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Schott M, Repetto L, Savio RL, Firpo G, Angeli E, Valbusa U. Identification of the seeding mechanism in the spinodal instability of dewetting liquids. J Colloid Interface Sci 2022; 632:65-73. [DOI: 10.1016/j.jcis.2022.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/03/2022] [Accepted: 11/06/2022] [Indexed: 11/13/2022]
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2
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Zitz S, Scagliarini A, Harting J. Lattice Boltzmann simulations of stochastic thin film dewetting. Phys Rev E 2021; 104:034801. [PMID: 34654097 DOI: 10.1103/physreve.104.034801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 08/11/2021] [Indexed: 11/07/2022]
Abstract
We study numerically the effect of thermal fluctuations and of variable fluid-substrate interactions on the spontaneous dewetting of thin liquid films. To this aim, we use a recently developed lattice Boltzmann method for thin liquid film flows, equipped with a properly devised stochastic term. While it is known that thermal fluctuations yield shorter rupture times, we show that this is a general feature of hydrophilic substrates, irrespective of the contact angle θ. The ratio between deterministic and stochastic rupture times, though, decreases with θ. Finally, we discuss the case of fluctuating thin film dewetting on chemically patterned substrates and its dependence on the form of the wettability gradients.
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Affiliation(s)
- S Zitz
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Strasse 248, 90429 Nürnberg, Germany.,Department of Chemical and Biological Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fürther Straße 248, 90429 Nürnberg, Germany
| | - A Scagliarini
- Institute for Applied Mathematics "M. Picone" (IAC), Consiglio Nazionale delle Ricerche (CNR), Via dei Taurini 19, 00185 Rome, Italy.,INFN, sezione Roma "Tor Vergata", via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - J Harting
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Strasse 248, 90429 Nürnberg, Germany.,Department of Chemical and Biological Engineering and Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fürther Straße 248, 90429 Nürnberg, Germany
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Diez JA, González AG, Garfinkel DA, Rack PD, McKeown JT, Kondic L. Simultaneous Decomposition and Dewetting of Nanoscale Alloys: A Comparison of Experiment and Theory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:2575-2585. [PMID: 33587633 DOI: 10.1021/acs.langmuir.0c02964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We consider the coupled process of phase separation and dewetting of metal alloys of nanoscale thickness deposited on solid substrates. The experiments involve applying nanosecond laser pulses that melt the Ag40Ni60 alloy films in two setups: either on thin supporting membranes or on bulk substrates. These two setups allow for extracting both temporal and spatial scales on which the considered processes occur. The theoretical model involves a longwave version of the Cahn-Hilliard formulation used to describe spinodal decomposition, coupled with an asymptotically consistent longwave-based description of dewetting that occurs due to destabilizing interactions between the alloy and the substrate, modeled using the disjoining pressure approach. Careful modeling, combined with linear stability analysis and fully nonlinear simulations, leads to results consistent with the experiments. In particular, we find that the two instability mechanisms occur concurrently, with the phase separation occurring faster and on shorter temporal scales. The modeling results show a strong influence of the temperature dependence of relevant material properties, implying that such a dependence is crucial for the understanding of the experimental findings. The agreement between theory and experiment suggests the utility of the proposed theoretical approach in helping to develop further experiments directed toward formation of metallic alloy nanoparticles of desired properties.
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Affiliation(s)
- Javier A Diez
- CIFICEN-CONICET-CICPBA, Instituto de Física Arroyo Seco, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, 7000 Tandil, Argentina
| | - Alejandro G González
- CIFICEN-CONICET-CICPBA, Instituto de Física Arroyo Seco, Universidad Nacional del Centro de la Provincia de Buenos Aires, Pinto 399, 7000 Tandil, Argentina
| | - David A Garfinkel
- Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Philip D Rack
- Department of Materials Science & Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Joseph T McKeown
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Lou Kondic
- Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102, United States
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Ruffino F, Grimaldi MG. Nanostructuration of Thin Metal Films by Pulsed Laser Irradiations: A Review. NANOMATERIALS 2019; 9:nano9081133. [PMID: 31390842 PMCID: PMC6723593 DOI: 10.3390/nano9081133] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 11/16/2022]
Abstract
Metal nanostructures are, nowadays, extensively used in applications such as catalysis, electronics, sensing, optoelectronics and others. These applications require the possibility to design and fabricate metal nanostructures directly on functional substrates, with specifically controlled shapes, sizes, structures and reduced costs. A promising route towards the controlled fabrication of surface-supported metal nanostructures is the processing of substrate-deposited thin metal films by fast and ultrafast pulsed lasers. In fact, the processes occurring for laser-irradiated metal films (melting, ablation, deformation) can be exploited and controlled on the nanoscale to produce metal nanostructures with the desired shape, size, and surface order. The present paper aims to overview the results concerning the use of fast and ultrafast laser-based fabrication methodologies to obtain metal nanostructures on surfaces from the processing of deposited metal films. The paper aims to focus on the correlation between the process parameter, physical parameters and the morphological/structural properties of the obtained nanostructures. We begin with a review of the basic concepts on the laser-metal films interaction to clarify the main laser, metal film, and substrate parameters governing the metal film evolution under the laser irradiation. The review then aims to provide a comprehensive schematization of some notable classes of metal nanostructures which can be fabricated and establishes general frameworks connecting the processes parameters to the characteristics of the nanostructures. To simplify the discussion, the laser types under considerations are classified into three classes on the basis of the range of the pulse duration: nanosecond-, picosecond-, femtosecond-pulsed lasers. These lasers induce different structuring mechanisms for an irradiated metal film. By discussing these mechanisms, the basic formation processes of micro- and nano-structures is illustrated and justified. A short discussion on the notable applications for the produced metal nanostructures is carried out so as to outline the strengths of the laser-based fabrication processes. Finally, the review shows the innovative contributions that can be proposed in this research field by illustrating the challenges and perspectives.
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Affiliation(s)
- Francesco Ruffino
- Dipartimento di Fisica e Astronomia "Ettore Majorana"-Università di Catania and MATIS CNR-IMM, via S. Sofia 64, 95123 Catania, Italy.
| | - Maria Grazia Grimaldi
- Dipartimento di Fisica e Astronomia "Ettore Majorana"-Università di Catania and MATIS CNR-IMM, via S. Sofia 64, 95123 Catania, Italy
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Zhang Y, Sprittles JE, Lockerby DA. Molecular simulation of thin liquid films: Thermal fluctuations and instability. Phys Rev E 2019; 100:023108. [PMID: 31574687 DOI: 10.1103/physreve.100.023108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Indexed: 06/10/2023]
Abstract
The instability of a thin liquid film on a solid surface is studied both by molecular dynamics simulations (MD) and a stochastic thin-film equation (STF), which models thermal fluctuations with white noise. A linear stability analysis of the STF allows us to derive a power spectrum for the surface fluctuations, which is quantitatively validated against the spectrum observed in MD. Thermal fluctuations are shown to be critical to the dynamics of nanoscale films. Compared to the classical instability mechanism, which is driven by disjoining pressure, fluctuations (a) can massively amplify the instability, (b) cause the fluctuation wavelength that is dominant to evolve in time (a single fastest-growing mode does not exist), and (c) decrease the critical wavelength so that classically stable films can be ruptured.
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Affiliation(s)
- Yixin Zhang
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - James E Sprittles
- Mathematics Institute, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Duncan A Lockerby
- School of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
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Surface, Interface, and Temperature Effects on the Phase Separation and Nanoparticle Self Assembly of Bi-Metallic Ni0.5Ag0.5: A Molecular Dynamics Study. NANOMATERIALS 2019; 9:nano9071040. [PMID: 31330888 PMCID: PMC6669487 DOI: 10.3390/nano9071040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/10/2019] [Accepted: 07/19/2019] [Indexed: 11/16/2022]
Abstract
Classical molecular dynamics (MD) simulations were used to investigate how free surfaces, as well as supporting substrates, affect phase separation in a NiAg alloy. Bulk samples, droplets, and droplets deposited on a graphene substrate were investigated at temperatures that spanned regions of interest in the bulk NiAg phase diagram, i.e., miscible and immiscible liquid, liquid-crystal, and crystal-crystal regions. Using MD simulations to cool down a bulk sample from 3000 K to 800 K, it was found that phase separation below 2400 K takes place in agreement with the phase diagram. When free surface effects were introduced, phase separation was accompanied by a core-shell transformation: spherical droplets created from the bulk samples became core-shell nanoparticles with a shell made mostly of Ag atoms and a core made of Ni atoms. When such droplets were deposited on a graphene substrate, the phase separation was accompanied by Ni layering at the graphene interface and Ag at the vacuum interface. Thus, it should be possible to create NiAg core-shell and layer-like nanostructures by quenching liquid NiAg samples on tailored substrates. Furthermore, interesting bimetallic nanoparticle morphologies might be tuned via control of the surface and interface energies and chemical instabilities of the system.
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Oh H, Lee J, Seo M, Baek IU, Byun JY, Lee M. Laser-Induced Dewetting of Metal Thin Films for Template-Free Plasmonic Color Printing. ACS APPLIED MATERIALS & INTERFACES 2018; 10:38368-38375. [PMID: 30360063 DOI: 10.1021/acsami.8b13675] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Plasmonic color laser printing has several advantages over pigment-based technology, including the absence of ink and toner and the production of nonfading colors. However, the current printing method requires a template that should be prepared via nanofabrication processes, making it impractical for large-area color images. In this study, we show that laser-induced dewetting of metal thin films by a nanosecond pulsed laser can be effectively utilized for plasmonic color printing. Ag, Au, and their complex films deposited on a glass substrate were dewetted into different surface structures such as droplets, rods, and ripples, depending on the incident laser energy. The resulting morphological evolutions could be explained by Rayleigh and capillary instabilities. For a bimetallic film comprising Ag nanowires coated on a Au layer, a few different plasmonic colors were generated from a single sample simply by changing the laser fluence. This provides a possible method for implementing plasmonic color laser printing without using a prepatterned template.
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Affiliation(s)
- Harim Oh
- Department of Materials Science and Engineering , Yonsei University , Seoul 120-749 , Korea
| | - Jeeyoung Lee
- Department of Materials Science and Engineering , Yonsei University , Seoul 120-749 , Korea
| | - Minseok Seo
- Department of Materials Science and Engineering , Yonsei University , Seoul 120-749 , Korea
| | - In Uk Baek
- Materials Architecture Research Center , Korea Institute of Science and Technology , Seoul 02792 , Korea
| | - Ji Young Byun
- Materials Architecture Research Center , Korea Institute of Science and Technology , Seoul 02792 , Korea
| | - Myeongkyu Lee
- Department of Materials Science and Engineering , Yonsei University , Seoul 120-749 , Korea
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Experimental Analysis on the Molten-Phase Dewetting Characteristics of AuPd Alloy Films on Topographically-Structured Substrates. METALS 2017. [DOI: 10.3390/met7090327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Maekawa Y, Shibuta Y. Dewetting dynamics of nickel thin film on alpha-quartz substrate: A molecular dynamics study. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Yadavali S, Sandireddy VP, Kalyanaraman R. Transformation of irregular shaped silver nanostructures into nanoparticles by under water pulsed laser melting. NANOTECHNOLOGY 2016; 27:195602. [PMID: 27041091 DOI: 10.1088/0957-4484/27/19/195602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The ability to easily manufacture nanostructures with a desirable attribute, such as well-defined size and shape, especially from any given initial shapes or sizes of the material, will be helpful towards accelerating the use of nanomaterials in various applications. In this work we report the transformation of discontinuous irregular nanostructures (DIN) of silver metal by rapid heating under a bulk fluid layer. Ag films were changed into DIN by dewetting in air and subsequently heated by nanosecond laser pulses under water. Our findings show that the DIN first ripens into elongated structures and then breaks up into nanoparticles. From the dependence of this behavior on laser fluence we found that under water irradiation reduced the rate of ripening and also decreased the characteristic break-up length scale of the elongated structures. This latter result was qualitatively interpreted as arising from a Rayleigh-Plateau instability modified to yield significantly smaller length scales than the classical process due to pressure gradients arising from the rapid evaporation of water during laser melting. These results demonstrate that it is possible to fabricate a dense collection of monomodally sized Ag nanoparticles with significantly enhanced plasmonic quality starting from the irregular shaped materials. This can be beneficial towards transforming discontinuous Ag films into nanostructures with useful plasmonic properties, that are relevant for biosensing applications.
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Affiliation(s)
- S Yadavali
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996, USA
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Diez JA, González AG, Fernández R. Metallic-thin-film instability with spatially correlated thermal noise. Phys Rev E 2016; 93:013120. [PMID: 26871167 DOI: 10.1103/physreve.93.013120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/07/2022]
Abstract
We study the effects of stochastic thermal fluctuations on the instability of the free surface of a flat liquid metallic film on a solid substrate. These fluctuations are represented by a stochastic noise term added to the deterministic equation for the film thickness within the long-wave approximation. Unlike the case of polymeric films, we find that this noise, while remaining white in time, must be colored in space, at least in some regimes. The corresponding noise term is characterized by a nonzero correlation length, ℓ_{c}, which, combined with the size of the system, leads to a dimensionless parameter β that accounts for the relative importance of the spatial correlation (β∼ℓ_{c}^{-1}). We perform the linear stability analysis (LSA) of the film both with and without the noise term and find that for ℓ_{c} larger than some critical value (depending on the system size), the wavelength of the peak of the spectrum is larger than that corresponding to the deterministic case, while for smaller ℓ_{c} this peak corresponds to smaller wavelength than the latter. Interestingly, whatever the value of ℓ_{c}, the peak always approaches the deterministic one for larger times. We compare LSA results with the numerical simulations of the complete nonlinear problem and find a good agreement in the power spectra for early times at different values of β. For late times, we find that the stochastic LSA predicts well the position of the dominant wavelength, showing that nonlinear interactions do not modify the trends of the early linear stages. Finally, we fit the theoretical spectra to experimental data from a nanometric laser-melted copper film and find that at later times, the adjustment requires smaller values of β (larger space correlations).
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Affiliation(s)
- Javier A Diez
- Instituto de Física Arroyo Seco (CIFICEN-CONICET), Universidad Nacional del Centro de la Provicia de Buenos Aires, Pinto 399, 7000, Tandil, Argentina
| | - Alejandro G González
- Instituto de Física Arroyo Seco (CIFICEN-CONICET), Universidad Nacional del Centro de la Provicia de Buenos Aires, Pinto 399, 7000, Tandil, Argentina
| | - Roberto Fernández
- Department of Mathematics, Utrecht University, P. O. Box 80010 3508 TA Utrecht
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Nesic S, Cuerno R, Moro E, Kondic L. Fully nonlinear dynamics of stochastic thin-film dewetting. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:061002. [PMID: 26764623 DOI: 10.1103/physreve.92.061002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Indexed: 06/05/2023]
Abstract
The spontaneous formation of droplets via dewetting of a thin fluid film from a solid substrate allows materials nanostructuring. Often, it is crucial to be able to control the evolution, and to produce patterns characterized by regularly spaced droplets. While thermal fluctuations are expected to play a role in the dewetting process, their relevance has remained poorly understood, particularly during the nonlinear stages of evolution that involve droplet formation. Within a stochastic lubrication framework, we show that thermal noise substantially influences the process of droplets formation. Stochastic systems feature a smaller number of droplets with a larger variability in size and space distribution, when compared to their deterministic counterparts. Finally, we discuss the influence of stochasticity on droplet coarsening for asymptotically long times.
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Affiliation(s)
- S Nesic
- Departamento de Matemáticas & Grupo Interdisciplinar de Sistemas Complejos (GISC), Universidad Carlos III de Madrid, 28911 Leganés, Spain
| | - R Cuerno
- Departamento de Matemáticas & Grupo Interdisciplinar de Sistemas Complejos (GISC), Universidad Carlos III de Madrid, 28911 Leganés, Spain
| | - E Moro
- Departamento de Matemáticas & Grupo Interdisciplinar de Sistemas Complejos (GISC), Universidad Carlos III de Madrid, 28911 Leganés, Spain
| | - L Kondic
- Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey, USA
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Wu Y, Dong N, Fu S, Fowlkes JD, Kondic L, Vincenti MA, de Ceglia D, Rack PD. Directed liquid phase assembly of highly ordered metallic nanoparticle arrays. ACS APPLIED MATERIALS & INTERFACES 2014; 6:5835-5843. [PMID: 24689648 DOI: 10.1021/am500695h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Directed assembly of nanomaterials is a promising route for the synthesis of nanoscale materials. In this paper, we demonstrate the directed-assembly of highly ordered two-dimensional arrays of hierarchical nanostructures with tunable size, spacing and composition. The directed assembly is achieved on lithographically patterned metal films that are subsequently pulse-laser melted; during the brief liquid lifetime, the pattened nanostructures assemble into highly ordered primary and secondary nanoparticles, with sizes below that which was originally patterned. Complementary fluid-dynamics simulations emulate the resultant patterns and show how the competition of capillary forces and liquid metal-solid substrate interaction potential drives the directed assembly. As an example of the enhanced functionality, a full-wave electromagnetic analysis has been performed to identify the nature of the supported plasmonic resonances.
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Affiliation(s)
- Yueying Wu
- Department of Materials Science and Engineering, The University of Tennessee , Knoxville, Tennessee 37996, United States
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