
2008-00-00