Direct growth of polymer brushes from an electrodeposited conducting poly(dithienylpyrrole) layer functionalized with ATRP initiating moieties

A new strategy for growing polymer brushes using surface-initiated atom transfer radical polymerization (SI-ATRP) from a thin functionalized conducting-polymer layer is reported. Three new heterocyclic monomers based on thiophene and/or pyrrole bearing an ATRP-initiator have been synthesized. Electrochemical behaviour and electrodeposition of these monomers was carried out by both potentiodynamic (CV) and potentiostatic (CA) methods. Remarkably, the use of a tricyclic (2,5-dithienyl)pyrrole-based monomer allowed the formation of a conducting film at a relatively low oxidation potential (onset ∼0.65 V/SCE). Electroactivity characterization showed that conducting, stable and adherent thin polymer layer was formed. The charge-transfer agent was subsequently engaged in SI-ATRP to grow polymethacrylate brushes directly from the conducting functionalized surface. Both the functionalized conducting polymer layer and the resulting tethered polymer brushes were characterized using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). This study confirms that polymethacrylate brushes can efficiently grow directly from a functionalized conducting-polymer thin layer by using a conventional SI-ATRP procedure.