Block copolymers films

Cakmak M. and Wang M.D., Structure development in the tubular blown film of PP/EPDM thermoplastic elastomer, Antec 89, 47th Annual Tech. Conference of SPE, New York, May 1, 1989, 1756. Hashimoto T., Todo A., Itoi H., and Kawai H. Domain boundary structure of styrene-isoprene block copolymer films cast from solution. 2. Quantitative estimation of the interfacial thickness of lamellar microphase systems. Macromolecules, 10, 377, 1977. 

Spatz J.P., Moessmer S., Hartmann C., MoellerM., Herzog T., KriegerM., Boyen H-G., Ziemann P., and Kabius B. Ordered deposition of inorganic clusters from micellar block copolymer films, Langmuir, 16, 407, 2000. 

Segahnan, R.A., Schaefer, KJi., Fredrickson, G.H., Kramer, E.J., and Magonov, S.N., Topographic templat-ing of islands and holes in highly as3munetric block copolymer films. Macromolecules, 36,4498, 2003. 

Here, we have demonstrated that it is possible to arrange successfully polystyrene microspheres with a diameter of 20 nm on each island (P4VP domain) of a PS-b- P4VP block copolymer film using hydrogen bonds. A 50 nm-large microsphere was rarely adsorbed to the PS-b-P4VP film. Since the present technique does not require an... 

Nanoscale Morphological Change of PS-b-P4VP Block Copolymer Films Induced by Site-Selective Doping of a Photoactive Chromophore... 

Machida, S., Nakata, H., Yamada, K and Itaya, A. (2002) Position-selective adsorption of fimctional nanopartides on block copolymer films. Prepr. lUPAC Polym. Confi p. 443. 

The use of lightly crosslinked polymers did result in hydrophilic surfaces (contact angle 50°, c-PI, 0.2 M PhTD). However, the surfaces displayed severe cracking after 5 days. Although qualitatively they appeared to remain hydrophilic, reliable contact angle measurements on these surfaces were impossible. Also, the use of a styrene-butadiene-styrene triblock copolymer thermoplastic elastomer did not show improved permanence of the hydrophilicity over other polydienes treated with PhTD. The block copolymer film was cast from toluene, and transmission electron microscopy showed that the continuous phase was the polybutadiene portion of the copolymer. Both polystyrene and polybutadiene domains are present at the surface. This would probably limit the maximum hydrophilicity obtainable since the RTD reagents are not expected to modify the polystyrene domains. 

In 2004, Olayo-Valles et al. described a related dry-etch processing of self-assembled block copolymer films to generate porous materials for use as magnetic material templates [50]. These authors employed thin films of... 

Abstract This article is a review of the chemical and physical nature of patternable block copolymers and their use as templates for functional nanostructures. The patternability of block copolymers, that is, the ability to make complex, arbitrarily shaped submicron structures in block copolymer films, results from both their ability to self-assemble into microdomains, the bottom-up approach, and the manipulation of these patterns by a variety of physical and chemical means including top-down lithographic techniques. Procedures for achieving long-range control of microdomain pattern orientation as well... 

A number of researchers have used surface energy libraries to examine the self-assembly of block copolymer species in thin films. It is well known that substrate-block interactions can govern the orientation, wetting symmetry and even the pattern motif of self-assembled domains in block copolymer films [29]. A simple illustration of these effects in diblock copolymer films is shown schematically in Fig. 6. However, for most block copolymer systems the exact surface energy conditions needed to control these effects are unknown, and for many applications of self-assembly (e.g., nanolithography) such control is essential. 

Smith AP, Douglas JF, Meredith JC, Amis EJ, Karim A (2001) Combinatorial study of surface pattern formation in thin block copolymer films. Phys Rev Lett 87 015503... 

The formation of a patterned surface through selective segregation of nanoparticles onto one domain of a block copolymer film can be used to produce complex 2-D nanoparticle arrays in a controlled fashion. However, the resulting... 

Figure 6.7 Illustration of multipoint hydrogen bonding based self-assembly (a) hydrogen bond formation between barbituric acid functionalized gold nanoparticles and Hamilton receptor functionalized block copolymers and (b) selective deposition of nanoparticles on a microphase-separated block copolymer film. Reprinted with permission fi om Binder et al. (2005). Copyright 2005 American Chemical Society.

Thin films of block copolymer melts, and block copolymers adsorbed at the liquid-liquid interface, have been investigated using specular reflectivity (largely neutron reflectivity due to the ability to vary the scattering contrast). Off-specular reflection is, in principle, a powerful method for determining in-plane structure in block copolymer films but is not yet widely used. 

Fig. 2.54 Neutron reflectivity profile for a symmetric PS-dPMMA diblock (Mw 30 kg moP1) as a function of incident wavevector (Russell 1990). The inset shows the scattering length density (b/V, the neutron scattering length per unit volume) profile normal to the film surface that was used to calculate the reflectivity profile shown as the solid line, This is typical of a block copolymer film containing a multilayer stack, with lamellae parallel to the surface.

Fig. 2.56 Beating of Kiessig fringes observed using X-ray reflectivity from a PVP PS-PVP tri block copolymer film (fes = 0.48, Mv = 120 kg mol ) with two discrete thicknesses of 1935 and 2229 A (de Jeu et al. 1993). The difference in height results from island and hole formation at the free surface, and is equal to the bulk domain spacing.

The formation of islands at the surface of lamellar block copolymer films has been studied in some detail using AFM by Coulon and co-workers (Ausserre et al. 1993 Coulon et al. 1993 Maaloum et al. 1992). The edge profile was investi-... 

In this chapter, structure formation in semicrystalline diblocks containing PE, PEO and other crystalline blocks is discussed in Section 5.2. Section 5.3 is concerned with theories for the equilibrium crystallization of block copolymers, whilst Section 5.4 summarizes recent experimental work on the kinetics of crystallization. There have been few studies of crystallization in thin block copolymer films, and consequently Section 5.5 is correspondingly short. Finally, structure formation in glassy diblocks is considered in Section 5,6. 

The differences in the master curves for log Ep(t) vs. log t obtained from Kraton 102 specimens cast from benzene, cyclohexane, and tetra-hydrofuran solutions may be caused by differences in the composition or the morphology of the phases. Beecher et al. (2) have emphasized the role of solvent in determining the phase structure of cast block copolymer films. At 25°C the solubility parameters for the polymers (3) and solvents (I) are Material Solubility Parameter... 

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

Olszowka V, Tsarkova L, Boker A (2009) 3-Dimensional control over lamella orientation and order in thick block copolymer films. Soft Matter 5(4) 812—819... 

---