Grafting from surfaces for "everyone": ARGET ATRP in the presence of air.

ABSTRACT

Atom-transfer radical polymerization (ATRP) is one of the controlled/living radical polymerizations yielding well-defined (co)polymers, nanocomposites, molecular hybrids, and bioconjugates. ATRP, as in any radical process, has to be carried out in rigorously deoxygenated systems to prevent trapping of propagating radicals by oxygen. Herein, we report that ATRP can be performed in the presence of limited amount of air and with a very small (typically ppm) amount of copper catalyst together with an appropriate reducing agent. This technique has been successfully applied to the preparation of densely grafted polymer brushes, poly(n-butyl acrylate) homopolymer, and poly(n-butyl acrylate)-block-polystyrene copolymer from silicon wafers (0.4 chains/nm2). This simple new method of grafting well-defined polymers does not require any special equipment and can be carried out in vials or jars without deoxygenation. The grafting for "everyone" technique is especially useful for wafers and other large objects and may be also applied for molecular hybrids and bioconjugates.