Thin polymer blends

Phase Separation in Thin Polymer-Blend Films. 120... 

Micrometer sized surface structures in thin polymer blend films are detectable with optical techniques as well and... 

Xue, L., Zhang, J., Han, Y. Phase separation induced ordered patterns in thin polymer blend films. Prog. Polymer Sci. (Oxf) 37(4), 564-594 (2012)... 

Gutmann, J.S., Muller-Buschbaum, P., Schubert, D.W., Stribeck, N., Stamm, M. Influence of the blend compatibility on the morphology of thin polymer blend films. J. Macromol. Sci. Phys. 38 (1999)... 

Morita, H., Kawakatsu, T, and Doi, M. Dynamic densily functional study on the structure of thin polymer blend films with a free surface. Macromolecules, 34, KTll- i (2001). 

Ferreiro, V., Douglas, J.F., Warren, J., Karim, A. Growth pulsations in symmetric dendritic crystallization in thin polymer blend films. Phys. Rev. E 65, 51606 (2002)... 

Phase separation can emerge spontaneously in thin films of polymer blend, and it is this thermodynamically driven phase-separation process that produces the patterning of thin polymer blend films. It can be induced by several parameters, each with critical values, including (i) the ratio between the components [10,22] (ii) the demixing temperature [12] and (iii) the chemical nature of the solvent. 

The phase separation of thin polymer blend films can be also driven by substrate effects, including the effects of (i) the substrate composition (ii) the substrate functionalization and/or (iii) the substrate structures. In particular, the self-assembly of polymer molecules on a substrate can be controlled by selectively modifying the chemistry of the substrate surface and/or the polymers to create patterned polymer films with tailored length scales. 

Many previous studies have considered the influence of confinement on the equilibrium phase separation temperature of thin films [50,51], and of spatial dimensionality on the kinetics of spinodal decomposition [52]. The latter study involved a combination of these factors, whereby an examination was made of the effect of finite film thickness on the kinetics of spinodal decomposition over a film thickness range where transition occurred from three-dimensional bulk-like to near two-dimensional kinetics. In particular, the 1000 A thin polymer blend films of PS and polybutadiene on a silicon substrate were found to be sufficiently thick to exhibit phase-separation kinetics similar to those of bulk blends. The thinner film (L w 200 A) exhibited a different phase-separation kinetics, however [47]. 

Currently, AFM, neutron reflection (NR) spectroscopy and SIMS are used to examine phase separation in symmetrically segregating thin polymer blend films (ca. 1000 A). Phase separation in the film leads to undulations of the liquid-air interface, provided that the film is sufficiently thin to suppress any surface-directed spinodal decomposition waves. Flattened droplets are formed at a very... 

Gutmann JS, Miiller-Buschbaum P, WoDcenhauer M, Hermsdorf N, Stamm M. X-ray and neutron grazing incidence scattering study of a ternary ultra-thin polymer blend film. J Macromol Sci B 2005 43 207-217. 

Muller-Buschbaum P, Gutmann JS, Stamm M. Influence of blend composition on phase separation and dewetting of thin polymer blend films. Macromolecules 2000 33 4886-4895. 

Polymer layers can exhibit significantly improved performances if they possess a multicomponent phase-separated morphology. Kietzke et al. [55] presented two approaches to control the dimensions of phase separation in thin polymer-blend layers based on polymer nanospheres prepared by the miniemulsion process. In the first approach, helerophase solid layers are prepared from an aqueous dispersion containing nanoparticles of two polymers, whereas in the second approach, both polymers are already contained in each individual nanoparticle. In both cases, the upper limit for the dimension of phase separation is determined by the size of the individual nanoparticles, which can be adjusted down to a few tens of nanometres. They also demonstrated that the efficiencies of solar cells using... 

Tang H, Szleifer I, Kumar SK. Critical-temperature shifts in thin polymer blend films. J Chem Phys 1994 100 5367-71. 

Miiller-Buschbaum P, Stamm M. Film thickness dependence of the domain size in weakly incompatible thin polymer blend films. Colloid Polym Sci 2001 279 376-81. 

Gutmann JS, MiiUer-Buschbaum P, Stamm M. Fihn-thickness dependence of stracture formation in ultra-thin polymer blend films. Appl Phys Mater Sci Process 2002 74 8463-5. 

Karim A, Slawecki TM, Kumar SK, Douglas JF, Satija SK, Han CC, et al. Phase-separation-induced surface patterns in thin polymer blend films. Macromolecules 1998 31 857-62. 

Geoghegan M, Jones RAL, Payne RS, SakeUariou P, Clough AS, Penfold J. Lamellar structure in a thin polymer blend film. Polymer 1994 35 2019-27. 

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