Spinodal Dewetting of Thin Polymer Films

Xie, Rui; Karim, Alamgir; Douglas, Jack F.; Han, Charles C.; Weiß, Robert

doi:10.1103/physrevlett.81.1251

Cited by 599 publications

(635 citation statements)

References 24 publications

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“…As can be seen in Figure 2b) and 2c), both the radial profile and the dynamic TEM images capture well the evolution of the dewetting self-assembly process, which is attributed to a spinodal thin-film instability [35][36][37][38] . Spinodal thin-film instabilities are initiated by surface wave perturbations and importantly have correlated time and length scales.…”

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confidence: 75%

Real-Time Observation of Nanosecond Liquid-Phase Assembly of Nickel Nanoparticles via Pulsed-Laser Heating

et al. 2012

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Using the dynamic transmission electron microscope (DTEM), the dewetting of thin nickel films was monitored at nanometer spatial and nanosecond timescales to provide insight into the liquidphase assembly dynamics. Correlated time and length scales indicate that a spinodal instability drives the assembly process. Measured lifetimes of the liquid metal agree with finite-element simulations of the laser-irradiated film. These results can be used to design improved synthesis and assembly routes toward achieving advanced functional nanomaterials and devices. Keywords assembly dynamics, dynamic transmission electron microscopy, pulsed-laser heating, thin-film dewetting LetterThe synthesis and organization of functional nanomaterials via bottom-up self-and directed assembly represents a critical challenge for the future of nanoscience. Generating arrays of nanoparticles with controlled size and spatial distributions is key to this challenge, and processes that exploit morphological instabilities offer the potential to attain these fine-scale spatially correlated structures. There has been long-standing interest in the capillarity and surface tension effects on morphological evolution in various materials systems, dating back to the work of Plateau 1 and Rayleigh 2 . Recently, pulsed-laser-induced dewetting of two-dimensional films 3-9 , one-dimensional lines and rings [10][11][12][13] , and lithographically patterned nanostructures 14,15 has demonstrated that understanding and controlling thin-film and Rayleigh-Plateau instabilities improves the ability to create organized metallic nanoparticle ensembles. Assembled particles have also been shown to "jump" or eject from one substrate and transfer to another depending on the energetics and dynamics of various laser-melted nanostructures [16][17][18] . Heretofore, the as described in the Methods section, the laser spot has a Gaussian profile and thus the radial profile of each image also contains thermal and temporal information. Figure 2d) shows an image taken long after a laser pulse to show the resultant nanoparticle structure in the same field of view. The images in Figure 2 were filtered to remove noise and irrelevant intensity variations using a 3x3 median filter followed by a local brightness and contrast equalization filter using a Gaussian kernel with an rms width of 33 pixels in the x-and y-directions. The raw images are provided in the Supporting Information.Dynamic selected-area diffraction (SAD) patterns were recorded as a function of time to complement the dynamic imaging and estimate the nickel liquid lifetime. Figure 3a) shows a series of SAD patterns taken at various times relative to the specimen pump laser's interaction with the specimen (including as-deposited and post-laser-pulse diffraction patterns using a long exposure time). The simulated diffraction pattern for polycrystalline nickel is included in the long-exposure as-deposited diffraction pattern. The conventional diffraction pattern from the asdeposited film shows broad diffraction ri...

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confidence: 75%

Real-Time Observation of Nanosecond Liquid-Phase Assembly of Nickel Nanoparticles via Pulsed-Laser Heating

et al. 2012

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“…101 It is commonly admitted that nucleation occurs in the early stage of dewetting and spinodal dewetting is promoted for thin films. 101,102 On gold samples, the values of polar components (g + + g À ) were ten times lower than those of the apolar one (g LW ); hence, following Lee's idea, it indicated that gold surface exhibits a strong stabilizing force towards the film. The SEM images showed the beginning of the dewetting process through the heterogeneous nucleation (white spots) stopped before the growth of holes…”

Section: Discussionmentioning

confidence: 99%

Surface-induced assembly of sophorolipids

Peyre

Hamraoui

Faustini

et al. 2017

Phys. Chem. Chem. Phys.

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The surface self-assembly properties of acidic sophorolipids, a bolaform microbial glycolipids with pHresponsive properties in solution, were studied based on the chemical nature of the support and pH of the solution. Sophorolipids generally form micelles in water but formation of morphologies like platelets and twisted fibers depending on pH have also been reported. The surface self-assembly was achieved using dip-coating on three different substrates namely gold, silicon(111) and TiO 2 anatase. Deposition conditions (dip-coating withdrawal speed, relative humidity, temperature) were tested, and it was found that optimum self-assembly occurred at a withdrawal speed of 1 mm s À1 , T of 25 1C and relative humidity of 25%. The local structure of the sophorolipid films was characterized by Atomic Force Microscopy, while Scanning Electron Microscopy was used to characterize the spatial homogeneity. We also attempted to correlate dispersive, electron donor and electron attractor surface energy components, using Good-Van Oss's approach, and the behavior of sophorolipids. We found that when the surface energy is dominated by dispersive components, sophorolipids spontaneously assemble into entangled needles at all pH values (4, 6 and 11). However, when the surface energy is dominated by electronic components, pH has a strong influence on the surface self-assembly. We could discriminate three major organizations: homogeneous layer, isolated aggregates and a two-dimensional network similar to block copolymer surface self-assembly.

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“…ting structure have been extensively studied (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Here, we have investigated the dewetting of oleo-liquid film containing octyl p-methoxycinnamate and octylsilyl titanium dioxide particle having average diameter of 35 nm on glass surface.…”

Section: Resultsmentioning

confidence: 99%

“…Wave vector of the fastest growing fluctuation q M , is theoretically in inverse proportion to square root of interfacial tension (4,9). The characteristic length of the fastest growing fluctuation should thus increase as increasing the interfacial tension.…”

Section: Results Andmentioning

confidence: 99%

“…It proceeds following spinodal manner and the mechanism has been experimentally and theoretically investigated (2)(3)(4)(5)(6)(7)(8)(9)(10). The spinodal dewetting is a barrierless spontaneous instability resulting from the condition where the second derivative of the excess intermolecular free energy per unit area with respect to the local film thickness is negative.…”

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confidence: 99%

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