Segregation, block

Matson M.W. and Bates E.S., Unifying weak- and strong-segregation block copolymer theories. Macromolecules, 29, 1091, 1996. 

Application of amphiphilic block copolymers for nanoparticle formation has been developed by several research groups. R. Schrock et al. prepared nanoparticles in segregated block copolymers in the sohd state [39] A. Eisenberg et al. used ionomer block copolymers and prepared semiconductor particles (PdS, CdS) [40] M. Moller et al. studied gold colloidals in thin films of block copolymers [41]. M. Antonietti et al. studied noble metal nanoparticle stabilized in block copolymer micelles for the purpose of catalysis [36]. Initial studies were focused on the use of poly(styrene)-folock-poly(4-vinylpyridine) (PS-b-P4VP) copolymers prepared by anionic polymerization and its application for noble metal colloid formation and stabilization in solvents such as toluene, THF or cyclohexane (Fig. 6.4) [42]. 

Since many useful commercial polymers are composite in the sense of being blends, segregated block copolymers, filled and plasticized material it becomes especially interesting to be able to identify which component is moving, its spatial extent and possibly the composition of a region. 

For polymers, DT is found to be virtually independent of chain length and chain branching, but it is strongly dependent on polymer and solvent composition [84]. For random copolymers, DT varies linearly with monomer composition block copolymers display more complex behavior [111,214]. For segregated block copolymers like micelles, DT seems to be determined by the monomers located in the outer region (see Fig. 18). For particles, DT appears to be both composition and size dependent [215]. 

Fig. 3. Computer simulation results using a time-dependent Ginzburg-Landau approach, showing the microstructural evolution after a temperature jump from the lamellar phase to the hexagonal cylinder phase for a moderately asymmetric diblock copolymer. The time units are arbitrary. (Reprinted with permission from Polymer 39, S. Y. Qi and Z.-G. Zheng, Weakly segregated block copolymers Anisotropic fluctuations and kinetics of order-order and order-disorder transitions, 4639-4648, copyright 1998, with permission of Excerpta Medica Inc.)...

Other possible areas of application of the periodic surfaces, or of disordered relatives of these, include structure of superconductors in the intermediate state (Shal nikov 1941), sintering kinetics (Hench and Ulrich 1984), fluid flow through porous media (e.g., Zick and Homsy 1982), the topology of spacetime at the scale of Planck length (Wheeler 1957), the structure of the prolamellar body in certain plastics (Gunning 1965), certain phase-segregated block copolymers (Thomas et al. 1986 Anderson and Thomas 1988)) semiconductor-... 

Forster, S. Zisenis. M. Wenz. E. Antonietti, M. Micellization of strongly segregated block copolymers. J. Chem. Phys. 1996, 104. 9956. 

Surface segregated block copolymers have been fabricated with responsive segments that allow them upon surface segregation to vary the surface behavior as a function of the external stimuli. Examples of responsive segments incorporated in the block copolymer design include poly(aciylic acid) or synthetic polypeptides... 

Matsen MW, Bates FS (1996) Unifying Weak-and Strong-segregation Block Copolymer Theories. Macromolecules 29 1091-1098 and Matsen MW, Bates FS (1997) Block Copolymer Microstructures in the Intermediate-segregation Regime. J Chem Phys 106 2436-2448. 

Toughening of a semicrystalline polymer by a phase segregated block copolymer introduces several levels of complexity, as shown in an example of a nylon 66 toughened with a Kraton... 

---