Dewetting Induced by Density Fluctuations

Wensink, K.D.F.; Jérôme, Bruno

doi:10.1021/la015611z

Cited by 57 publications

(76 citation statements)

References 31 publications

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“…On the other hand, Chung et al [20] have recently shown that the phase separation in thin films of SAN and dPMMA (d ¼ 550 nm) drove the dewetting and the capillary fluctuations failed to explain the dewetting. Liao et al [15] have experimentally demonstrated that the composition fluctuation mechanism [21][22][23][24] induced the dewetting in thermodynamically stable ultrathin blend films of SAN and dPMMA in one phase region. Thus, the dewetting mechanism in blend thin films is still a controversial problem.…”

Section: Introductionmentioning

confidence: 99%

Composition fluctuations before dewetting in polystyrene/poly(vinyl methyl ether) blend thin films

Ogawa

Kanaya

Nshida

et al. 2008

Polymer

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a b s t r a c tWe report structural development in blend thin films of deuterated polystyrene (dPS) and poly(vinyl methyl ether) (PVME) below w200 nm in two phase region during the incubation period before dewetting using neutron reflectivity (NR) and atomic force microscopy (AFM). As was predicted by the former optical microscope (OM) and small-angle light scattering (LS) measurements on blend thin films of protonated PS and PVME [Ogawa H, Kanaya T, Nishida K, Matsuba G. Polymer 2008;40:254-62.], the NR results clearly showed that the tri-layer structure consisting of the surface PVME layer, the middle blend layer and the bottom PVME layer was formed in the one phase region. After the temperature jump into the two phase region, it was found that the phase separation of the middle blend layer proceeded in the depth direction during the incubation period before dewetting, suggesting that the dewetting was induced by the composition fluctuations during the incubation period.

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Section: Introductionmentioning

confidence: 99%

Composition fluctuations before dewetting in polystyrene/poly(vinyl methyl ether) blend thin films

Ogawa

Kanaya

Nshida

et al. 2008

Polymer

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“…To investigate the correlation of the dewetted holes along the film surface, fast Fourier transition (FFT) was performed by taking There is a peak at q = 0.0044 nm −1 , corresponding to the periodic structures with size of 1400 nm. The result makes it clear that the holes are correlated with each other, which is a typical symbol of spinodal dewetting or dewetting by means of composition fluctuation [27][28][29].…”

Section: Resultsmentioning

confidence: 91%

Stability and structure evolution in PMMA/SAN bilayer films upon solvent annealing

et al. 2016

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The stability of bilayer polymer films upon solvent annealing has been investigated with the help of atomic force microscopy (AFM) by taking PMMA [poly(methyl methacrylate), the upper layer] and SAN [poly(styrene-ran-acrylonitrile), the bottom layer] system as an example. Our results indicate that the stability and structure evolution depend crucially on the selectivity of the adopted annealing solvents. In the vapor of acetic acid (HAc, the selective solvent for PMMA), the upper PMMA layer dewets on the stable bottom SAN layer; upon annealing in 1, 2-dichlorobenzene (OBD, the selective solvent for SAN) vapor, the bilayer film remains stable because it is very hard for OBD molecules to penetrate and cross the upper PMMA layer. When dimethylformamide (exhibiting much higher solubility for SAN than PMMA) is used to anneal the specimen, the solvent molecules swell and cross the upper PMMA layer and enrich in the bottom SAN layer. As a result, SAN layer dewets the substrate, producing some SAN droplets while the upper PMMA is Bcarried^by the movement of SAN. This is the reason for the rupture of the upper film and the formation of BSAN droplets covered by PMMA islands.K eywords Dewetting . Bilayer . Solvent annealing . AFM . PMMA/SAN

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“…This is the case introduced in [3]. For Γ 0 > 0, the film stability will be enhanced, as discussed in [5,6].…”

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confidence: 89%

“…The process by which a thin film may become instable and break up into a pattern of holes and droplets, has been attributed to two different mechanisms; nucleation and spinodal dewetting [2]. Recently, Wensink and Jérôme [3] proposed an alternative mechanism that resembles spinodal dewetting. Their idea was that confinement and restructuring of the molecules in the film creates density variations that in turn change the sign of the effective film-substrate interactions, thus leading to the dewetting of a film expected to be stable.…”

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confidence: 99%

Marangoni effect from density variations in apolar ultrathin films

2006

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Recently it was demonstrated that the presence of density variations in thin films can induce interactions that cause destabilization and rupture of thin films. In apolar films the surface tension is also dependent on the film density, so that a lateral variation in film density creates a surface tension gradient, thus producing a Marangoni effect. We include this effect in the hydrodynamic equation governing the evolution of the film profile and perform an analysis of the stability of the film. In particular, inclusion of the Marangoni effect causes the characteristic length scale of the initial flat film instabilities to scale with the film thickness h0 to a lower power (down to n = 0.5) than without this effect.

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Dewetting Induced by Density Fluctuations

Cited by 57 publications

References 31 publications

Composition fluctuations before dewetting in polystyrene/poly(vinyl methyl ether) blend thin films

Composition fluctuations before dewetting in polystyrene/poly(vinyl methyl ether) blend thin films

Stability and structure evolution in PMMA/SAN bilayer films upon solvent annealing

Marangoni effect from density variations in apolar ultrathin films

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