Effects of Intermicellar Interactions on the Dissociation of Block Copolymer Micelles: SANS and NMR Studies

Published

February 1, 2014

Author(s)

Gang Cheng, Boualem Hammouda, Dvora Perahia

Abstract

The effects of inter-micellar interactions on the dissociation of block copolymer micelles of polystyrene-b-polyisoprene in a selective solvent, decane, were investigated using small angle neutron scattering (SANS) and ¹H NMR. This well-studied polymer has been used as a model system to correlate intermicellar interactions with overall micellar stability. Decane is a preferential solvent for polyisoprene (PI) and drives the association of the polystyrene (PS) blocks, resulting in spherical micelles with a PS core and a Gaussian PI corona. The dissociation of PS-PI micelles was triggered by increasing temperature, while the inter-micellar interactions were controlled by varying the polymer concentration and modulating temperature. With increasing temperature, the cores of the micelles first swell, followed by a breakdown to smaller micelles, with similar shapes, that eventually dissociate into single molecules. Herein, we have shown for the first time that enhancing the inter-micellar interaction delays the dissociation process of the micelles.

Citation

Macromolecular Chemistry and Physics

Volume

215

Issue

4

Pub Type

Journals

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Keywords

micelles, copolymers, small-angle neutron scattering

Citation

Cheng, G. , Hammouda, B. and Perahia, D. (2014), Effects of Intermicellar Interactions on the Dissociation of Block Copolymer Micelles: SANS and NMR Studies, Macromolecular Chemistry and Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914933 (Accessed December 7, 2024)