Nonlinear instabilities and pathways of rupture in thin liquid bilayers

Bandyopadhyay, Dipankar; Sharma, Ashutosh

doi:10.1063/1.2221679

Cited by 51 publications

(111 citation statements)

References 44 publications

Supporting

Mentioning

110

Contrasting

Order By: Relevance

“…As compared to single-layer films, the complexity of the free energy and dynamics in bi-layer systems is significantly higher [19][20][21][22] then the single-layer because of the increase in the pairs of interfaces (three in bi-layers vs one in single-layer) and the possibility for deformation to occur via bending and squeezing modes, as shown in Fig. 1(a), which are absent in single-layer films.…”

Section: Introductionmentioning

confidence: 93%

Morphology transitions in bilayer spinodal dewetting systems

2012

View full text Add to dashboard Cite

In spontaneous pattern formation by spinodal dewetting, attractive intermolecular forces overcome surface tension and cause an ultrathin liquid film on a low energy substrate to produce ordered structures. Spinodal dewetting in single-layer film on a substrate, is usually manifested by an early stage surface deformation and a highly non-linear ripening stage that results in characteristic morphologies, typically bicontinuous-or hole-like states. Here we have experimentally constructed the dewetting morphology phase diagrams for a bi-layer (Ag, Co) liquid film system on SiO 2 . Nanosecond pulsed laser melting was used to initiate and foster the dewetting as a function of film thickness and arrangement. The early stage ripening morphology was observed by scanning electron microscopy from which the phase diagrams were constructed. Unlike single-layer films, which only show one morphology transition between the bicontinuous to hole states as the film thickness is increased, the bi-layer system can have multiple transitions. We have utilized the thickness-dependent free energy curvature approach (Sharma and Khanna, Phys. Rev. Lett. 81 p3463 1998) to analyze the phase diagram. The location of the multiple transitions cannot be predicted from the curvature minima, as was the case for single-layer films. Nevertheless, despite the complexity from multiple interacting forces and different surface deformation mode in bi-layer systems , the phase diagram can be completely generated by knowledge of the free energy curvature of the respective single-layer films. These results can permit improved modeling of the non-linear dynamics in naturally driven self-organized phenomenon and help design nanomaterials for advanced applications.

show abstract

Section: Introductionmentioning

confidence: 93%

Morphology transitions in bilayer spinodal dewetting systems

2012

View full text Add to dashboard Cite

show abstract

“…Figure 1 shows the schematic diagram of the bilayers on top of (a) physically heterogeneous and (b) chemically patterned substrate. Detailed theoretical studies into the different features of short and long time instabilities of ultra-thin bilayers have also been recently conducted (Danov et al 1998a, b;Paunov et al 1998;Bandyopadhyay et al 2005Bandyopadhyay and Sharma 2006, 2010Pototsky et al 2004Pototsky et al , 2005Pototsky et al , 2006Nepomnyashchy and Simanovskii 2006a, b, 2007, 2009aMerkt et al 2005;Kumar and Matar 2004;Matar et al 2005;Golovin 2005, 2007).…”

Section: Introductionmentioning

confidence: 97%

Self-Organized Micropatterning of Thin Viscous Bilayers Under Microgravity

Bandyopadhyay

Sharma

Joo

et al. 2010

Microgravity Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Self-organized ordered microstructure formation under the action of van der Waals forces is studied in thin (<100 nm) viscous bilayers through nonlinear simulations. For ultra-thin (<100 nm) films, intermolecular forces dominate over the other body forces, thus simulating microgravity conditions needed for fabrication of non-distorted ordered patterns. In particular, we concentrate upon a special type of bilayer in which only the lower layer is unstable and the upper layer is unconditionally stable to fabricate embedded microstructures. The patterns on the films are fabricated by employing either a topographically or chemically patterned solid substrate to control the spatial strength of the intermolecular force. The conditions are identified to fabricate a number of interesting interfacial morphologies such as: (a) embedded microchannels of herringbone shape, (b) encapsulated and embedded droplets of spatially varying shape, and (c) perforated membranes. Our study shows that this methodology can not only lead to ordered patterns, but is also capable of pattern replication because the patterns formed at the embedded liquid-liquid interface are also transferred to the free and stable liquid-air interface.

show abstract

“…However, some recent studies [36][37][38][39][40][41][42][43][44] have indicated that kinetic forces also greatly inuence the instability of the thin polymer bilayer, as a result the instability could become a kinetically controlled one. Bandyopadhyay et al 36 have shown that a marked decrease in the viscosity of the upper layer increases the rate of deformation of the upper interface, causing the instability shiing back to the upper interface. Our previous paper 43 has reported that the interfacial slip effect can greatly inuence the instability mode of the thin polymer bilayer.…”

Section: Introductionmentioning

confidence: 99%

Dewetting of a pre-patterned thin polymer bilayer: influence of the instability mode

Chen

Zou

2017

RSC Adv.

View full text Add to dashboard Cite

In this paper, the influence of film thickness on the layer instability mode of a thin polymer bilayer (poly(methylmethacrylate) (PMMA)/polystyrene (PS)/Si substrate) has been investigated. The experimental results show that kinetic forces can greatly influence the instability process of the thin polymer bilayer. In the case of PS-2.4K (M w-PS ¼ 2.4 kg mol ), only the PMMA layer ruptures on the PS layer and the dewetting process is a thermodynamically controlled one. Besides, the influence of the instability mode on the template-assisted dewetting process of the thin polymer bilayer also was studied. After annealing the pre-patterned bilayer, in the case of the kinetically controlled dewetting, the PMMA film bends to conform to the buried PS-PMMA interface and concave half cylinder grooves form during the dewetting process; however, in the case of the thermodynamically controlled dewetting, PMMA chains move to the top of cylinder stripes and obvious trenches are found after PMMA chains are etched. This proposes a simple method to obtain different surface structures by changing the instability mode of the thin polymer bilayer.

show abstract

Nonlinear instabilities and pathways of rupture in thin liquid bilayers

Cited by 51 publications

References 44 publications

Morphology transitions in bilayer spinodal dewetting systems

Morphology transitions in bilayer spinodal dewetting systems

Self-Organized Micropatterning of Thin Viscous Bilayers Under Microgravity

Dewetting of a pre-patterned thin polymer bilayer: influence of the instability mode

Contact Info

Product

Resources

About