The preparation of conducting polyaniline-silver and poly(p-phenylenediamine)-silver nanocomposites in liquid and frozen reaction mixtures
Abstract
The oxidation of aniline with silver nitrate in 1 mol LMINUS SIGN 1 acetic acid at 20 oC yielded a composite of two conducting components, polyaniline and silver; the acceleration with 1 mol% of p-phenylenediamine is needed for efficient synthesis. The yield and molecular weight increased when aniline was copolymerized with 10 mol% p-phenylenediamine.
Such product displayed metallic conductivity below 180 K and semiconductor type above this temperature. As the result, the conductivity was the same at 100 and 300 K.
The oxidation of p-phenylenediamine alone with silver nitrate also produced a conducting composite having the conductivity of 1,750 S cmMINUS SIGN 1 despite the assumed nonconductivity of poly(p-phenylenediamine). The present study demonstrates that all oxidations proceeded also in frozen reaction mixtures at MINUS SIGN 24 oC, i.e., in the solid state.
In most cases, molecular weights of polymer component increased, the conductivity of composites with silver improved, to 2,990 ScmMINUS SIGN 1 for poly(p-phenylenediamine)- silver, and remained high after deprotonation with 1 mol LMINUS SIGN 1 ammonium hydroxide.