<p> Self-consistent field theory (SCFT) is a well established theoretical framework for
describing the thermodynamics of block copolymer melts and blends. Combined with
numerical methods, the SCFT can give useful and accurate predictions regarding the
phase behavior of polymer blends. </p> <p> We have applied SCFT to study the phase behavior of blends composed of diblock
copolymers (AB) and homopolymers (C). Two cases are studied in detail. In the
first case the homopolymers have a repulsive interaction to the diblock copolymers.
We found an interesting feature in the phase diagram that there exists a bump of
the phase boundary line when A is the majority-component. In the second case,
the homopolymers have an attractive interaction to one of the blocks of the diblock
copolymers. A closed-loop of microphase separation region forms for strong interactions.
For both cases, we have investigated the effects of homopolymer concentration,
homopolymer chain length, and monomer-monomer interactions, on the phase behavior
of the system. </p> <p> We also investigated micelle formation in polymer blends. Diblock copolymers (AB)
blended with homopolymers (A) can self-assemble into lamellar, cylindrical and spherical
micelles. The critical micelle concentrations for different geometries are determined
using self-consistent field theory. The effect of varying copolymer block asymmetry,
homopolymer molecular weight and monomer-monomer interactions on micelle
morphology are examined. \\Then the blends are confined between two flat surfaces,
the shape of the micelles may differ from that of the bulk micelles. We study the
shape variation of a. spherical micelle under confinement and its dependence on the
film thickness and surface selectivity. </p> / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19408 |
| Date | 12 1900 |
| Creators | Zhou, Jiajia |
| Contributors | Shi, An-Chang, Physics and Astronomy |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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