Spatio-resolved, macromolecular architectural surface: Highly branched graft polymer via photochemically driven quasiliving polymerization technique

We present a new method for highly spatio-resolved graft-copolymerized surface fabrication, in which the stem design (parent graft chain length) and the branch design (daughter graft chain length and degree of branching) are relatively well controlled. This is based on the photochemistry of the benzyl N,N-diethyldithiocarbamate (DC) group that acts as an initiator-transfer-terminator (iniferter) agent. DC-derivatized glass was used as the substrate. Ultraviolet light irradiation of the DC-derivatized glasses in the presence of chloromethylstyrene (CMS) produced polyCMS-graft-polymerized surfaces with different chain lengths (parent graft), depending on the irradiation time. Subsequent dithiocarbamylation of the CMS unit and irradiation in the presence of sodium methacrylate resulted in the formation of a macromolecular architectural surface in which lengths of both parent and daughter chains in graft copolymers were controlled by the irradiation time. The degree of branching was found to be controlled by CMS content in the parent graft chains which were prepared by graft copolymerization of CMS with N,N-dimethylacrylamide. These were verified by fluorescence intensity measurements of malachite green-stained samples using a confocal scanning laser microscope.