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Peschka D, Haefner S, Marquant L, Jacobs K, Münch A, Wagner B. Signatures of slip in dewetting polymer films. Proc Natl Acad Sci U S A 2019; 116:9275-9284. [PMID: 31004049 PMCID: PMC6510987 DOI: 10.1073/pnas.1820487116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Thin polymer films on hydrophobic substrates are susceptible to rupture and hole formation. This, in turn, initiates a complex dewetting process, which ultimately leads to characteristic droplet patterns. Experimental and theoretical studies suggest that the type of droplet pattern depends on the specific interfacial condition between the polymer and the substrate. Predicting the morphological evolution over long timescales and on the different length scales involved is a major computational challenge. In this study, a highly adaptive numerical scheme is presented, which allows for following the dewetting process deep into the nonlinear regime of the model equations and captures the complex dynamics, including the shedding of droplets. In addition, our numerical results predict the previously unknown shedding of satellite droplets during the destabilization of liquid ridges that form during the late stages of the dewetting process. While the formation of satellite droplets is well known in the context of elongating fluid filaments and jets, we show here that, for dewetting liquid ridges, this property can be dramatically altered by the interfacial condition between polymer and substrate, namely slip. This work shows how dissipative processes can be used to systematically tune the formation of patterns.
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Affiliation(s)
- Dirk Peschka
- Weierstrass Institute for Applied Analysis and Stochastics, 10117 Berlin, Germany;
| | - Sabrina Haefner
- Experimental Physics and Center for Biophysics, Saarland University, 66041 Saarbrücken, Germany
| | - Ludovic Marquant
- Experimental Physics and Center for Biophysics, Saarland University, 66041 Saarbrücken, Germany
| | - Karin Jacobs
- Experimental Physics and Center for Biophysics, Saarland University, 66041 Saarbrücken, Germany
| | - Andreas Münch
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Barbara Wagner
- Weierstrass Institute for Applied Analysis and Stochastics, 10117 Berlin, Germany
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2
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McClements J, Buffone C, Shaver MP, Sefiane K, Koutsos V. Poly(styrene-co-butadiene) random copolymer thin films and nanostructures on a mica surface: morphology and contact angles of nanodroplets. SOFT MATTER 2017; 13:6152-6166. [PMID: 28795749 DOI: 10.1039/c7sm00994a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The self-assembly of poly(styrene-co-butadiene) random copolymers on mica surfaces was studied by varying solution concentrations and polymer molecular weights. Toluene solutions of the poly(styrene-co-butadiene) samples were spin coated onto a mica surface and the resulting polymer morphology was investigated by atomic force microscopy. At higher concentrations, thin films formed with varying thicknesses; some dewetting was observed which depended on the molecular weight. Total dewetting did not occur despite the polymer's low glass transition temperature. Instead, partial dewetting was observed suggesting that the polymer was in a metastable equilibrium state. At lower concentrations, spherical cap shaped nanodroplets formed with varying sizes from single polymer chains to aggregates containing millions of chains. As the molecular weight was increased, fewer aggregates were observed on the surface, albeit with larger sizes resulting from increased solution viscosities and more chain entanglements at higher molecular weights. The contact angles of the nanodroplets were shown to be size dependent. A minimum contact angle occurs for droplets with radii of 100-250 nm at each molecular weight. Droplets smaller than 100 nm showed a sharp increase in contact angle; attributed to an increase in the elastic modulus of the droplets, in addition, to a positive line tension value. Droplets larger than 250 nm also showed an increased contact angle due to surface heterogeneities which cannot be avoided for larger droplets. This increase in contact angle plateaus as the droplet size reaches the macroscopic scale.
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Affiliation(s)
- Jake McClements
- Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Sanderson Building, King's Buildings, Edinburgh EH9 3FB, UK.
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3
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Ohk CW, Koo M, Lee BJ, Lee SE, Jang HS, Park YC. Slip behavior in polymethylmethacrylate films in dependence of self-assembled monolayer wettability. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.10.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Bäumchen O, Marquant L, Blossey R, Münch A, Wagner B, Jacobs K. Influence of slip on the Rayleigh-Plateau rim instability in dewetting viscous films. PHYSICAL REVIEW LETTERS 2014; 113:014501. [PMID: 25032928 DOI: 10.1103/physrevlett.113.014501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Indexed: 06/03/2023]
Abstract
A dewetting viscous film develops a characteristic fluid rim at its receding edge due to mass conservation. In the course of the dewetting process, the rim becomes unstable via an instability of Rayleigh-Plateau type. An important difference exists between this classic instability of a liquid column and the rim instability in a thin film as the growth of the rim is continuously fueled by the receding film. We explain how the development and macroscopic morphology of the rim instability are controlled by the slip of the film on the substrate. A single thin-film model captures quantitatively the characteristics of the complete evolution of the rim observed in the experiments.
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Affiliation(s)
- Oliver Bäumchen
- Saarland University, Department of Experimental Physics, Campus, D-66123 Saarbrücken, Germany
| | - Ludovic Marquant
- Saarland University, Department of Experimental Physics, Campus, D-66123 Saarbrücken, Germany
| | - Ralf Blossey
- Interdisciplinary Research Institute (IRI), CNRS USR 3078, 59658 Villeneuve d'Ascq, France
| | - Andreas Münch
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Barbara Wagner
- Technical University of Berlin, Institute for Mathematics, D-10623 Berlin, Germany
| | - Karin Jacobs
- Saarland University, Department of Experimental Physics, Campus, D-66123 Saarbrücken, Germany
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5
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Ma M, Chen F, Wang K, Zhang Q, Deng H, Li Z, Fu Q. Anisotropic Dewetting Holes with Instability Fronts in Ultrathin Films of Polystyrene/Poly(ε-caprolactone) Blend. Macromolecules 2012. [DOI: 10.1021/ma3000779] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Meng Ma
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Feng Chen
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Ke Wang
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Qin Zhang
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Hua Deng
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Zhongming Li
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Qiang Fu
- College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
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Münch A, Wagner B. Impact of slippage on the morphology and stability of a dewetting rim. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:184101. [PMID: 21508486 DOI: 10.1088/0953-8984/23/18/184101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this study lubrication theory is used to describe the stability and morphology of the rim that forms as a thin polymer film dewets from a hydrophobized silicon wafer. Thin film equations are derived from the governing hydrodynamic equations for the polymer to enable the systematic mathematical and numerical analysis of the properties of the solutions for different regimes of slippage and for a range of timescales. Dewetting rates and the cross sectional profiles of the evolving rims are derived for these models and compared to experimental results. Experiments also show that the rim is typically unstable in the spanwise direction and develops thicker and thinner parts that may grow into 'fingers'. Linear stability analysis as well as nonlinear numerical solutions are presented to investigate shape and growth rate of the rim instability. It is demonstrated that the difference in morphology and the rate at which the instability develops can be directly attributed to the magnitude of slippage. Finally, a derivation is given for the dominant wavelength of the bulges along the unstable rim.
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Affiliation(s)
- Andreas Münch
- Mathematical Institute, University of Oxford, Oxford, UK
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Zhu D, Li X, Zhang G, Zhang X, Zhang X, Wang T, Yang B. Mimicking the rice leaf--from ordered binary structures to anisotropic wettability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14276-14283. [PMID: 20677764 DOI: 10.1021/la102243c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this paper, we report a method to fabricate a series of surfaces with large-area ordered binary arrays by controllable dewetting. The binary structure arrays consist of an ordered-stripe array and droplet-row array. In order to expand the system, polystyrene (PS) and poly(methyl methacrylate) (PMMA) are introduced in this experiment for investigation in detail. Through adjustment of the polymer solution concentration and the modified underlying pattern on substrate, the surface topographies can be controlled simply. Accordingly, three types of topographies with ordered binary arrays have been obtained by thermal annealing. These unique surfaces mimic the natural rice leaf structurally, which also displays anisotropic wettability for water droplet as natural surfaces. This method points out a new way for the manufacture of functional surfaces.
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Affiliation(s)
- Difu Zhu
- State Key Laboratory for Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, PR China
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9
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Park DK, Kim HI, Kim JP, Park JS, Lee SY, Yang SM, Lee J, Chung CH, Sim SJ, Yoo PJ. Rigiflex lithography-based nanodot arrays for localized surface plasmon resonance biosensors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:6119-6126. [PMID: 20369840 DOI: 10.1021/la100598v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We present a facile and robust means of fabricating metallic nanodot arrays for localized surface plasmon resonance (LSPR) biosensors through the strategic coupling of a polymeric template prepared with rigiflex lithography and a subsequent metallization via electrodeposition. Rigiflex lithography provides the capability to realize large-scale nanosized features as well as process flexibility during contact molding. In addition, the electrodeposition process enables wet-based nanoscale metallization with high pattern fidelity and geometric controllability. Generated metallic nanodot arrays can be used as a general platform for LSPR biosensors via the sequential binding of chemicals and biomolecules. Extinction spectra of the corresponding LSPR signal are measured with UV-vis-NIR spectroscopy, from which the pattern size and shape dependence of LSPR are readily confirmed. The feasibility of a very sensitive biosensor is demonstrated by the targeted binding of human immunoglobulin G, yielding subnanomolar detection capability with high selectivity.
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Affiliation(s)
- Dong Kyu Park
- School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea
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10
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You J, Hu S, Liao Y, Song K, Men Y, Shi T, An L. Composition effect on dewetting of ultrathin films of miscible polymer blend. POLYMER 2009. [DOI: 10.1016/j.polymer.2009.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Xue L, Han Y. Autophobic dewetting of a poly(methyl methacrylate) thin film on a silicon wafer treated in good solvent vapor. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:5135-5140. [PMID: 19278204 DOI: 10.1021/la8041814] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The wettability of thin poly(methyl methacrylate) (PMMA) films on a silicon wafer with a native oxide layer exposed to solvent vapors is dependent on the solvent properties. In the nonsolvent vapor, the film spread on the substrate with some protrusions generated on the film surface. In the good solvent vapor, dewetting happened. A new interface formed between the anchored PMMA chains and the swollen upper part of the film. Entropy effects caused the upper movable chains to dewet on the anchored chains. The rim instability depended on the surface tension of solvent (i.e., the finger was generated in acetone vapor (gamma(acetone) = 24 mN/m), not in dioxane vapor (gamma(dioxane) = 33 mN/m)). The spacing (lambda) that grew as an exponential function of film thickness h scaled as approximately h(1.31), whereas the mean size (D) of the resulting droplets grew linearly with h.
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Affiliation(s)
- Longjian Xue
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, PR China
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12
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Xu L, Shi T, Dutta PK, An L. Rim instability by solvent-induced dewetting. J Chem Phys 2007; 127:144704. [DOI: 10.1063/1.2770734] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yang MH, Hou SY, Chang YL, Yang ACM. Molecular recoiling in polymer thin film dewetting. PHYSICAL REVIEW LETTERS 2006; 96:066105. [PMID: 16606016 DOI: 10.1103/physrevlett.96.066105] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2005] [Indexed: 05/08/2023]
Abstract
The molecular recoiling force stemming from nonequilibrium chain conformation was found to play a very important role in the dewetting stability of polymer thin films. Correct measurements and inclusion of this molecular force into thermodynamic consideration are crucial for analyzing dewetting phenomena and nanoscale polymer chain physics. This force was measured using a simple method based on contour relaxation at the incipient dewetting holes. The recoiling stress was found to increase dramatically with molecular weight and decreasing film thickness. The corresponding forces were calculated to be in the range from 9.0 to 28.2 mN/m, too large to be neglected when compared to the dispersive forces (approximately 10 mN/m) commonly operative in thin polymer films.
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Affiliation(s)
- M H Yang
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
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14
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Choi SH, Newby BMZ. Dynamic contact angle in rim instability of dewetting holes. J Chem Phys 2006; 124:054702. [PMID: 16468896 DOI: 10.1063/1.2162534] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effects of dynamic contact angle (thetad), between a substrate and the melt of a dewetting polymer thin film, on the evolution of rim instabilities of dewetting holes were reported. Various thetad's were achieved by covering SiOx surfaces with different coverage of octadecyltrichlorosilane. On each surface, the morphology of the dewetting holes was examined in detail as the hole grew to a certain size. Rim instabilities, in terms of undulations in both r and z directions, became more pronounced as thetad increased, under which condition, narrower and higher rims were also observed. Experimentally, atomic force microscopic scans of the rim were used to obtain the rim profile, which was predicted using thetad. The predicted rim profile was used, in combination with the analysis of Rayleigh instability of a cylindrical fluid, to interpret the rim instability. The model captures the basic trend of the rim instability dependency on thetad. The study demonstrates the importance of the substrate properties on the rim instability and the destabilization of polymer thin films during hole growth.
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Affiliation(s)
- Sung-Hwan Choi
- Department of Chemical Engineering, The University of Akron, Akron, Ohio 44325-3906, USA
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15
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Karapanagiotis I, Gerberich WW. Particle nucleation for dewetting initiation of thin polymer films. J Appl Polym Sci 2005. [DOI: 10.1002/app.22028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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16
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Besancon BM, Green PF. Polystyrene-Based Single-Walled Carbon Nanotube Nanocomposite Thin Films: Dynamics of Structural Instabilities. Macromolecules 2005. [DOI: 10.1021/ma049008+] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Besancon BM, Green PF. Moving fronts in entangled polymeric films. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 70:051808. [PMID: 15600647 DOI: 10.1103/physreve.70.051808] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Revised: 08/02/2004] [Indexed: 05/24/2023]
Abstract
Thin liquid films can become structurally unstable and dewet, forming holes which subsequently grow on the substrate. Considerable research has been conducted on the structural evolution and growth of holes, which invariably are shown to be circular. We show that morphologies characterized by circular holes comprise one of three possible morphological regimes. In polystyrene films, supported by silicon oxide substrates, two other regimes are observed with decreasing film thickness. In the second regime, the moving boundary of the growing hole may become unstable and form fingers. The spacing between the fingers is characterized by a well-defined wavelength lambda proportional to h(7/6) M(-1/2) , where h is the film thickness and M is the molecular weight. A dense branchlike morphology characterizes the peripheral regions of the holes in the third regime and is found only in the thinnest films.
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Affiliation(s)
- Brian M Besancon
- Department of Chemical Engineering and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA
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Hagedorn JG, Martys NS, Douglas JF. Breakup of a fluid thread in a confined geometry: droplet-plug transition, perturbation sensitivity, and kinetic stabilization with confinement. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:056312. [PMID: 15244937 DOI: 10.1103/physreve.69.056312] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2003] [Indexed: 05/24/2023]
Abstract
We investigate the influence of geometrical confinement on the breakup of long fluid threads in the absence of imposed flow using a lattice Boltzmann model. Our simulations primarily focus on the case of threads centered coaxially in a tube filled with another Newtonian fluid and subjected to both impulsive and random perturbations. We observe a significant slowing down of the rate of thread breakup ("kinetic stabilization") over a wide range of the confinement, Lambda= R(tube)/R(thread) < or =10 and find that the relative surface energies of the liquid components influence this effect. For Lambda<2.3, there is a transition in the late-stage morphology between spherical droplets and tube "plugs." Unstable distorted droplets ("capsules") form as transient structures for intermediate confinement (Lambda approximately equal 2.1-2.5). Surprisingly, the thread breakup process for more confined threads (Lambda< or =1.9 ) is found to be sensitive to the nature of the initial thread perturbation. Localized impulsive perturbations ("taps") cause a "bulging" of the fluid at the wall, followed by thread breakup through the propagation of a wave-like disturbance ("end-pinch instability") initiating from the thread rupture point. Random impulses along the thread, modeling thermal fluctuations, lead to a complex breakup process involving a competition between the Raleigh and end-pinch instabilities. We also briefly compare our tube simulations to threads confined between parallel plates and to multiple interacting threads under confinement.
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Affiliation(s)
- John G Hagedorn
- Mathematical and Computational Sciences Division, Nantional Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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Meli L, Pham JQ, Johnston KP, Green PF. Polystyrene thin films in CO(2). PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:051601. [PMID: 15244823 DOI: 10.1103/physreve.69.051601] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Revised: 01/28/2004] [Indexed: 05/24/2023]
Abstract
In air, or vacuum environments, liquid polystyrene (PS) thin films (thickness, h<100 nm ) supported by SiOx /Si substrates are structurally metastable or unstable, depending on film thickness. They rupture and eventually form droplets on the SiOx /Si substrates (dewet) due to the influence of destabilizing long-ranged van der Waals dispersion forces. We used scanning force microscopy to examine the structural stability of liquid PS films in the thickness range 5 nm<h<100 nm in liquid and in supercritical carbon dioxide ( CO2 ) environments. All films in this thickness range were metastable; holes developed throughout the films and over time these holes grew, impinged, and eventually formed droplets. The rate of destabilization is controlled by three factors: film thickness, temperature, and CO2 pressure (which dictates CO2 volume fraction in the films). Calculations of the effective interface potentials suggest that the energy barrier for nucleation and growth of holes in CO2 is larger than that in air, and in the limit of vanishingly low PS volume fraction the films should be stable.
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Affiliation(s)
- Luciana Meli
- Department of Chemical Engineering and Texas Material Institute, The University of Texas at Austin, Austin, Texas 78712, USA
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Gu X, Raghavan D, Douglas JF, Karim A. Hole-growth instability in the dewetting of evaporating polymer solution films. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/polb.10347] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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