Adv Polym Sci (2013) 259: 51–158
DOI: 10.1007/12_2012_204
# Springer-Verlag Berlin Heidelberg 2013
Published online: 11 August 2012
Kinetics of Block Copolymer Micelles Studied
by Small-Angle Scattering Methods
Reidar Lund, Lutz Willner, and Dieter Richter
Abstract This article reviews recent progress in studying the kinetics of block
copolymer micellar systems by time-resolved small angle scattering techniques. The
review includes an overview of the theoretical background concerning block copolymer micellar structure and kinetics, with a clear distinction between equilibrium and
non-equilibrium processes. Basic principles of both static and time-resolved smallangle X-ray and neutron scattering (TR-SAXS and TR-SANS) techniques are
summarized, with a special emphasis on the characterization of block copolymer
micellar systems. In particular, the principle of SANS in combination with hydrogen/
deuterium (H/D) contrast variation for the determination of chain exchange under
equilibrium conditions is highlighted. In the experimental part, we first review results
on equilibrium kinetics obtained within the last decade by the TR-SANS/H/D labeling
technique. In general, the experimental results strongly indicate that the component
exchange between different micelles proceeds via the exchange of single unimers. In
agreement with the theoretical prediction, chain expulsion is the rate-determining
step. The corresponding activation energy is mainly governed by the interfacial
tension and the length of the insoluble block, which determine the exchange rate
with a double exponential dependence. Thus, due to this extremely strong dependence, even synthetic polymers with modest chain length distribution show a logarithmic time dependence instead of the theoretically expected single exponential
decay. In the second part, the kinetic results obtained under non-equilibrium
conditions, i.e., relaxation processes obtained after perturbations from equilibrium,
are reviewed. This part covers formation kinetics as well as reorganization and
morphological transition kinetics. We present, as a special highlight, TR-SAXS
R. Lund (*)
Department of Chemistry, University of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway
e-mail: reidar.lund@kjiemi.uio.no
L. Willner (*) and D. Richter
Ju ¨lich Centre for Neutron Science JCNS and Institute for Complex Systems ICS,
Forschungszentrum Ju ¨lich GmbH, 52425 Ju ¨lich, Germany
e-mail: l.willner@fz-juelich.de; d.richter@fz-juelich.de
DOI: 10.1007/12_2012_204
# Springer-Verlag Berlin Heidelberg 2013
Published online: 11 August 2012
Kinetics of Block Copolymer Micelles Studied
by Small-Angle Scattering Methods
Reidar Lund, Lutz Willner, and Dieter Richter
Abstract This article reviews recent progress in studying the kinetics of block
copolymer micellar systems by time-resolved small angle scattering techniques. The
review includes an overview of the theoretical background concerning block copolymer micellar structure and kinetics, with a clear distinction between equilibrium and
non-equilibrium processes. Basic principles of both static and time-resolved smallangle X-ray and neutron scattering (TR-SAXS and TR-SANS) techniques are
summarized, with a special emphasis on the characterization of block copolymer
micellar systems. In particular, the principle of SANS in combination with hydrogen/
deuterium (H/D) contrast variation for the determination of chain exchange under
equilibrium conditions is highlighted. In the experimental part, we first review results
on equilibrium kinetics obtained within the last decade by the TR-SANS/H/D labeling
technique. In general, the experimental results strongly indicate that the component
exchange between different micelles proceeds via the exchange of single unimers. In
agreement with the theoretical prediction, chain expulsion is the rate-determining
step. The corresponding activation energy is mainly governed by the interfacial
tension and the length of the insoluble block, which determine the exchange rate
with a double exponential dependence. Thus, due to this extremely strong dependence, even synthetic polymers with modest chain length distribution show a logarithmic time dependence instead of the theoretically expected single exponential
decay. In the second part, the kinetic results obtained under non-equilibrium
conditions, i.e., relaxation processes obtained after perturbations from equilibrium,
are reviewed. This part covers formation kinetics as well as reorganization and
morphological transition kinetics. We present, as a special highlight, TR-SAXS
R. Lund (*)
Department of Chemistry, University of Oslo, Postboks 1033 Blindern, 0315 Oslo, Norway
e-mail: reidar.lund@kjiemi.uio.no
L. Willner (*) and D. Richter
Ju ¨lich Centre for Neutron Science JCNS and Institute for Complex Systems ICS,
Forschungszentrum Ju ¨lich GmbH, 52425 Ju ¨lich, Germany
e-mail: l.willner@fz-juelich.de; d.richter@fz-juelich.de