Investigation of styrene-methacrylic acid block copolymer micelle doped polypyrrole films by scanning electrochemical microscopy

The preparation of a novel type of polypyrrole films is described. Spherica l styrene-methacrylic acid block copolymer micelles with a hydrophobic core of Is nm and a hydrophilic corona of 100 nm were incorporated in polypyrro le films by electropolymerization from a mixed solvent with 80 vol % of dio xane and 20 vol % of water. The properties of the block copolymer micelle d oped polypyrrole films were investigated by cyclic voltammetry and scanning electrochemical microscopy (SECM). It was found that the self-assembled bl ock copolymer micelles in polypyrrole behave as polyanions and the charge c ompensation by cations has been identified during electrochemical switching of the polymer films. The ejection of cations from the films was monitored by SECM using an amperometric or potentiometric ultramicroelectrode tip du ring different potential programs (potential step and cyclic voltammetric s cans) applied on the block copolymer micelle doped polypyrrole modified sub strate electrodes. The incorporation of self-assembled block copolymer mice lles into the polypyrrole structure can represent an interesting way to cha nge its properties. Different kinds of hydrophobic molecules can be dissolv ed in the core of the micelle and thus incorporated into the polypyrrole fi lms.