Dynamics of self-assembled systems studied by neutron scattering: Current state and perspectives
Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC 7, 10623 Berlin, Germany
Revised: 27 September 2012
Published online: 3 December 2012
In general self-assembled systems, composed of building blocks and aggregates, exhibit rather complex dynamic properties, which so far are only poorly understood, despite their high importance both for fundamental understanding and applications. Due to their typical sizes of 2-200 nm they are in general very suited for investigations by means of neutron scattering. This has been exploited extensively for the determination of their static mesoscopic structure but is similarly feasible for the investigation of their dynamic properties. This review gives an overview about investigations done so far by means of neutron scattering with respect to time-dependent properties of self-aggregating systems. In general, two types of studies can be distinguished: dynamics under equilibrium conditions (e.g. structural fluctuations) or morphological changes as a function of time (non-equilibrium). In the first case typically inelastic neutron scattering is applied in order to obtain information about dynamic properties of the systems, such as membrane elasticity or movements in membranes. The other direction of experiments are kinetic investigations of changes of the mesoscopic structure in self-aggregating systems after changing composition, temperature or other external parameters, which are mostly followed by time-resolved SANS. These investigations have given substantial new insight into morphological changes occurring in self-assembling systems and altered our view on it. This field of “mesodynamics” is still an emerging research topic of colloid science but neutron scattering has already contributed substantially to it and will certainly do much more so in the future. Especially as for more complex systems neutron scattering with its flexibility in contrast allows to obtain unique structural and dynamical information. This will certainly be of central importance for developing our understanding of more complex self-assembled systems further and also lead to new approaches for bringing them to novel applications.
© EDP Sciences, Springer-Verlag, 2012