Dilute Solution Properties and Aggregation Behavior of Alternate Hetero-arm Copolymer Brushes

✍ Scribed by Keiichiro Tsubaki; Hiroaki Kobayashi; Junichiro Sato; Koji Ishizu

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 128 KB
• Volume: 241
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.2001.7654

✦ Synopsis

Alternate hetero-arm copolymer brushes were synthesized by free-radical copolymerizations of vinylbenzyl-terminated polystyrene macromonomers (PS-VB) with a methacryloyl-terminated poly(ethylene oxide) macromonomer (PEO-MA)/tin tetrachloride (SnCl 4 : Lewis acid) complex. Dilute solution properties of such hetero-arm copolymer brushes were investigated by static and dynamic light scattering. Effective diffusion coefficients D eff for copolymer brushes possessing large aspect ratios showed almost constant values in the range of polymer concentrations 0-6 × 10 -3 g/cm 3 . These results mean that copolymer brushes formed unimolecular structures even in a good solvent such as benzene. It was speculated from angular dependence measurements that in solution copolymer brushes take geometrically anisotropic conformations such as cylinders. To determine the phase-separated cylindrical domains of alternate copolymer brushes, we constructed large aggregates of copolymer brushes in water. Consequently, alternate copolymer brushes seemed to lead self-assemblies among phaseseparated hydrophobic PS domains.