Spherical domains, block copolymers

Segalman RA, Yokoyama H, Kramer EJ (2001) Graphoepitaxy of spherical domain block copolymer films. Adv Mater 13 1152... 

Segahnan, R.A., Hexemer, A. et al. (2003a) Effects of lateral confinement on order in spherical domain block copolymer thin films. Macromolecules, 36(18), 6831-6839. 

Now again, a state of inhomogeneity in polymers, so especially interesting in films and interfaces, occur when discontinuities are built into the main valence chains and networks. Block polymers are the classic embodiments of this. Many periodic distances separating domains in such alternating or rhymthic copolymers have been reported. These indicate existence of phases in laminar domains and, in other cases, of spherical domains.(51) Cases are shown experimentally for styrene/isoprene copolymers and also for styrene/butadiene.(52,53,54)... 

Dale Meier has been one of the firsts if not the first who presented a theory of domain formation in block copolymers39. In its original version39, Meier s theory was restricted to AB block copolymers and spherical domains. In a series of following papers40-45, 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. 

Leary and Williams have proposed for ABA block copolymers a model characterized by a simultaneous existence of three phases pure A, pure B and a mixed region. Their model, which postulated spherical domains in its first version50, has been extended to cylindrical and lamellar domains51,52. ... 

Styrene—methylmethacrylate Diblock Copolymer. Referring to Meier s (3) work, we expect that our model system consists of rather small spherical domains of PMMA blocks in a PS matrix (domain diameter around 500 A). The method of precipitation should point to the same conclusion. 

In another application electrospinning [189] of PS-fo-P4VP(PDP)i.o supra-molecules was used to produce internally structured fibers with diameters in the range of 200-400 nm. Due to the block copolymer sample selected, self-assembly resulted in spherical P4VP(PDP) domains with the well-known internal lamellar structure. After the PDP was extracted from the fibers using methanol, porous fibers were obtained [190]. With this method, the thickness of the fibers can be tuned by adjusting the spinning conditions, and the size and nature of the pores can be controlled by the choice of block copolymer and amount of amphiphile. 

In another report, a 50 nm thick poly(styrene-h-methylmethacrylate) block copolymer film with spherical domains was prepared on a sodium chloride monocrystal and coated by a thin layer of gold, replicating the domain pattern. Similar results were also obtained with poly(styrene-h-2-vinylpyridines) [113]. 

Hashimoto T., Fujimura M. and Kawai H., Domain-boundary structure of styrene-isoprene block copolymer films cast from solutions 5. molecular-weight dependence of spherical microdomains. Macromolecules 13 (1980) pp. 1660-1669. 

To explain the existence of three types of domain structures (spherical, rodlike, and lamellar) in SI, SIS, and ISI block copolymers cast from dilute solution, Kawai et al. have assumed the formation of micellar structures at a critical con-... 

Di-Block Copolymers with Spherical Domain Morphology. . . . 311... 

Crazing in Block Copolymers with Spherical Domains.316... 

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