Mechanism of molecular exchange in diblock copolymer micelles: hypersensitivity to core chain length.
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).
Choi
Soo-Hyung
SH
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Lodge
Timothy P
TP
Bates
Frank S
FS
D008823:Micelles; D033363:Neutron Diffraction; D011108:Polymers / Q000737:chemistry*; D053838:Scattering, Small Angle; D013696:Temperature; D013997:Time Factors
D008823:Micelles; D011108:Polymers