Structure, interactions, and dynamics in tethered chain systems
- Stanford Univ., CA (United States)
We use the self-assembling nature of diblock copolymers in selective solvents to produce monodisperse spherical micelles. These micelles provide a valuable model system to study chains tethered to curved interfaces. They provide a means to alter the topology of the anchoring interface as well as the tethered chain length through variations in the diblock copolymer degree of polymerization. A polymer chain layer that is thin compared to the core radius has highly extended chains resembling a polymer brush structure. Polymers in micelles having small spherical cores have a structure similar to that found in star polymers. We study polymeric micelles and their interactions via small angle light, X-ray, and neutron scattering. We model the tethered layer structures via self-consistent field theory and combine this with liquid state theory to predict the structure in concentrated suspensions of micelles. We compare the liquid structure determined from small angle neutron scattering to that predicted from our statistical mechanical models. The disorder to order transition is profoundly influenced by small changes in the micellar structure; micelles having larger cores form face centered cubic arrays while more starlike structures order into body centered cubic crystals. The crystal structure has a great influence on the suspension rheology. We briefly review the structural transitions occurring during simple shear of these arrays. 72 refs., 11 figs., 1 tab.
- OSTI ID:
- 374510
- Journal Information:
- Langmuir, Journal Name: Langmuir Journal Issue: 17 Vol. 12; ISSN LANGD5; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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