Synthesis of Conductive Core−Shell Nanoparticles Based on Amphiphilic Starburst Poly(n-butyl acrylate)-b-poly(styrenesulfonate)

A synthetic route for highly stable electrically conductive core−shell nanoparticle was developed. It involves the synthesis of multiarmed poly( n -butyl acrylate- b -polystyrene) (PBA- b -PS) starburst block copolymers via the atom transfer radical polymerization method from polyfunctional initiators under very dilute condition using n -butyl acrylate and styrene as monomers, sequentially. Both NMR and gel permeation chromatography analyses reveal that the as-synthesized copolymers had a well-controlled molecular weight with a polydispersity of below 1.2. Then, the outer PS shell of the star copolymer was converted into hydrophilic poly( p -styrenesulfonate) with acetyl sulfate to generate amphiphilic PBA- b -PSS unimolecular micelles. The 1 H NMR spectrum confirmed that a sulfonation of almost 100% was reached without hydrolysis of the side butyl ester chain on PBA blocks. Finally, the oxidative propagation of 3,4-ethylenedioxythiophene (EDOT) on the PSS chains was carried out by counterion-induced polymerization to produce a stable aqueous dispersion of star-shaped PBA- b -PSS/PEDOT complex, which can be visualized as a conducting core−shell nanoparticle. The obtained products were characterized by FT-IR and UV−vis spectroscopy. All thin films prepared by casting from 4-, 6-, and 12-armed complexes exhibited excellent flexibility and strong adhesion to glass substrate; their conductivities were determined by the four-point probe method to be 6.7, 4.9, and 6.8 mS/cm, respectively.