Thin films homopolymer-blend

SURFACE MORPHOLOGIES IN HOMOPOLYMER-BLEND THIN FILMS... 

As depicted in part 3, independently of the mechanism employed (solvent evaporation, decrease of the temperature, from surface instabilities, convection, etc.) induction of phase separation is a prerequisite to obtain structured interfaces. Assuming that phase separation occurs, there are different aspects to the preparation of the films that require special attention in the case of homopolymer-blend thin films. These include, among others, film thickness, thermal or solvent annealing, the solvent employed to prepare the films, or the characteristics of the substrate used to form the thin film. 

Herein, the parameters influencing the pattern obtained will be discussed. Parts 5 to 7 will extend the study to the formation of thin films of blends containing BCs. First we will describe the main features of BCs in thin films and later we will distinguish between homopolymer/BC blends and BC/BC blends thin films, which will be analyzed separately in parts 6 and 7 respectively. Finally, part 8 will provide information on the state of the art in the preparation of more sophisticated interfaces and their potential uses, illustrated with recent selected examples. 

Another example of favorable synergistic effects in ionomer/homopolymer blends is evident from a study of the tensile properties of blends of an SPS ionomer with PS. Over most of the composition range these two polymers are incompatible. For small additions of the SPS ionomer to PS, TEM studies of cast thin films show that... 

Microdomains of block copolymer/ homopolymer blends 25-A-diameter Pd clusters Metal-ion precursors, introduced into cast thin films of polymer microdomains, are reduced by high pressure hydrogen 60,61... 

This chapter is organized as follows. Section 6.2 is concerned with experiments on binary block copolymer/homopolymer blends, Section 6.3 deals with experiments on ternary blends containing a block copolymer and in Section 6.4 experiments on binary blends of block copolymers are reviewed. Theory for the corresponding type of blend is discussed successively in Sections 6.5 to 6.7. Finally, experiments on thin films are discussed in Section 6.8, separately from the work on bulk blends, in keeping with earlier chapters. 

Thin films of block copolymer/homopolymer blends... 

Thin films of blends of block copolymer with two homopolymers... 

Fig. 6.52 Interfarial excess in thin films of blends of a dPS-P2VP diblock (A PS = 391, jVP2Vp = 68) with PS homopolymer (NK = 6440) (Dai et al. 1992). Since the homopolymer is much longer than the diblock, the diblock forms a dry brush. The circles are the results from forward recoil spectrometry, the lines correspond to theoretical calculations. The dashed line was computed using the theory of Leibler (1988), and the solid line is from the self-consistent mean field calculation of Shull and Kramer (1990).

Thin films of pure iPP and PB-1 homopolymers and iPP/HOCP, PB-l/HOCP blends, when observed under the optical polarizing microscope during the isothermal... 

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