Symmetry plays a key role in the erasing of patterned surface features

Benzaquen, Michael; Ilton, Mark; Massa, Michael V.; Salez, Thomas; Fowler, Paul; Raphaël, Élie; Dalnoki-Veress, Kari

doi:10.1063/1.4927599

Cited by 12 publications

(23 citation statements)

References 56 publications

(72 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As it stands, however, the ability to generate subwavelength 1 or 2D patterns without the need for pulsed laser systems or immersion optics is highly attractive. Further, the CNT dewetting has already been applied to the device‐level fabrication of all‐semiconductor CNT transistor architectures, and the laser‐induced FLaSk approach has recently been employed in single dot exposures by Dalnoki‐Veress and coworkers as a means to generate controlled disturbances on polymer thin films to establish initial conditions for the study of smoothing/dewetting behavior …”

Section: Introductionmentioning

confidence: 99%

Thermocapillary approaches to the deliberate patterning of polymers

Singer

2017

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

The phenomenon of thermocapillarity, the response of fluids to thermal gradients due to thermal alteration of their surface tension, was first reported over a century ago. Since then, research has focused generally on either the fundamentals or mitigation of this effect during the processing of materials. Only in the past two decades has the deliberate use of thermocapillary forces for the patterning of polymers been actively pursued, either for the ordering of internal structure or the introduction of topographic features. This review seeks to highlight this work and to identify directions for further investigation. In particular, while thermocapillary forces are often inextricably bound to other mechanisms, there are emerging directions in the deliberate coupling of forces to improve the capabilities of each mechanism. Further, the applications of thermocapillary patterning to polymer-nanoparticle composites has recently provided another promising route to active architectures.

show abstract

Section: Introductionmentioning

confidence: 99%

Thermocapillary approaches to the deliberate patterning of polymers

Singer

2017

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

show abstract

“…The polystyrene (PS) films were then floated off the mica onto a deionized water bath (18.2 MΩ cm, Pall, USA), and transferred onto silicon (University Wafer, USA). Pores in the polystyrene film were created by a focused laser spike annealing setup [33][34][35], where a tightly focused laser (Coherent, Verdi V2, 532 nm) was used to locally heat the silicon wafer supporting the PS film. This heating had two effects.…”

mentioning

confidence: 99%

Direct Measurement of the Critical Pore Size in a Model Membrane

2016

Self Cite

View full text Add to dashboard Cite

We study pore nucleation in a model membrane system, a freestanding polymer film. Nucleated pores smaller than a critical size close, while pores larger than the critical size grow. Holes of varying size were purposefully prepared in liquid polymer films, and their evolution in time was monitored using optical and atomic force microscopy to extract a critical radius. The critical radius scales linearly with film thickness for a homopolymer film. The results agree with a simple model which takes into account the energy cost due to surface area at the edge of the pore. The energy cost at the edge of the pore is experimentally varied by using a lamellar-forming diblock copolymer membrane. The underlying molecular architecture causes increased frustration at the pore edge resulting in an enhanced cost of pore formation.Nucleation and growth occurs in a variety of physical systems where there is a phase transition. Crystallization of ice, the formation of micelles in solution, and the growth of diamonds from vitreous carbon are all systems where a nucleus can form and then either grow or shrink depending on its size [1]. In crystallization, for example, there is a trade-off between the volumetric free energy contribution which favors the crystalline phase, and the surface area dependent cost of the interfacial tension between the two phases which favors a single liquid phase [2]. By examining the free energy cost of creating a nucleated phase with radius r, the critical radius r c can be derived from classical nucleation theory. For a nucleus with r < r c , the nucleated phase is unstable to fluctuations, while for r > r c the nucleated phase is energetically favorable and the nucleus can grow. The same physics governs diverse phenomena including bubble nucleation of false vacuum states in inflationary cosmology [3], as well as many biologically important processes such as amyloid-beta protein aggregation [4,5], microtubule growth [6], and pore formation in cell membranes [7]. Membrane pores can be created by pathogenic bacteria to invade target cells [8], and play an important role in many biological processes such as mechanical force transduction [9] and water permeability of biological membranes [10]. In this letter we focus on pore formation in a membrane.For the nucleation of a pore in a membrane, there is a balance between two competing effects. First, there is an energy cost of having an interface between the membrane and its surrounding phase. Because the presence of a pore removes interface, this reduces the interfacial energy cost. Opposing this effect is the energetic cost of creating an edge around the perimeter of the pore. The stability and growth of pores depends on the relative contribution of interface reduction compared to the edge cost. The free energy cost of creating a pore in a membrane which has two surfaces with interfacial tension γ is given by [11] ∆G(r) = 2πrΓ − 2πr 2 γ,where Γ is the edge tension (or line tension) of the pore: the free energy cost per unit length of creating interface at t...

show abstract

“…The linearised one-dimensional lubrication equation then reads The relaxation of localised thin-film perturbations described by (4.4) was analysed in great detail by Salez et al (2012 a ), McGraw et al (2012), Bäumchen et al (2013), Backholm et al (2014), Benzaquen, Salez & Raphaël (2013), Benzaquen et al (2014, 2015) and Bertin et al (2020). They obtained the long-time asymptotic solution in terms of a moment expansion, which involves the similarity variable and similarity functions that can be determined analytically (Benzaquen et al 2013, 2014, 2015). The amplitudes appearing in (4.5) can be determined from the initial condition , by computing the moments …”

Section: Relaxation Of Viscous Thin-film Deformationsmentioning

confidence: 99%

“…Starting from experimentally obtained deformations as initial conditions, we then compare the evolution of the experimental profiles in the relaxation process to a numerical calculation using lubrication theory. Next, we use a general theoretical result of Benzaquen et al (2015) for the relaxation of thin-film deformations. From this we obtain scaling laws for the width broadening and amplitude decay during the relaxation process and compare with our experiments over a large range of parameters.…”

Section: Introductionmentioning

confidence: 99%