symmetries. The recent development is from the collaboration between Shi and the
research group of Yang and Qiu (Guo et al. 2008 ; Zhang et al. 2010 ). They searched for
all the stable symmetric phases of block copolymers from the solutions of SCF
equations in the reciprocal Fourier-space. This approach allows the search for more
complicated microdomain structures in triblock and multi-block copolymer systems,
more complicated than the diblock copolymer systems.
The theoretical methods to investigate the evolution kinetics of ordered
microdomain structures are those in the atomic-scale including molecular dynamics
simulations, Monte Carlo simulations, dynamic SCFT, dynamic density functional
theory (DDFT), and those in the meso-scale including dissipative particle dynamics
(DPD) simulations, etc. More details of these approaches can be found in the
literatures.
Multi-block copolymers can form a greater variety of ordered phase structures
than diblock copolymers, via self-assembly. Some of them have been widely
applied as the matrix materials, such as styrene-butadiene-styrene (SBS) thermal
elastomers, acrylonitrile-butadiene-styrene (ABS) copolymers and polyurethanes.
In a selective solvent, block copolymers with intramolecular multi-components
can even form various geometric shapes of micelles and vesicles. In particular in
aqueous solutions, the self-assembly of amphiphilic copolymers is neatly
associated with that of bio-macromolecules in the life systems. In the field of
macromolecular assembly, the research approach concerted with experimental
observations, theoretical calculations and molecular simulations harvests new
achievements. Jiang and his collaborators developed the “non-covalent connection”
route of macromolecular self-assembly, i.e. connecting different polymer chains
(either homopolymers or random copolymers) via specific interactions in the
supermolecular chemistry, such as hydrogen bonding, host-guest inclusion complex
interactions, etc. (Chen and Jiang 2005 ; Guo and Jiang 2009 ). In a selective solvent,
they can self-assemble into non-covalently connected micelles (NCCM), vesicles
Fig. 9.14Illustration of phase diagrams for various ordered phase structures and their segregation
strengths changing with compositions in diblock copolymers
9.3 Microphase Separation of Diblock Copolymers 183