Related Experiment Video
Updated: Jun 14, 2026

Measuring the Time-Evolution of Nanoscale Materials with Stopped-Flow and Small-Angle Neutron Scattering
Published on: August 6, 2021
Mechanism of molecular exchange in diblock copolymer micelles: hypersensitivity to core chain length
Soo-Hyung Choi1, Timothy P Lodge, Frank S Bates
1Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Abstract:
Molecular exchange between spherical micelles formed from isotopically labeled diblock copolymers was investigated using time-resolved small-angle neutron scattering measurements. Temperature changes affect the micelle exchange rate R(t) consistent with melt dynamics for the core polymer. Varying the core block length N produces gigantic changes in R(t) due to the thermodynamic penalty associated with ejecting a core block into the surrounding solvent. This hypersensitivity, combined with modest polydispersity in N, leads to an approximately logarithmic R(t).
Related Concept Videos
Cationic Chain-Growth Polymerization: Mechanism
Micelles
Anionic Chain-Growth Polymerization: Mechanism
Characteristics and Nomenclature of Copolymers
π Electron Effects on Chemical Shift: Overview
Determination of Molar Masses of Polymers I

