Polymer Brushes in a Poor Solvent

Soga, Kazuo; Guo, Hong; Zuckermann, Martin J.

doi:10.1209/0295-5075/29/7/004

Cited by 81 publications

(72 citation statements)

References 11 publications

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“…Scaling Relations and Distribution Functions subsection) do not depend on the numerical value of w 2 . In accordance with the choice made in our previous studies, [17][18][19][20] we use the value w 2 ϭ 0.5 in our simulations.…”

Section: Model and Simulation Methodsmentioning

confidence: 99%

“…Estimates for the scaling exponents of the Domb-Joyce model are known from a field-theoretic analysis of high-precision MC data. 15,16 Recently we used discretized Edwards chains in conjunction with off-lattice Monte Carlo simulation schemes for a variety of polymer systems including grafted polymer brushes in a good solvent 17 as well as in a poor solvent, 18 binary brushes in both good and poor solvent, 19 polymer brushes in a good solvent under shear, 20 and diblock copolymer melts. 21,22 The characteristic feature of the models used in these studies is that the volume interaction is formulated as a "virial expansion" in terms of coarse-grained number densities of the effective chain monomers ("vertices").…”

Section: Introductionmentioning

confidence: 99%

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Off-lattice Monte Carlo simulation of the discrete Edwards model

Besold

Guo

Zuckermann

2000

J. Polym. Sci. B Polym. Phys.

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Section: Model and Simulation Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Off-lattice Monte Carlo simulation of the discrete Edwards model

Besold

Guo

Zuckermann

2000

J. Polym. Sci. B Polym. Phys.

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“…Early research on single-component linear homopolymers grafted onto planar substrates predicted and confirmed one domain pattern; small circular clusters of the grafted polymers [7][8][9][10][11][12][13]. These clusters are distributed on the substrate and are referred to as pinned micelles.…”

mentioning

confidence: 95%

Molecular simulation of 2-dimensional microphase separation of single-component homopolymers grafted onto a planar substrate

Norizoe

Jinnai

Takahara

2013

EPL

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-The structural phase behavior of polymer brushes, single-component linear homopolymers grafted onto a planar substrate, is studied using the molecular Monte Carlo method in 3 dimensions. When simulation parameters of the system are set in regions of macrophase separation of solution for the corresponding nongrafted homopolymers, the grafted polymers also prefer segregation. However, macrophase separation is disallowed due to the spatially-fixed grafting points of the polymers. Such constraints on the grafting are similar to connecting points between blocks of non-grafted diblock copolymers at the microphase separation in the melt state. This results in "microphase separation" of the homopolymer brush in the lateral direction of the substrate. Here we extensively search the parameter space and reveal various lateral domain patterns that are similar to those found in diblock copolymer melts at microphase separation.Polymer chains grafted onto substrates, i.e. polymer brushes, have been extensively studied in physics, chemistry, materials science, and other scientific and industrial fields. Polymer brushes are widely utilized for applications such as wetting, adhesion, surface patterning, and colloidal stabilization. Recently, sophisticated polymer brushes, such as brushes composed of diblock copolymers and of binary mixture of homopolymers, have drawn significant attention [1,2]. Polymer brushes on spherical substrates, which are referred to as polymer-grafted colloidal particles, have also attracted wide interest in various scientific and industrial fields [3][4][5].The phase behavior of these complicated brushes is significantly dependent on the molecular architecture, shape of the substrate, ratios between the numbers of polymers of each polymer species, and other characteristics of each system. In the present work, the most basic and simplest polymer brush, i.e. single-component linear homopolymers homogeneously grafted onto a planar substrate, is simulated using the molecular Monte Carlo method to determine the universal and structural phase behavior of polymer brushes.The phase behavior of a solution of single-component nongrafted homopolymers underlies the phase behavior of the present brush. When the chemical and physical parameters of this polymer solution are set in regions within binodal lines of the phase diagram, the non-grafted polymers are segregated into a low-density domain and a high-density domain, which indicates macrophase separation. When the parameters of a layer of the grafted polymers are set in these regions within the binodal lines of the non-grafted polymers, the grafted polymers also prefer segregation. However, due to a topological constraint of the spatially-fixed grafting points of each polymer, macrophase separation of the grafted polymers is disallowed. This constraint has similarity to the topological constraint of connecting points between blocks of non-grafted diblock copolymers at phase separation in the melt state. These non-grafted diblock copolymers exhibit microp...

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“…In contrast, good solvents can induce, at low surface coverages, a structure resembling that of the free polymer chains in solution (mushroom structure), or, at high coverages, a significant stretching of the polymers leading to a polymer brush. Several studies have been conducted to understand the effect of solvent quality on the structure and stability of brushes [18,19]. The structural changes and preferential solvation of polymer brushes have been studied in detail [20][21][22] by varying the solvent quality using binary solutions, which contain varying volume fractions of good and bad solvents in the solution.…”

Section: Introductionmentioning

confidence: 99%

Macrotribological Studies of Poly(L-lysine)-graft-Poly(ethylene glycol) in Aqueous Glycerol Mixtures

et al. 2009

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We have investigated the tribological properties of surfaces with adsorbed poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) sliding in aqueous glycerol solutions under different lubrication regimes. Glycerol is a polar, biocompatible liquid with a significantly higher viscosity than that of water. Macrotribological performance was investigated by means of pin-on-disk and mini-tractionmachine measurements in glycerol-PLL-g-PEG-aqueous buffer mixtures of varying compositions. Adsorption studies of PLL-g-PEG from these mixtures were conducted with the quartz-crystal-microbalance technique. The enhanced viscosity of the glycerol-containing lubricant reduces the coefficient of friction due to increased hydrodynamic forces, leading to a more effective separation of the sliding partners, while the presence of hydrated polymer brushes at the interface leads to an entropically driven repulsion, which also helps mitigate direct asperity-asperity contact between the solid surfaces under boundary-lubrication conditions. The combination of polymer layers on surfaces with aqueous phases of enhanced viscosity thus enables the friction to be reduced by several orders of magnitude, compared to the behavior of pure water, over a large range of sliding speeds. The individual contributions of the polymer and the aqueous glycerol solutions in reducing the friction have been studied across different lubrication regimes.

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Polymer Brushes in a Poor Solvent

Cited by 81 publications

References 11 publications

Off-lattice Monte Carlo simulation of the discrete Edwards model

Off-lattice Monte Carlo simulation of the discrete Edwards model

Molecular simulation of 2-dimensional microphase separation of single-component homopolymers grafted onto a planar substrate

Macrotribological Studies of Poly(L-lysine)-graft-Poly(ethylene glycol) in Aqueous Glycerol Mixtures

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