Characterization of polystyrene-block-poly (acrylic acid) micelles

Several parameters that affect the formation, size and spatial distribution of micelles of poly(styrene-block-acrylic acid) (PS-b-PAA) in organic solvents or assembled on solid substrates have been investigated. The micelles were characterized in the solvated state using Dynamic Light Scattering, and were imaged and characterized in the dry thin film state using Atomic Force Microscopy. Micelle size in solution followed scaling laws based on the ratio of the two block copolymer segments. Micelle size was not affected by the addition of PS homopolymer or salt, whereas micelle diameter did increase with the addition of PAA homopolymer both in solution and in the dry state on sold supports. Furthermore, micelles formed in toluene, but they did not form in tetrahydrofurane, chloroform or hexane. In terms of spatial distribution in the dry state, the only parameters which affected spacing, and therefore density, were annealing conditions and addition of PAA homopolymer. Annealing near or below the glass transition temperature for 16 hours increased the order of the films, as was demonstrated by Fast Fourier Transforms of their AFM images. Annealing for longer periods of time or at temperatures significantly above the glass transition temperature destroyed the micelles.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Kohen, Naomi (Naomi T.)

Advisor dc:contributor.advisor

• Darrell J. Irvine.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/32846

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32846