Ordered block copolymers

Shi A C, Noolandi J and Desai R C 1996 Theory of anisotropic fluctuations in ordered block copolymer phases Macromolecules 29 6487... 

Measurements of diffusion of tracer polymers in ordered block copolymer fluids is another potentially informative activity, since molecular diffusion is one of the most basic dynamic characteristics of a molecule. Balsara, et al. have measured the retardation of diffusion due to ordering in the diffusion of polystyrene tracer homopolymers in polystyrene-polyisoprene matrices of various domain sizes [167]. Measurement of the tracer diffusion of block copolymer molecules will also be important. Several interesting issues are directly addressable via measurements... 

Zhen-Gang Wang, Morphology, Fluctuation, Metastability and Kinetics in Ordered Block Copolymers... 

This work was important for several reasons in addition to the original demonstration of the methodology for generating porous films from ordered block copolymer precursors. Demonstrating porosity necessitates more than just microscopy. The complementary N2 adsorption, gravimetric, spectro-... 

In this review I have attempted to give a comprehensive overview of the published work on nanoporous materials prepared from ordered block copolymers. Given the numerous successful demonstrations of the block copolymer strategy in the design, synthesis, and applications of nanoporous materials, this methodology holds a great deal of promise for the bottom-up en-... 

In the second area, improvements to the thermal and mechanical stability of nanoporous materials from ordered block copolymers should be targeted. To expand the application base for these materials, high temperature stability is a key requirement. For example, in templating applications that require elevated processing temperatures in either thin films or monolithic materials... 

As I hope this review conveys, the design, synthesis, development, and application of nanoporous polymers from ordered block copolymer precursors is an exciting research arena with both fundamental and practical consequences in the fields of block copolymer science and technology. 

This chapter is concerned with experiments and theory for semidilute and concentrated block copolymer solutions.The focus is on the thermodynamics, i.e. the phase behaviour of both micellar solutions and non-micellar (e.g. swollen lamellar) phases. The chapter is organized very simply Section 4.2 contains a general account of gelation in block copolymer solutions. Section 4.3 is concerned with the solution phase behaviour of poly(oxyethylene)-containing diblocks and tri-blocks. The phase behaviour of styrenic block copolymers in selective solvents is discussed in Section 4.4. Section 4.5 is then concerned with theories for ordered block copolymer solutions, including both non-micellar phases in semidilute solutions and micellar gels. There has been little work on the dynamics of semidilute and concentrated block copolymer solutions, and this is reflected by the limited discussion of this subject in this chapter. 

The effect of adding homopolymer to ordered block copolymer melts was interpreted by considering how homopolymer is distributed within the microstructure (Matsen 19956). Within the A-rich domains of a microslructure, the A blocks tend to segregate to the interfaces, whereas homopolymer A is preferentially located in the domain centre due to tension in the A blocks. This is countered by the entropy of mixing which favours a more uniform distribution of homopolymer. To allow homopolymer near the interface, a phase transition may occur to a microstructure where the interface is less curved towards the A-rich domains (this is the reverse of the process shown in Fig. 6.9). Even without such a phase transition, increasing homopolymer content leads to an increasing... 

---