and the effect of charge screening. Here, we will focus on neutral systems where
electrostatic effects are not relevant.
We will briefly review the available classical theories relevant to both surfactant
and block copolymer micelle kinetics.
2.2.1 Aniansson and Wall Mechanism: Unimer Exchange
and Linear Relaxation Experiments
The Aniansson and Wall theory (A-W theory) [55, 56] was developed for the near
equilibrium relaxation kinetics of neutral low molecular weight micelles. It was
Fig. 2 Illustration of two important mechanisms involved in various kinetic processes in micellar
systems. (a) Unimer exchange, single surfactant/block copolymer chains are interchanged one by
one via the solvent medium. (b) Fusion/fission, where two micelles fuse or are fragmented to
smaller micelles, respectively
Fig. 3 Illustration of a relaxation process from one micellar equilibrium to another upon a small
perturbation, Δ (the reverse perturbation, Δ
0 ) can either be due to a change in an intensive variable
(temperature, pressure, electric field, etc.) or extensive variables such as pH, added salt, etc.
Kinetics of Block Copolymer Micelles Studied by Small-Angle Scattering Methods
67