Novel electroconducting polypyrrole/carbon nanotube/alginate nanocomposites synthesized by hydrogen peroxide-mediated emulsion pathway

Abstract

The development of Green-based methods for preparing polypyrrole (PPy)-containing materials with optimal electroactivity still remains a challenge. We herein report a new green approach for the preparation of PPy/carbon nanotube/alginate multifunctional nanocomposites through H2O2 oxidation in micellar medium. The polymerization conditions were systematically varied to optimize the reaction yield and the material electroconductivity. The pre-polymerization emulsion system was studied by contact angle measurements and dynamic light scattering. The results of zeta potential characterization, field-emission scanning electron and atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy are discussed in detail, and a consistent mechanism for the nanocomposite formation is proposed. Interestingly, the synergistic combination of pristine carbon nanotubes and the alginate improves the conductivity and stability of PPy-based colloids. Furthermore, a metoprolol-loaded platform, obtained by the confinement of the synthesized nanocomposite into an alginate network, revealed a cumulative release lesser than 10% after five hours of delivery under passive conditions. This behavior seems to be promising to overcome the undesired burst release in stimulus-controlled drug delivery.