Electropatterning of binary polymer brushes by surface-initiated RAFT and ATRP

A new, simple, and effective method for preparing binary patterned brushes by electrodeposition and self-assembly is presented. The technique involves the use of electrochemistry to immobilize a chain transfer agent (CTA) on a patterned conducting substrate that mediate surface-initiated polymerization (SIP) through a reversible addition-fragmentation chain transfer (RAFT) process. The non-electropatterned surfaces were then backfilled with self-assembly of an atom transfer radical polymerization (ATRP) silane initiator where the polymerization of the next brush was initiated. The use of techniques such as RAFT and ATRP is well known to give a controlled polymerization mechanism, which would be of great advantage in generating binary patterned brushes. FT-IR imaging was used to analyze these films. Patterned binary polymeric materials on surfaces are of interest for attaching unique chemical functionalities and properties on selected regions of the surface. The fabrication of patterned binary brushes on ITO-glass substrate via electrodeposition and living radical polymerization techniques is demonstrated. The patterned polymers are visually characterized via AFM and optical microscopy and are chemically-mapped by FT-IR imaging.