A Free Energy Model for Confined Diblock Copolymers

Walton, D. G.; Kellogg, G. J.; Mayes, Anne M.; Lambooy, P.; Russell, Thomas P.

doi:10.1021/ma00099a045

Cited by 298 publications

(415 citation statements)

References 8 publications

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“…Thin films have been studied extensively by experiments [5][6][7][8][9][10][11][12][13][14][15] and theory. [16][17][18][19][20][21] In these films the microdomains have a lamellar shape as in a bulk system. The lamellae align parallel with the film, when a difference between the surface energies of the two blocks exists ͑selective interfaces͒.…”

Section: A Block Copolymer Thin Filmsmentioning

confidence: 95%

“…This behavior has already been predicted for symmetric block copolymers confined in a slit with selective surfaces. 18,21 Parallel lamellae are formed at nearly all values of H, but at certain widths perpendicular lamellae are more stable.…”

Section: Phase Behavior In a Slitmentioning

confidence: 98%

“…In unconfined films, terraces are formed with a step height of about the equilibrium lamellar period in the bulk, because the thickness of a homogeneous film is not commensurate with an integer amount of lamellae without frustrating the lamellar period. 6,7,18,19,20 In confined films, frustration cannot be avoided and the lamellar period deviates from the bulk value. 13,16 Random copolymers have been used to tune the interactions between the interfaces and the two different copolymer blocks.…”

Section: A Block Copolymer Thin Filmsmentioning

confidence: 99%

“…Therefore, parallel cylinders are unstable compared to perpendicular cylinders for nearly every value of H. Again, the A 3 B 6 polymer has the same behavior as a symmetric diblock copolymer. 18 Table I. TABLE I.…”

Section: Phase Behavior In a Slitmentioning

confidence: 99%

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Asymmetric block copolymers confined in a thin film

Huinink

Brokken-Zijp

Dijk

et al. 2000

The Journal of Chemical Physics

185

318

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We have used a dynamic density functional theory ͑DDFT͒ for polymeric systems, to simulate the formation of micro phases in a melt of an asymmetric block copolymer, A n B m ( f A ϭ1/3), both in the bulk and in a thin film. In the DDFT model a polymer is represented as a chain of springs and beads. A spring mimics the stretching behavior of a chain fragment and the spring constant is calculated with the Gaussian chain approximation. Simulations were always started from a homogeneous system. We have mainly investigated the final morphology, adopted by the system. First, we have studied the bulk behavior. The diblock copolymer forms a hexagonal packed array of A-rich cylinders, embedded in a B-rich matrix. Film calculations have been done by confining a polymer melt in a slit. Both the slit width and surface-polymer interactions were varied. With the outcomes a phase diagram for confined films has been constructed. Various phases are predicted: parallel cylinders (C ʈ ), perpendicular cylinders (C Ќ ), parallel lamellae (L ʈ ), and parallel perforated lamellae (CL ʈ ). When the film surfaces are preferentially wet by either the A or the B block, parallel oriented microdomains are preferred. A perpendicular cylindrical phase is stable when neither the A nor B block preferentially wets the surfaces. The predicted phase diagram is in accordance with experimental data in the literature and explains the experimentally observed differences between films of asymmetric block copolymers with only two parameters: the film thickness and the energetic preference of the surface for one of the polymer blocks. We have also observed, that confinement speeds up the process of long range ordering of the microdomains.

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Section: A Block Copolymer Thin Filmsmentioning

confidence: 95%

Section: Phase Behavior In a Slitmentioning

confidence: 98%

Section: A Block Copolymer Thin Filmsmentioning

confidence: 99%

Section: Phase Behavior In a Slitmentioning

confidence: 99%

See 2 more Smart Citations

Asymmetric block copolymers confined in a thin film

Huinink

Brokken-Zijp

Dijk

et al. 2000

The Journal of Chemical Physics

185

318

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“…8 Matsen attributed this behavior to the existence of a negative line tension where the A -B interfaces intersect the surfaces. 9 For the case of two identical surfaces with preferential surface-block interactions ͑symmetric surfaces͒, [8][9][10][11][12][13] parallel symmetric lamellae ͑configurations with an integer number of bilayers͒ and perpendicular lamellae with the bulk period have been predicted theoretically, depending on the extent of frustration between D and L 0 and the strength of the surface preference. If the surface preference is weak, perpendicular lamellae occur when parallel symmetric lamellae are least favorable as the frustration between D and L 0 increases.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo simulations of diblock copolymer thin films confined between two homogeneous surfaces

Wang

Yan

Nealey

et al. 2000

The Journal of Chemical Physics

158

216

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Thin films of symmetric diblock copolymers confined between two hard, flat and homogeneous surfaces have been investigated by means of Monte Carlo simulations on a simple cubic lattice. For such simulations, the match between bulk lamellar period L 0 and the simulation box size is crucial to obtain meaningful results. The simulations have been performed in an expanded grand-canonical ensemble, where the chemical potential and the temperature of the confined films are specified and the density is allowed to fluctuate. The dependence of morphology, density, and chain conformation in the confined films on the type of surfaces, surface separation, and the strength of surface-block interactions has been studied systematically. Our results are consistent with experimental findings.

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Block copolymer films on patterned surfaces

Chen¹

1998

J. Polym. Sci. B Polym. Phys.

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We present results from a numerical study of a coarse‐grained model of diblock copolymer (BCP) thin films cast on a chemically patterned surface. The patterned surface contains chemical inhomogeneities with a repeat spacing length scale comparable to the linear size of the BCP molecules. We find that the orientation of the lamellae in the thin film and the overlap of the film morphology with the preassigned surface pattern is strongly influenced by the commensurability between the bulk unconstrained lamellar size λ*, and the linear size of the surface inhomogeneities w. PACS Numbers: 64.60.Cn, 61.41.+e, 64.60.My, 64.75.+g. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 3127–3136, 1998

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A Free Energy Model for Confined Diblock Copolymers

Cited by 298 publications

References 8 publications

Asymmetric block copolymers confined in a thin film

Asymmetric block copolymers confined in a thin film

Monte Carlo simulations of diblock copolymer thin films confined between two homogeneous surfaces

Block copolymer films on patterned surfaces

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