Structures of PEP–PEO Block Copolymer Micelles: Effects of Changing Solvent and PEO Length and Comparison to a Thermodynamic Model
Publication: Research - peer-review › Journal article – Annual report year: 2012
Structures of poly(ethylene propylene)–poly(ethylene oxide) (PEP–PEO) block copolymer micelles were determined from small-angle X-ray scattering and static light scattering and compared to predictions from a thermodynamic model. Both the corona block length and the solvent water–ethanol ratio were changed, leading to a thorough test of this model. With increasing ethanol fraction, the PEP core–solvent interfacial tension decreases, and the solvent quality for PEO changes. The weight-average block masses were 5.0 kDa for PEP and 2.8–49 kDa for PEO. For the lowest PEO molar mass and samples in pure water (except for the highest PEO molar mass), the micelles were cylindrical; for other conditions they were spherical. The structural parameters can be reasonably well described by the thermodynamic model by Zhulina et al. [Macromolecules2005, 38 (12), 5330–5351]; however, they have a stronger dependence on solvent composition and PEO molar mass than predicted.
|Citations||Web of Science® Times Cited: 1|
- Small angle X-ray scattering, Organic solvents, Water-ethanol, Thermodynamic properties, Solvents, Thermodynamic model, Solvent composition, Block copolymers, Propylene, Pure water, Polyethylene oxides, Static Light Scattering, Scattering, Block copolymer micelles, X ray scattering, Micelles, Structural parameter, Block lengths, Solvent quality, Ethylene, Ethanol