Synthesis and layer-by-layer deposition of spherical poly(3,4-ethylenedioxythiophene) nanoparticles -: Toward fast switching times between reduced and oxidized states

A microemulsion polymerization for the synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles is described. Spherical and electrically conducting PEDOT particles with diameters as small as 27 +/- 8 nm were obtained by using decyltrimethylammonium bromide as a cationic surfactant. PEDOT nanoparticle multilayers, alternated with poly(styrene sulfonate), were prepared by the layer-by-layer deposition technique. Electrochemcal surface plasmon resonance experiments revealed a ten-fold increase in the switching time between redox states as compared with Baytron P/poly(ethyleneimine) multilayers. The enhanced charge transport can be attributed to an improved diffusion of the charge-balancing counterions into the PEDOT nanoparticles.