SEARCH

SEARCH BY CITATION

Keywords:

  • conducting polymers;
  • electrodes;
  • polymeric materials;
  • thermoelectrics

Abstract

Metal ions (Ag+, Cu2+, Hg2+) are incorporated into an electropolymerized, poly(N-isopropyl acrylamide), pNIPAM, thermosensitive polymer associated with an electrode using the “breathing-in” method. The ion-functionalized pNIPAM matrices reveal ion-dependent gel-to-solid phase-transition temperatures (28 ± 1 °C, 25 ± 1 °C, 40 ± 1 °C for the Ag+, Cu2+, and Hg2+-modified pNIPAM, respectively). Furthermore, the ion-functionalized polymers exhibit quasi-reversible redox properties, and the ions are reduced to the respective Ag0, Cu0, and Hg0 nanocluster-modified polymers. The metal-nanocluster-functionalized pNIPAM matrices enhance the electron transfer (they exhibit lower electron-transfer resistances) in the compacted states. The electron-transfer resistances of the metal-nanocluster-modified pNIPAM can be cycled between low and high values by temperature-induced switching of the polymer between its contracted solid and expanded gel states, respectively. The enhanced electron-transfer properties of the metal nanocluster-functionalized polymer are attributed to the contacting of the metal nanoclusters in the contracted state of the polymers. This temperature-switchable electron transfer across a Ag0-modified pNIPAM was implemented to design a thermo-switchable electrocatalytic process (the temperature-switchable electrocatalyzed reduction of H2O2 by Ag0-pNIPAM).