Facile preparation of transition metal nanoparticles stabilized by well-defined (co)polymers synthesized via aqueous reversible addition-fragmentation chain transfer polymerization

Herein we disclose a facile method for the preparation of (co)polymer-stabilized transition metal colloids, via the "grafting-to" approach. The method takes advantage of the fact that (co)polymers synthesized in aqueous media, in a controlled fashion, via reversible addition-fragmentation chain transfer bear thiocarbonylthio end groups. These are readily reduced to yield (co)polymers with thiol end groups. When the reduction is performed, with NaBH(4), for example, in aqueous media in the presence of an appropriate transition metal species, (co)polymer-stabilized metal nanoparticles are formed in which the size and size distribution are dependent upon the individual transition metals. Colloid formation is confirmed by transmission electron microscopy and UV-vis spectroscopy.

Well-defined sulfobetaine-based statistical copolymers as potential antibioadherent coatings

The potential use of novel poly(sulfobetaine) copolymers as antibioadherent coatings was investigated using Pseudomonas aeruginosa as a model microorganism and human macrophages and 3T3 mouse embryonic fibroblasts. Two well-defined statistical copolymers with narrow molecular weight distributions were prepared by group transfer copolymerization of n-butyl methacrylate (nBuMA) with either 10 or 30 mol % 2-(dimethylamino)ethyl methacrylate (DMAEMA). Sulfobetainized nBuMA-DMAEMA copolymers (poly[sulfobetaine-stat-nBuMA]) were obtained by treating these precursor polymers with 1,3-propanesultone under mild conditions. Both proton NMR spectroscopy and elemental microanalyses indicated that essentially all the DMAEMA residues were derivatized in both copolymers. Poly(methyl methacrylate) (PMMA) discs were coated with the sulfobetainized nBuMA-DMAEMA copolymers and the bioadherent properties of these coated materials were compared with those of PMMA. Statistically significantly fewer (p<.05) bacteria, macrophages, and fibroblasts adhered to the poly(sulfobetaine-stat-nBuMA)-coated PMMA than to the uncoated PMMA. The poly(sulfobetaine-stat-nBuMA) copolymer containing the higher proportion (30 mol %) sulfobetainized DMAEMA residues proved to be the more effective antibioadherent coating. The antibioadherent properties of these coating materials may allow the cost-effective production of dirt-resistant, easy to clean work surfaces, bioinert coatings for medical devices, and antifouling coatings for marine, agricultural, and industrial applications.