High-Pressure Micellar Solutions of Polystyrene-block-Polybutadiene and Polystyrene-block-Polyisoprene Solutions in Propane Exhibit Cloud-Pressure Reduction and Distinct Micellization End Points

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Macromolecules

DOI:https://doi.org/10.1021/ma900848j· OSTI ID:967981

Winoto, Winoto ^[1]; Radosz, Maciej ^[1]; Tan, Sugata ^[1]; Hong, Kunlun ^[2]; Mays, Jimmy ^[2]

---

1. University of Wyoming, Laramie
2. ORNL

Micellar solutions of polystyrene-block-polybutadiene and polystyrene-block-polyisoprene in propane are found to exhibit significantly lower cloud pressures than the corresponding hypothetical non-micellar solutions. Such a cloud-pressure reduction indicates the extent to which micelle formation enhances the apparent diblock solubility in near-critical and hence compressible propane. Pressure-temperature points beyond which no micelles can be formed, referred to as the micellization end points, are found to depend on the block type, size and ratio, and on the polymer concentration. For a given pressure, the micellization end-point temperature corresponds to the "critical micelle temperature." The cloud-pressure reduction and the micellization end point measured for styrene-diene diblocks in propane should be characteristic of all amphiphilic diblock copolymer solutions that form micelles in compressible solvents.

• Research Organization: Oak Ridge National Laboratory (ORNL); Center for Nanophase Materials Sciences
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 967981
• Journal Information: Macromolecules, Journal Name: Macromolecules Journal Issue: 18 Vol. 42
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
BUTADIENE
COPOLYMERS
MICELLAR SYSTEMS
ORGANIC POLYMERS
POLYISOPRENE
POLYSTYRENE
PRESSURE DEPENDENCE
SOLUBILITY
TEMPERATURE DEPENDENCE