Course of poly(4-aminodiphenylamine)/Ag nanocomposite formation through UV–vis spectroscopy

Kinetics of chemical oxidative polymerization of 4-aminodiphenylamine (4ADPA) was followed in aqueous 1 M p-toluene sulfonic acid (p-TSA) using silver nitrate (AgNO3) as an oxidant by UV–vis spectroscopy. The medium was found to be clear and homogeneous during the course of polymerization. The absorbances corresponding to the intermediate and the polymer were followed for different concentrations of 4ADPA and AgNO3 and at different reaction time. The appearance of a band around 450 nm during the initial stages of polymerization corresponds to the plasmon resonance formed by the reduction of Ag+ ions. Rate of poly(4-aminodiphenylamine)/Ag nanocomposite (RP4ADPA/AgNC) was determined for various reaction conditions. RP4ADP/AgNC showed second order power dependence on 4ADPA and first order dependence on AgNO3. The observed order dependences of 4ADPA and AgNO3 on the formation of P4ADPA/AgNC were used to deduce a rate equation for the reaction. Rate constant for the reaction was determined through different approaches. The good agreement between the rate constants obtained through different approaches justifies the selection of rate equation.

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► Kinetics of poly(4-aminodiphenylamine)/silver nanocomposite (P4ADPA/AgNC) formation has been monitored by UV–vis spectroscopy.
► AP4ADPA/AgNC was formed after a very short induction period (around 3 min).
► The steady increase in absorbances around 410 and beyond 700 nm corroborates with the increase in the amount of nanocomposite.
► Rate of nanocomposite follows a second order dependence with respect to 4ADPA and first order with respect to AgNO3.