1
|
Milchev A, Binder K. Surface enrichment and interdiffusion in blends of semiflexible polymers of different stiffness. SOFT MATTER 2022; 18:3781-3792. [PMID: 35514321 DOI: 10.1039/d2sm00036a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A model for a mixture of two kinds of semiflexible polymers (A and B) with the same chain length (NA = NB = 32), but different persistence lengths, confined between parallel planar repulsive walls in a common good solvent is studied by molecular dynamics simulations. In the isotropic phase at low polymer concentrations, both polymers are repelled by the walls, and the system is anisotropic near the walls over a range controlled by the polymer linear dimensions. Close to the concentrations where in the bulk nematic order sets in, precursors of thick nematic layers at the walls are observed, strongly enriched by a stiffer component, which hence is depleted in the center of the slit pore. At larger concentrations, where in the bulk a uniformly mixed nematic phase occurs, the enrichment of B-chains at the walls is rather minor, extending over the scale of the transverse correlation length of concentration fluctuations, which is of the order of a few monomeric diameters only for the present model. In this ordered phase, both self-diffusion and interdiffusion of chains (in the direction perpendicular to the director) are found to be significantly slowed down in comparison to dilute solutions. Since equilibration times scale with the square of the slit thickness, incomplete equilibration is predicted when polymeric coatings on substrate containing polymers differing in stiffness are produced.
Collapse
Affiliation(s)
- Andrey Milchev
- Institute for Physical Chemistry, Bulgarian Academia of Sciences, 1113, Sofia, Bulgaria.
| | - Kurt Binder
- Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
| |
Collapse
|
2
|
Maguire SM, Boyle MJ, Bilchak CR, Demaree JD, Keller AW, Krook NM, Ohno K, Kagan CR, Murray CB, Rannou P, Composto RJ. Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films. ACS APPLIED MATERIALS & INTERFACES 2021; 13:37628-37637. [PMID: 34324291 DOI: 10.1021/acsami.1c09233] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Wetting of polymer-grafted nanoparticles (NPs) in a polymer nanocomposite (PNC) film is driven by a difference in surface energy between components as well as bulk thermodynamics, namely, the value of the interaction parameter, χ. The interplay between these contributions is investigated in a PNC containing 25 wt % polymethyl methacrylate (PMMA)-grafted silica NPs (PMMA-NPs) in poly(styrene-ran-acrylonitrile) (SAN) upon annealing above the lower critical solution temperature (LCST, 160 °C). Atomic force microscopy (AFM) studies show that the areal density of particles increases rapidly and then approaches 80% of that expected for random close-packed hard spheres. A slightly greater areal density is observed at 190 °C compared to 170 °C. The PMMA-NPs are also shown to prevent dewetting of PNC films under conditions where the analogous polymer blend is unstable. Transmission electron microscopy (TEM) imaging shows that PMMA-NPs symmetrically wet both interfaces and form columns that span the free surface and substrate interface. Using grazing-incidence Rutherford backscattering spectrometry (GI-RBS), the PMMA-NP surface excess (Z*) initially increases rapidly with time and then approaches a constant value at longer times. Consistent with the areal density, Z* is slightly greater at deeper quench depths, which is attributed to the more unfavorable interactions between the PMMA brush and SAN segments. The Z* values at early times are used to determine the PMMA-NP diffusion coefficients, which are significantly larger than theoretical predictions. These studies provide insights into the interplay between wetting and phase separation in PNCs and can be utilized in nanotechnology applications where surface-dependent properties, such as wettability, durability, and friction, are important.
Collapse
Affiliation(s)
- Shawn M Maguire
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael J Boyle
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Connor R Bilchak
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - John Derek Demaree
- US Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, United States
| | - Austin W Keller
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Nadia M Krook
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kohji Ohno
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Cherie R Kagan
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christopher B Murray
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrice Rannou
- Univ. Grenoble Alpes, CNRS, CEA, IRIG-SyMMES, 38000 Grenoble, France
| | - Russell J Composto
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
3
|
Li F, Zhang Y, Zhao X, Chen Q, Li Y, You J. Graft ratio: Quantitative measurement and direct evidence for its blending sequence dependence during reactive compatibilization in PVDF/PLLA. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.121970] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
4
|
Erukhimovich I, Kriksin Y, ten Brinke G. Ordering Lamellar-Forming Copolymer Thin Films in 3D Bicontinuous Morphologies via Lamellar Patterned Substrate. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02692] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- I. Erukhimovich
- Nesmeyanov
Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow 119991, Russia
| | - Y. Kriksin
- Keldysh
Institute of Applied Mathematics, Russian Academy of Sciences, Moscow 125047, Russia
| | - G. ten Brinke
- Department
of Polymer Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| |
Collapse
|
5
|
Erukhimovich I, Kriksin Y, ten Brinke G. Diamond-Forming Block Copolymers and Diamond-like Morphologies: A New Route toward Efficient Block Copolymer Membranes. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b01513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- I. Erukhimovich
- Nesmeyanov
Institute of Organoelement Compounds, RAS, Moscow 119991, Russia
| | - Y. Kriksin
- Keldysh
Institute of Applied Mathematics, RAS, Moscow 125047, Russia
| | - G. ten Brinke
- Department
of Polymer Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| |
Collapse
|
6
|
Rodríguez-Hernández J. Wrinkled interfaces: Taking advantage of surface instabilities to pattern polymer surfaces. Prog Polym Sci 2015. [DOI: 10.1016/j.progpolymsci.2014.07.008] [Citation(s) in RCA: 218] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
7
|
Dissipative Particle Dynamics: A Method to Simulate Soft Matter Systems in Equilibrium and Under Flow. SELECTED TOPICS OF COMPUTATIONAL AND EXPERIMENTAL FLUID MECHANICS 2015. [DOI: 10.1007/978-3-319-11487-3_3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
8
|
Zhang S, Zhu Y, Shi T, Zhao H, You J, Li Y. Selective solvent annealing induced phase separation and dewetting in PMMA/SAN blend ultrathin films. ACTA ACUST UNITED AC 2014. [DOI: 10.1002/polb.23541] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Shuangshuang Zhang
- College of Material; Chemistry and Chemical Engineering, Hangzhou Normal University; No. 16, Xuelin Road Xiasha High-tech Zone Hangzhou 310036 People's Republic of China
| | - Yu Zhu
- College of Material; Chemistry and Chemical Engineering, Hangzhou Normal University; No. 16, Xuelin Road Xiasha High-tech Zone Hangzhou 310036 People's Republic of China
| | - Tongfei Shi
- State Key Laboratory of Polymer Physics and Chemistry; Changchun Institute of Applied Chemistry, Chinese Academy of Sciences; Changchun 130022 People's Republic of China
| | - Hui Zhao
- Department of Polymer Science and Engineering; Zhejiang University; Hangzhou 310027 People's Republic of China
| | - Jichun You
- College of Material; Chemistry and Chemical Engineering, Hangzhou Normal University; No. 16, Xuelin Road Xiasha High-tech Zone Hangzhou 310036 People's Republic of China
| | - Yongjin Li
- College of Material; Chemistry and Chemical Engineering, Hangzhou Normal University; No. 16, Xuelin Road Xiasha High-tech Zone Hangzhou 310036 People's Republic of China
| |
Collapse
|
9
|
Maniadis P, Tsimpanogiannis I, Kober E, Lookman T. Morphology of diblock copolymers in porous media. Mol Phys 2014. [DOI: 10.1080/00268976.2014.886736] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
10
|
You J, Zhang S, Huang G, Shi T, Li Y. Solvent annealing induced phase separation and dewetting in PMMA/SAN blend film: Film thickness and solvent dependence. J Chem Phys 2013; 138:244907. [DOI: 10.1063/1.4811471] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
11
|
Binder K, Milchev A. Polymer brushes on flat and curved surfaces: How computer simulations can help to test theories and to interpret experiments. ACTA ACUST UNITED AC 2012. [DOI: 10.1002/polb.23168] [Citation(s) in RCA: 166] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
12
|
Wilms D, Wilding NB, Binder K. Transitions between imperfectly ordered crystalline structures: a phase switch Monte Carlo study. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:056703. [PMID: 23004899 DOI: 10.1103/physreve.85.056703] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Indexed: 06/01/2023]
Abstract
A model for two-dimensional colloids confined laterally by "structured boundaries" (i.e., ones that impose a periodicity along the slit) is studied by Monte Carlo simulations. When the distance D between the confining walls is reduced at constant particle number from an initial value D(0), for which a crystalline structure commensurate with the imposed periodicity fits, to smaller values, a succession of phase transitions to imperfectly ordered structures occur. These structures have a reduced number of rows parallel to the boundaries (from n to n-1 to n-2, etc.) and are accompanied by an almost periodic strain pattern, due to "soliton staircases" along the boundaries. Since standard simulation studies of such transitions are hampered by huge hysteresis effects, we apply the phase switch Monte Carlo method to estimate the free energy difference between the structures as a function of the misfit between D and D(0), thereby locating where the transitions occur in equilibrium. For comparison, we also obtain this free energy difference from a thermodynamic integration method: The results agree, but the effort required to obtain the same accuracy as provided by phase switch Monte Carlo would be at least three orders of magnitude larger. We also show for a situation where several "candidate structures" exist for a phase, that phase switch Monte Carlo can clearly distinguish the metastable structures from the stable one. Finally, applying the method in the conjugate statistical ensemble (where the normal pressure conjugate to D is taken as an independent control variable), we show that the standard equivalence between the conjugate ensembles of statistical mechanics is violated.
Collapse
Affiliation(s)
- Dorothea Wilms
- Institut für Physik, Johannes Gutenberg Universität Mainz, Germany
| | | | | |
Collapse
|
13
|
|
14
|
Budkowski A, Zemła J, Moons E, Awsiuk K, Rysz J, Bernasik A, Björström-Svanström CM, Lekka M, Jaczewska J. Polymer blends spin-cast into films with complementary elements for electronics and biotechnology. J Appl Polym Sci 2012. [DOI: 10.1002/app.36574] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
15
|
Adhikari NP, Straube E. Phase separation in mixtures of flexible and semiflexible polymers. Polym J 2011. [DOI: 10.1038/pj.2011.29] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
16
|
Vink RLC, Neuhaus T, Löwen H. Fluid phase separation inside a static periodic field: An effectively two-dimensional critical phenomenon. J Chem Phys 2011; 134:204907. [DOI: 10.1063/1.3582903] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
You J, Liao Y, Men Y, Shi T, An L. Film thickness dependence of phase separation and dewetting behaviors in PMMA/SAN blend films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14530-14534. [PMID: 20722461 DOI: 10.1021/la102680b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Film thickness dependence of complex behaviors coupled by phase separation and dewetting in blend [poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN)] films on silicon oxide substrate at 175 °C was investigated by grazing incidence ultrasmall-angle X-ray scattering (GIUSAX) and in situ atomic force microscopy (AFM). It was found that the dewetting pathway was under the control of the parameter U(q0)/E, which described the initial amplitude of the surface undulation and original thickness of film, respectively. Furthermore, our results showed that interplay between phase separation and dewetting depended crucially on film thickness. Three mechanisms including dewetting-phase separation/wetting, dewetting/wetting-phase separation, and phase separation/wetting-pseudodewetting were discussed in detail. In conclusion, it is relative rates of phase separation and dewetting that dominate the interplay between them.
Collapse
Affiliation(s)
- Jichun You
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | | | | | | | | |
Collapse
|
18
|
Petrus P, Lísal M, Brennan JK. Self-assembly of lamellar- and cylinder-forming diblock copolymers in planar slits: insight from dissipative particle dynamics simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14680-14693. [PMID: 20795714 DOI: 10.1021/la102666g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We present a dissipative particle dynamics simulation study on nanostructure formation of symmetric and asymmetric diblock copolymers confined between planar surfaces. We consider symmetric and slightly asymmetric diblock copolymers that form lamellar nanostructures in the bulk, and highly asymmetric diblock copolymers that form cylindrical nanostructures in the bulk. The formation of the diblock copolymer nanostructures confined between the planar surfaces is investigated and characterized by varying the separation width and the strength of the interaction between the surfaces and the diblock copolymers. Both the slit width and the surface interaction strongly influence the phase diagram, especially for the asymmetric systems. For the symmetric and slightly asymmetric diblock copolymer systems, the confinement primarily affects the orientation of the lamellar domains and only marginally influences the domain morphologies. These systems form parallel lamellar phases with different number of lamellae, and perpendicular and mixed lamellar phases. In a narrow portion of the phase diagram, these systems exhibit a parallel perforated lamellar phase, where further insight into the appearance of this phase is provided through free-energy calculations. The confined highly asymmetric diblock copolymer system shows, in addition to nanostructures with parallel and perpendicular cylinders, noncylindrical structures such as parallel lamellae and parallel perforated lamellae. The formation of the various confined nanostructures is further analyzed by calculating structural characteristics such as the mean square end-to-end distance of the diblock copolymers and the nematic order parameter.
Collapse
Affiliation(s)
- Pavel Petrus
- Department of Physics, Faculty of Science, J. E. Purkinje University, Ustí n. Lab., Czech Republic
| | | | | |
Collapse
|
19
|
Petrus P, Lísal M, Brennan JK. Self-assembly of symmetric diblock copolymers in planar slits with and without nanopatterns: insight from dissipative particle dynamics simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3695-3709. [PMID: 19839566 DOI: 10.1021/la903200j] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present a dissipative particle dynamics simulation study on the formation of nanostructures of symmetric diblock copolymers confined between planar surfaces with and without nanopatterns. The nanopatterned surface is mimicked by alternating portions of the surface that interact differently with the diblock copolymers. The formation of the diblock-copolymer nanostructures confined between the planar surfaces is investigated and characterized by varying the separation width and the strength of the interaction between the surfaces and the diblock copolymers. For surfaces with nanopatterns, we also vary both the mutual area and location of the nanopatterns, where we consider nanopatterns on the opposing surfaces that are vertically (a) aligned, (b) staggered, and (c) partially staggered. In the case of planar slits without nanopatterns, we observe the formation of perpendicular and parallel lamellar phases with different numbers of lamellae. In addition, the symmetric diblock copolymers self-assemble into adsorbed layer and adsorbed layer-parallel lamellar phases and a mixed lamellar phase when the opposing surfaces of the planar slits are modeled by different types of wall beads. In the case of nanopatterned planar slits, we observe novel nanostructures and attempt to rationalize the diblock copolymer self-assembly on the basis of the behavior that we observed in the planar slits without nanopatterns. In particular, we investigate the applicability of predicting the structures formed in the nanopatterned slits by a superposition of the observed structures in slits without nanopatterns.
Collapse
Affiliation(s)
- Pavel Petrus
- Department of Physics, Faculty of Science, J. E. Purkinje University, Usti n. Lab., Czech Republic
| | | | | |
Collapse
|
20
|
Nyfors L, Suchy M, Laine J, Kontturi E. Ultrathin cellulose films of tunable nanostructured morphology with a hydrophobic component. Biomacromolecules 2009; 10:1276-81. [PMID: 19338348 DOI: 10.1021/bm900099e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In recent years, a wide range of different methods to implant nanosized patterns on surfaces have been developed. Spin coating immiscible binary polymer blends is a straightforward method to prepare micro- and nanostructures on thin films. This study utilizes binary blends to effortlessly prepare stable, surface-functionalized cellulose films. Blends of trimethylsilyl cellulose (TMSC) majority phase and polystyrene (PS) minority phase in toluene were spin coated into an ultrathin film, and TMSC was hydrolyzed to cellulose. The films were characterized and quantified using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, and quartz crystal microbalance (QCM-D). AFM revealed that horizontally phase-separated structures form during spin coating: after the hydrolyzation of TMSC to cellulose, PS protrudes from cellulose as distinct patches. The patches are disk-like structures with a circular radial cross-section and a height of ca. 5-20 nanometers. The smaller the amount of PS in the original spin coating solution, the smaller the PS island dimensions in the films. The results obtained from the XPS measurements support the AFM results. Water contact angle of the PS/cellulose films increases from 61 degrees to 71 degrees when the relative amount of hydrophobic PS is increased from 1:100 to 1:5. Thus by simply varying the ratio of the film components subtly tailored hydrophobic properties can be achieved. The swelling of the films due to exposure to water was studied by QCM-D. The swelling was not affected by the amount of PS in the blend, and at equivalent cellulose content the blends and pure cellulose films exhibited similar swelling characteristics. In addition, the QCM-D evaluation demonstrated that the films are stable over extended periods of time and are suitable for fundamental studies by QCM-D.
Collapse
Affiliation(s)
- Laura Nyfors
- Department of Forest Products Technology, Helsinki University of Technology, P.O. Box 6300, FIN-02015 TKK, Finland
| | | | | | | |
Collapse
|
21
|
Kriksin YA, Erukhimovich IY, Smirnova YG, Khalatur PG, ten Brinke G. Nonmonotonic incommensurability effects in lamellar-in-lamellar self-assembled multiblock copolymers. J Chem Phys 2009; 130:204901. [DOI: 10.1063/1.3138903] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
22
|
Pastorino C, Binder K, Müller M. Coarse-Grained Description of a Brush−Melt Interface in Equilibrium and under Flow. Macromolecules 2008. [DOI: 10.1021/ma8015757] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Pastorino
- Departamento de Fisica, Centro Atomico Constituyentes, CNEA-CONICET, Av. Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina; Institut für Physik WA331, Johannes Gutenberg-Universität, 55099 Mainz, Germany; and Institut für Theoretische Physik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - K. Binder
- Departamento de Fisica, Centro Atomico Constituyentes, CNEA-CONICET, Av. Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina; Institut für Physik WA331, Johannes Gutenberg-Universität, 55099 Mainz, Germany; and Institut für Theoretische Physik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - M. Müller
- Departamento de Fisica, Centro Atomico Constituyentes, CNEA-CONICET, Av. Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina; Institut für Physik WA331, Johannes Gutenberg-Universität, 55099 Mainz, Germany; and Institut für Theoretische Physik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| |
Collapse
|
23
|
Van Puyvelde P, Vananroye A, Cardinaels R, Moldenaers P. Review on morphology development of immiscible blends in confined shear flow. POLYMER 2008. [DOI: 10.1016/j.polymer.2008.08.055] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
24
|
De Virgiliis A, Vink RLC, Horbach J, Binder K. From capillary condensation to interface localization transitions in colloid-polymer mixtures confined in thin-film geometry. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:041604. [PMID: 18999436 DOI: 10.1103/physreve.78.041604] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Indexed: 05/27/2023]
Abstract
Monte Carlo simulations of the Asakura-Oosawa model for colloid-polymer mixtures confined between two parallel repulsive structureless walls are presented and analyzed in the light of current theories on capillary condensation and interface localization transitions. Choosing a polymer-to-colloid size ratio of q=0.8 and studying ultrathin films in the range of D=3 to D=10 colloid diameters thickness, grand canonical Monte Carlo methods are used; phase transitions are analyzed via finite size scaling, as in previous work on bulk systems and under confinement between identical types of walls. Unlike the latter work, inequivalent walls are used here: While the left wall has a hard-core repulsion for both polymers and colloids, at the right-hand wall an additional square-well repulsion of variable strength acting only on the colloids is present. We study how the phase separation into colloid-rich and colloid-poor phases occurring already in the bulk is modified by such a confinement. When the asymmetry of the wall-colloid interaction increases, the character of the transition smoothly changes from capillary condensation type to interface localization type. For very thin films (i.e., for D=3 ) and a suitable choice of the wall-colloid interactions, evidence is found that the critical behavior falls in the universality class of the two-dimensional Ising model. Otherwise, we observe crossover scaling between different universality classes (namely, the crossover from the three-dimensional to the two-dimensional Ising model universality class). The colloid and polymer density profiles across the film in the various phases are discussed, as well as the correlation of interfacial fluctuations in the direction parallel to the confining walls. The broadening of the interface between the coexisting colloid-rich and polymer-rich phases (located parallel to the confining walls) is understood in terms of capillary wave fluctuations. The experimental observability of all these phenomena is briefly discussed.
Collapse
Affiliation(s)
- Andres De Virgiliis
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz, Germany
| | | | | | | |
Collapse
|
25
|
Wang R, Chen YL, Hu J, Xue G. Depletion-induced surface alignment of asymmetric diblock copolymer in selective solvents. J Chem Phys 2008; 129:044907. [DOI: 10.1063/1.2957746] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
26
|
Binder K, Horbach J, Vink R, De Virgiliis A. Confinement effects on phase behavior of soft matter systems. SOFT MATTER 2008; 4:1555-1568. [PMID: 32907146 DOI: 10.1039/b802207k] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
When systems that can undergo phase separation between two coexisting phases in the bulk are confined in thin film geometry between parallel walls, the phase behavior can be profoundly modified. These phenomena shall be described and exemplified by computer simulations of the Asakura-Oosawa model for colloid-polymer mixtures, but applications to other soft matter systems (e.g. confined polymer blends) will also be mentioned. Typically a wall will prefer one of the phases, and hence the composition of the system in the direction perpendicular to the walls will not be homogeneous. If both walls are of the same kind, this effect leads to a distortion of the phase diagram of the system in thin film geometry, in comparison with the bulk, analogous to the phenomenon of "capillary condensation" of simple fluids in thin capillaries. In the case of "competing walls", where both walls prefer different phases of the two phases coexisting in the bulk, a state with an interface parallel to the walls gets stabilized. The transition from the disordered phase to this "soft mode phase" is rounded by the finite thickness of the film and is not a sharp phase transition. However, a sharp transition can occur where this interface gets localized at (one of) the walls. The relation of this interface localization transition to wetting phenomena is discussed. Finally, an outlook to related phenomena is given, such as the effects of confinement in cylindrical pores on the phase behavior, and more complicated ordering phenomena (lamellar mesophases of block copolymers or nematic phases of liquid crystals under confinement).
Collapse
Affiliation(s)
- Kurt Binder
- Institut für Physik, Johannes Gutenberg Universität Mainz, Staudinger Weg 7, 55099 Mainz, Germany.
| | - Jürgen Horbach
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 51170 Köln, Germany.
| | - Richard Vink
- Institut für Theoretische Physik, Georg-August Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
| | - Andres De Virgiliis
- Instituto de Investigaciones Fisicoquimicas, UNLP, CONICET, Sucursal 4, Casilla de Correo 16, 1900 La Plata, Argentina.
| |
Collapse
|
27
|
Sevink GJA, Zvelindovsky AV. Block copolymers confined in a nanopore: Pathfinding in a curving and frustrating flatland. J Chem Phys 2008; 128:084901. [DOI: 10.1063/1.2829406] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
28
|
Liao Y, You J, Shi T, An L, Dutta PK. Phase behavior and dewetting for polymer blend films studied by in situ AFM and XPS: from thin to ultrathin films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:11107-11. [PMID: 17894511 DOI: 10.1021/la701761p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In this work, the film thickness (l0) effect on the phase and dewetting behaviors of the blend film of poly(methyl methacrylate)/poly(styrene-ran-acrylonitrile) (PMMA/SAN) has been studied by in situ atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The thinner film shows the more compatibility of the blend, and the phase separation of the film occurs at l0>5Rg (radius of gyration). An initially time-independent q*, the characteristic wavenumber of the phase image, which is in good agreement of Cahn's linearized theory for the early stage of spinodal decomposition, has been obtained in real space and discussed in detail. For 5Rg>l0>3Rg, a "pseudo-dewetting/(phase separation+wetting)" behavior occurs, where the pseudo-wetting is driven by the concentration fluctuation mechanism. For l0<3Rg, a "real dewetting/(phase separation+wetting)" behavior occurs.
Collapse
Affiliation(s)
- Yonggui Liao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | | | | | | | | |
Collapse
|
29
|
Eurich F, Karatchentsev A, Baschnagel J, Dieterich W, Maass P. Soft particle model for block copolymers. J Chem Phys 2007; 127:134905. [DOI: 10.1063/1.2787007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
30
|
Song J, Li Y, Huang Q, Shi T, An L. Monte Carlo simulation on symmetric ABA/AB copolymer blends in confined thin films. J Chem Phys 2007; 127:094903. [PMID: 17824761 DOI: 10.1063/1.2764071] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effects of blend composition on morphology, order-disorder transition (ODT), and chain conformation of symmetric ABA/AB copolymer blends confined between two neutral hard walls have been investigated by lattice Monte Carlo simulation. Only lamellar structure is observed in all the simulation morphologies under thermodynamic equilibrium state, which is supported by theoretical prediction. When the composition of AB diblock copolymer (phi) increases, both lamellar spacing and the corresponding ODT temperature increase, which can be attributed to the variation of conformation distribution of the diblock and the triblock copolymer chains. In addition, both diblock and triblock copolymer, chains with bridge conformation extend dramatically in the direction parallel to the surface when the system is in ordered state. Finally, the copolymer chain conformation depends strongly on both the blend composition and the incompatibility parameter chiN.
Collapse
Affiliation(s)
- Jianhui Song
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Peoples' Republic of China
| | | | | | | | | |
Collapse
|
31
|
Pastorino C, Kreer T, Müller M, Binder K. Comparison of dissipative particle dynamics and Langevin thermostats for out-of-equilibrium simulations of polymeric systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:026706. [PMID: 17930173 DOI: 10.1103/physreve.76.026706] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 06/07/2007] [Indexed: 05/12/2023]
Abstract
In this work we compare and characterize the behavior of Langevin and dissipative particle dynamics (DPD) thermostats in a broad range of nonequilibrium simulations of polymeric systems. Polymer brushes in relative sliding motion, polymeric liquids in Poiseuille and Couette flows, and brush-melt interfaces are used as model systems to analyze the efficiency and limitations of different Langevin and DPD thermostat implementations. Widely used coarse-grained bead-spring models under good and poor solvent conditions are employed to assess the effects of the thermostats. We considered equilibrium, transient, and steady state examples for testing the ability of the thermostats to maintain constant temperature and to reproduce the underlying physical phenomena in nonequilibrium situations. The common practice of switching off the Langevin thermostat in the flow direction is also critically revisited. The efficiency of different weight functions for the DPD thermostat is quantitatively analyzed as a function of the solvent quality and the nonequilibrium situation.
Collapse
Affiliation(s)
- C Pastorino
- Departamento de Física, Centro Atómico Constituyentes, CNEA/CONICET, Av. Gral. Paz 1499, 1650 Provincia de Buenos Aires, Argentina
| | | | | | | |
Collapse
|
32
|
Miao B, Yan D, Wickham RA, Shi AC. The nature of phase transitions of symmetric diblock copolymer melts under confinement. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.05.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
33
|
Yu B, Sun P, Chen T, Jin Q, Ding D, Li B, Shi AC. Self-assembled morphologies of diblock copolymers confined in nanochannels: Effects of confinement geometry. J Chem Phys 2007; 126:204903. [PMID: 17552796 DOI: 10.1063/1.2735626] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The self-assembly of diblock copolymers confined in channels of various shaped cross sections is studied using a simulated annealing technique with the "single-site bond fluctuation" model. In the bulk, the asymmetric diblock copolymers used in this study form hexagonally packed cylinders with period L0. The cross sections of the confining channels are of different shapes including regular triangles, rectangles, squares, regular hexagons, regular octagons, and ellipses. For a given geometry, the channel size (characterized by one or two lengths) is varied from very small to several times of L0. It is found that the geometry and size of the confining channels have a large effect on the structure and symmetry of the self-assembled morphologies. Multiple packed cylinders with the symmetry of the confining channels are the major morphologies for low-symmetry cross sections such as triangle, rectangle, and square. More complex structures such as helices or stacked toroids spontaneously form when the confining channels are shaped such as a regular hexagon, a regular octagon, or an ellipse. The domain spacing of the self-assembled structures can be altered by the shape and size of the confining channels. Our results are consistent with available experiments. These results indicate that the self-assembled structures of block copolymers can be manipulated by the shape of the confining channels.
Collapse
Affiliation(s)
- Bin Yu
- College of Physics, Nankai University, Tianjin 300071, China
| | | | | | | | | | | | | |
Collapse
|
34
|
Alexander-Katz A, Fredrickson GH. Diblock Copolymer Thin Films: A Field-Theoretic Simulation Study. Macromolecules 2007. [DOI: 10.1021/ma070005h] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alfredo Alexander-Katz
- Physics Department, Technical University of Munich, D-80538, Garching, Germany, and Department of Physics, Department of Chemical Engineering, and Materials Research Laboratory, University of California, Santa Barbara, California 93106
| | - Glenn H. Fredrickson
- Physics Department, Technical University of Munich, D-80538, Garching, Germany, and Department of Physics, Department of Chemical Engineering, and Materials Research Laboratory, University of California, Santa Barbara, California 93106
| |
Collapse
|
35
|
Ye Z, Chen H, Liu H, Hu Y, Jiang J. Density functional theory for copolymers confined in a nanoslit. J Chem Phys 2007; 126:134903. [PMID: 17430063 DOI: 10.1063/1.2713378] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A density functional theory is developed for copolymers confined in a nanoslit on the basis of our previous work for homopolymers. The theory accurately captures the structural characteristics for diblock and alternating copolymers composed of hard-sphere or square-well segments. Satisfactory agreement is obtained between the theoretical predictions and simulation results in segment density profiles, segment fractions, and partition coefficients. Structures under confinement strongly depend on the substituent segment sizes for the hard-sphere copolymers and also on the segment-wall attractions for the square-well copolymers. Alternating copolymers are found to behave as homopolymers with effective segment size, and effective segment-segment and segment-wall interactions.
Collapse
Affiliation(s)
- Zhencheng Ye
- State Key Laboratory of Chemical Engineering, and Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China
| | | | | | | | | |
Collapse
|
36
|
Patra CN. Effect of attractions on the structure of polymer solutions confined between surfaces: A density functional approach. J Chem Phys 2007; 126:074905. [PMID: 17328632 DOI: 10.1063/1.2567271] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A density functional theory is presented to study the effect of attractions on the structure of polymer solutions confined between surfaces. The polymer molecules have been modeled as a pearl necklace of freely jointed hard spheres and the solvent as hard spheres, both having Yukawa-type attractions and the mixture being confined between attractive Yukawa-type surfaces. The present theory treats the ideal gas free energy functional exactly and uses weighted density approximation for the hard chain and hard sphere contributions to the excess free energy functional. The attractive interactions are calculated using the direct correlation function obtained from the polymer reference interaction site model theory along with the mean spherical approximation closure. The theoretical predictions on the density profiles of the polymer and the solvent molecules are found to agree quite well with the Monte Carlo simulation results for varying densities, chain lengths, wall separations, and different sets of interaction potentials.
Collapse
Affiliation(s)
- Chandra N Patra
- Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400 085, India.
| |
Collapse
|
37
|
Sferrazza M, Carelli C. Interfaces and fluctuations in confined polymeric liquid mixtures: from immiscible to near critical systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2007; 19:073102. [PMID: 22251583 DOI: 10.1088/0953-8984/19/7/073102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this paper the structure of the interface between polymer films is discussed to elucidate fluctuations and confinement effects in fluid polymer mixtures. The neutron reflectivity technique has been employed to investigate the dependence of the structure of the interface on the degree of immiscibility of the polymers over a wide range, as criticality is approached, and to characterize it in terms of intrinsic width, as calculated by mean field theories, and capillary fluctuations. For more immiscible systems, as the degree of incompatibility between the polymers is decreased, the width of the interface increases slowly, and it is independent of the molecular weight of the polymers. Closer to the critical point the dependence on the degree of miscibility becomes stronger and the way in which the interfacial width diverges, as criticality is approached, is related to both chain length and Flory-Huggins interaction parameter (χ). The results have been compared to the predictions of mean field theories. Self-consistent field numerical calculations, with the additional contribution due to capillary waves, provide a good description of the width of the interface between two polymer bulk phases, in particular at higher and intermediate degrees of immiscibility-the product of the Flory-Huggins interaction parameter χ and the number N of monomers of the chain, χN. For more miscible systems a crossover is observed to a region where the square gradient theory in the weak segregation limit better approximates the experimental results. Moreover, the mechanisms by which confinement affects the interface have been investigated. To understand the relative importance of the long ranged van der Waals forces and short ranged 'truncation forces' in modifying thermally excited fluctuations at the polymer/polymer interface, the thickness dependence of the interfacial width has been studied for different degrees of miscibility, approaching criticality. The results show a gradual transition from a region where long ranged dispersion forces are dominant in influencing the capillary wave spectrum, for higher degrees of immiscibility, to a region where short ranged forces-connected to the presence of the walls-become more important and the dependence of the interfacial width on film thickness is stronger. The thickness dependence of the interfacial width was also studied for systems with different molecular weights in different conditions of miscibility, to investigate the effects of a confined geometry on polymers with different chain lengths as criticality is approached.
Collapse
Affiliation(s)
- Michele Sferrazza
- Département de Physique, Université Libre de Bruxelles, Boulevard du Triomphe CP223, 1050 Bruxelles, Belgium.
| | | |
Collapse
|
38
|
Andrew P, Huck WTS. Polymer phase separation on lattice patterned surfaces. SOFT MATTER 2007; 3:230-237. [PMID: 32680270 DOI: 10.1039/b613593e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We demonstrate the self-organization of phase-separated polymer microstructures on two-dimensionally chemically patterned surfaces. Pattern replication is expected when both the blend composition ratio matches the surface patterning area ratio, and the pattern periodicity matches the natural phase separation length scale. By varying film thickness and blend composition, we show that ordered morphologies also result for contrary situations, resulting in the formation of a rich variety of hierarchically-ordered microstructures. This hierarchy suggests that non-equilibrium structures generated by incomplete phase separation of blend components are locked in by rapid solvent quenching during casting.
Collapse
Affiliation(s)
- Piers Andrew
- The Nanoscience Centre, University of Cambridge, 11 J. J. Thomson Avenue, Cambridge, UKCB3 0FF.
| | - Wilhelm T S Huck
- The Nanoscience Centre, University of Cambridge, 11 J. J. Thomson Avenue, Cambridge, UKCB3 0FF. and Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UKCB2 1EW.
| |
Collapse
|
39
|
Wang Q. Symmetric diblock copolymers in nanopores: Monte Carlo simulations and strong-stretching theory. J Chem Phys 2007; 126:024903. [PMID: 17228969 DOI: 10.1063/1.2406078] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have performed lattice Monte Carlo simulations to study the self-assembled morphology of symmetric diblock copolymers in nanopores. The pore diameter and surface preference are systematically varied to examine their effects on the chain conformations, structures of various morphologies, and their phase transition. Various ensemble-averaged profiles and quantities are used to provide detailed information about the system. The simulation results are also compared with the predictions of a strong-stretching theory commonly used in the literature. Such comparisons reveal the deficiencies of this theory in describing the morphologies under cylindrical confinement, and call for further theoretical studies using more accurate formalisms.
Collapse
Affiliation(s)
- Qiang Wang
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, Colorado 80523-1370, USA.
| |
Collapse
|
40
|
Jaczewska J, Budkowski A, Bernasik A, Raptis I, Raczkowska J, Goustouridis D, Rysz J, Sanopoulou M. Humidity and solvent effects in spin-coated polythiophene–polystyrene blends. J Appl Polym Sci 2007. [DOI: 10.1002/app.26012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
41
|
|
42
|
Pastorino C, Binder K, Kreer T, Müller M. Static and dynamic properties of the interface between a polymer brush and a melt of identical chains. J Chem Phys 2006; 124:64902. [PMID: 16483239 DOI: 10.1063/1.2162883] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Molecular-dynamics simulations of a short-chain polymer melt between two brush-covered surfaces under shear have been performed. The end-grafted polymers which constitute the brush have the same chemical properties as the free chains in the melt and provide a soft deformable substrate. Polymer chains are described by a coarse-grained bead-spring model, which includes excluded volume and backbone connectivity of the chains. The grafting density of the brush layer offers a way of controlling the behavior of the surface without altering the molecular interactions. We perform equilibrium and nonequilibrium molecular-dynamics simulations at constant temperature and volume using the dissipative particle dynamics thermostat. The equilibrium density profiles and the behavior under shear are studied as well as the interdigitation of the melt into the brush, the orientation on different length scales (bond vectors, radius of gyration, and end-to-end vector) of free and grafted chains, and velocity profiles. The obtained boundary conditions and slip length show a rich behavior as a function of grafting density and shear velocity.
Collapse
Affiliation(s)
- C Pastorino
- Institut für Physik WA331, Johannes Gutenberg-Universität, Mainz, Germany.
| | | | | | | |
Collapse
|
43
|
Wu J. Density functional theory for chemical engineering: From capillarity to soft materials. AIChE J 2006. [DOI: 10.1002/aic.10713] [Citation(s) in RCA: 299] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
44
|
Nie Z, Su Z, Sun Z, Shi T, An L. Conformational Study on Thin Films of Symmetric AnB2nAn Triblock Copolymer. MACROMOL THEOR SIMUL 2005. [DOI: 10.1002/mats.200500042] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
45
|
Raczkowska J, Cyganik P, Budkowski A, Bernasik A, Rysz J, Raptis I, Czuba P, Kowalski K. Composition Effects in Polymer Blends Spin-Cast on Patterned Substrates. Macromolecules 2005. [DOI: 10.1021/ma051242s] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. Raczkowska
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - P. Cyganik
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - A. Budkowski
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - A. Bernasik
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - J. Rysz
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - I. Raptis
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - P. Czuba
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| | - K. Kowalski
- M. Smoluchowski Institute of Physics and Joint Center for Chemical Analysis and Structural Research, Jagellonian University, Reymonta 4, 30-059 Kraków, Poland; Faculty of Physics and Applied Computer Science and Faculty of Metallurgy and Materials Science, AGH−University of Science and Technology, Mickiewicza 39, 30-059 Kraków, Poland; and Institute of Microelectronics, NCRS “Demokritos”, 15310 Aghia Paraskevi, Greece
| |
Collapse
|
46
|
Li Z, Cao D, Wu J. Layering, condensation, and evaporation of short chains in narrow slit pores. J Chem Phys 2005; 122:224701. [PMID: 15974697 DOI: 10.1063/1.1924603] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The phase behavior of short-chain fluids in slit pores is investigated by using a nonlocal-density-functional theory that takes into account the effects of segment size, chain connectivity, and van der Waals attractions explicitly. The layering and capillary condensation/evaporation transitions are examined at different chain length, temperature, pore width, and surface energy. It is found that longer chains are more likely to show hysteresis loops and multilayer adsorptions along with the capillary condensation and evaporation. Decreasing temperature favors the inclusion of layering transitions into the condensation/evaporation hysteresis loops. For large pores, the surface energy has relatively small effect on the pressures of the capillary condensation and evaporation but affects significantly on the layering pressures. It is also observed that all phase transitions within the pore take place at pressures lower than the corresponding bulk saturation pressure. The critical temperature of condensation/evaporation is always smaller than that of the bulk fluid. All coexistence curves for confined phase transitions are contained within the corresponding bulk vapor-liquid coexistence curve. As in the bulk phase, the longer the chain length, the higher are the critical temperatures of phase transitions in the pore.
Collapse
Affiliation(s)
- Zhidong Li
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521-0425, USA
| | | | | |
Collapse
|
47
|
Reister E, Müller M, Kumar SK. Equilibrium Phase Behavior of Polybutadiene/Polyisoprene Films: Binodals and Spinodals. Macromolecules 2005. [DOI: 10.1021/ma0473465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ellen Reister
- II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany
| | - Marcus Müller
- Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706-1390
| | - Sanat K. Kumar
- Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180
| |
Collapse
|
48
|
Fraser B, Denniston C, Müser MH. Diffusion, elasticity, and shear flow in self-assembled block copolymers: A molecular dynamics study. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/polb.20387] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
49
|
Ludwigs S, Schmidt K, Krausch G. One-Dimensional Swelling of a pH-Dependent Nanostructure Based on ABC Triblock Terpolymers. Macromolecules 2005. [DOI: 10.1021/ma047812q] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabine Ludwigs
- Physikalische Chemie II and Bayreuther Zentrum für Kolloide und Grenzflächen (BZKG), Universität Bayreuth, D-95440 Bayreuth, Germany
| | - Kristin Schmidt
- Physikalische Chemie II and Bayreuther Zentrum für Kolloide und Grenzflächen (BZKG), Universität Bayreuth, D-95440 Bayreuth, Germany
| | - Georg Krausch
- Physikalische Chemie II and Bayreuther Zentrum für Kolloide und Grenzflächen (BZKG), Universität Bayreuth, D-95440 Bayreuth, Germany
| |
Collapse
|
50
|
Ludwigs S, Krausch G, Magerle R, Zvelindovsky AV, Sevink GJA. Phase Behavior of ABC Triblock Terpolymers in Thin Films: Mesoscale Simulations. Macromolecules 2005. [DOI: 10.1021/ma049047l] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|