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

• Published in: Journal of colloid and interface science Vol. 241; no. 1; pp. 275 - 279
• Main Authors: Tsubaki, Keiichiro, Kobayashi, Hiroaki, Sato, Junichiro, Ishizu, Koji
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.09.2001; Elsevier
• Subjects: alternate hetero-arm copolymer brushes; Applied sciences; Copolymerization; Exact sciences and technology; Organic polymers; phase-separated cylinder brushes; Physicochemistry of polymers; Preparation, kinetics, thermodynamics, mechanism and catalysts; unimolecular structure; alternate hetero-arm copolymer brushes; phase-separated cylinder brushes; unimolecular structure; Terpolymer; Comb copolymer; Graft copolymer; Radius of gyration; Ethylene oxide copolymer; Experimental study; Ethylene oxide polymer; Translational diffusion; Solution structure; Preparation; Concentration effect; Dilute solution; Ethyl methacrylate copolymer; Styrene polymer; Molecular aggregation; Radical copolymerization; Conformation; Styrene copolymer
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.2001.7654

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 (SnCl4: Lewis acid) complex. Dilute solution properties of such hetero-arm copolymer brushes were investigated by static and dynamic light scattering. Effective diffusion coefficients Deff for copolymer brushes possessing large aspect ratios showed almost constant values in the range of polymer concentrations 0–6×10−3 g/cm3. 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 phase-separated hydrophobic PS domains.