Electroactive self-standing polyester membranes prepared using magnetite/poly(3,4-ethylenedioxythiophene) core-shell particles

In this work hybrid magnetite (Fe₃O₄)/poly(3,4-ethylenedioxythiophene) (PEDOT) core-shell particles are used to produce electro-responsive self-standing polycaprolactone (PCL) membranes with many potential applications. For this purpose, Fe₃O₄/PEDOT core-shell particles with different magnetite contents are prepared by combining chemical precipitation and emulsion polymerization. After chemical, morphological and physical characterization, the electrochemical response of the hybrid particles is analyzed and compared with that of PEDOT nanoparticles. In all cases, Fe₃O₄/PEDOT core-shell particles are more electroactive than PEDOT particles, with the electrochemical response of the former increasing with the content of magnetite. Composite membranes were prepared by spin-coating a mixture of polycaprolactone (PCL) and Fe₃O₄/PEDOT particles. The resulting Fe₃O₄/PEDOT-PCL membranes, which maintained the magnetic behavior, were transformed into electro-responsive by incorporating a PEDOT surface layer through anodic polymerization, which was possible thanks to the role of Fe₃O₄/PEDOT particles as polymerization nuclei. One of the potential applications of self-supported electro-responsive Fe₃O₄/PEDOT-PCL/PEDOT membranes was illustrated through a proof-of-concept. Specifically, a wide-spectrum antibiotic, chloramphenicol, was loaded into the membranes during the anodic polymerization step promoted by the hybrid Fe₃O₄/PEDOT particles and, subsequently, completely released by electrical stimulation. Overall, Fe₃O₄/PEDOT core-shell particles allowed us to obtain self-standing membranes with electric and magnetic properties, as promising candidates for many technological applications.