6533b7cefe1ef96bd1257919
RESEARCH PRODUCT
Critical micellization density: A small-angle-scattering structural study of the monomer-aggregate transition of block copolymers in supercriticalCO2
R. TrioloAlessandro TrioloF. Lo CelsoFabio TrioloFabio TrioloJames B. McclainGeorge D. WignallDouglas E. BettsJoseph M. Desimonesubject
chemistry.chemical_classificationchemistry.chemical_compoundMonomerMaterials sciencechemistryCopolymerMoleculeThermodynamicsPolymerSmall-angle scatteringMicelleSupercritical fluidRandom coildescription
In this paper we report a small-angle neutron-scattering investigation of micelle formation by the fluorocarbon-hydrocarbon block copolymer, polyvinyl acetate-b-poly (1,1,2,2-tetrahydroperfluoro-octyl acrylate) in supercritical CO{sub 2} (scCO{sub 2}) at 313 K. At high pressure the copolymer is in a monomeric state with a random coil structure, while at low pressure the polymer forms spherical aggregates stable in a wide range of thermodynamic conditions. By profiling pressure, a sharp monomer-micelle transition is obtained due to the tuning of the solvating ability of scCO{sub 2}. We confirm the previous finding that this aggregate-monomer transition is driven by the gradual penetration of CO{sub 2} molecules toward the core of the aggregate and is critically related to the density of the solvent, thus giving additional support to the concept of a critical micellization density reported earlier on a similar polymer.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2000-10-01 | Physical Review E |