Domain formation in block copolymers

Figure 10. Illustration of influence of domain formation in block copolymers according to the models of Helfand and coworkers. The free energy is shown as a function of the size and separation of the domains of varying composition. (The spontaneous separations may be analogous to the way superstructure is formed in natural polymers of plants and animals.)...

Dale Meier has been one of the firsts if not the first who presented a theory of domain formation in block copolymers In its original version Meier s theory was restricted to AB block copolymers and herical domains. In a series of following papers ° , however, Meier has refined his theory considering different shapes of domains, the effect of the presence of a solvent, the dimensions of the interface, the interfacial properties of block copolymers and the solubilization of homopolymers by copolymers. 

Microphase separation and domain formation in block copolymers, which are the result of incompatibility of block chains, have been studied extensively (1,2). In addition to being incompatible, block chains in a copolymer generally have different thermal transition temperatures. The surface tensions of molten block chains also differ. When a crystalline block chain is incorporated into a block copolymer, it is expected that crystallization of the crystalline block chain causes considerable change in resultant morphology. Surface properties of a block copolymer and of its blend with a homopolymer should also be modified by the surface tension difference between block chains and the homopolymer. Since these factors determine the morphological features of a block copolymer both in bulk and at surface, a unified study of morphology, crystallization, and surface activity of any block copolymer is important to our understanding of its physical properties. 

---