Wetting in a phase separating polymer blend film: Quench depth dependence

Geoghegan, Mark; Ermer, Hubert; Jüngst, Gerald; Krausch, Georg; Brenn, R.

doi:10.1103/physreve.62.940

Cited by 68 publications

(66 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, recent experiments have observed the wetting transition in binary polymer blends. [52,53] TABLE I. Compilation of the boundaries of the different regimes in the vicinity of the tricritical point and the correlation lengths at the crossover. The latter quantity gives an estimate of the system size required to observe the crossover in the Monte Carlo simulations.…”

Section: Summary and Discussionmentioning

confidence: 99%

Interface localization-delocalization transition in a symmetric polymer blend: A finite-size scaling Monte Carlo study

Müller

Binder

2001

Phys. Rev. E

View full text Add to dashboard Cite

Using extensive Monte Carlo simulations we study the phase diagram of a symmetric binary (AB) polymer blend confined into a thin film as a function of the film thickness D. The monomerwall interactions are short ranged and antisymmetric, i.e, the left wall attracts the A-component of the mixture with the same strength as the right wall the B-component, and give rise to a first order wetting transition in a semi-infinite geometry. The phase diagram and the crossover between different critical behaviors is explored. For large film thicknesses we find a first order interface localisation/delocalisation transition and the phase diagram comprises two critical points, which are the finite film width analogies of the prewetting critical point. Using finite size scaling techniques we locate these critical points and present evidence of 2D Ising critical behavior. When we reduce the film width the two critical points approach the symmetry axis φ = 1/2 of the phase diagram and for D ≈ 2Rg we encounter a tricritical point. For even smaller film thickness the interface localisation/delocalisation transition is second order and we find a single critical point at φ = 1/2.Measuring the probability distribution of the interface position we determine the effective interaction between the wall and the interface. This effective interface potential depends on the lateral system size even away from the critical points. Its system size dependence stems from the large but finite correlation length of capillary waves. This finding gives direct evidence for a renormalization of the interface potential by capillary waves in the framework of a microscopic model.

show abstract

Section: Summary and Discussionmentioning

confidence: 99%

Interface localization-delocalization transition in a symmetric polymer blend: A finite-size scaling Monte Carlo study

Müller

Binder

2001

Phys. Rev. E

View full text Add to dashboard Cite

show abstract

“…Different laws for the temporal growth of the surface layer (defined by the first zero of the composition wave) have been identified and attributed to different mechanisms. The commonly observed t 1/3 behaviour [10,13,14,18,29,30] is related to the Lifshitz-Slyozov [35] (bulk) mechanism applied to the surface layer which ripens at the expense of bulk domains [2]. It was argued [4,30] that the experimental t 1/3 evidence corresponds to the surface partially wetted by droplets of the preferred phase, whereas the observed logarithmic [29,30] and t 1/2 [30] growths are characteristic of the continuous surface wetting layer.…”

Section: Introductionmentioning

confidence: 93%

Hydrodynamic-flow-driven phase evolution in a polymer blend film modified by diblock copolymers

Rysz

Ermer

Budkowski

et al. 2001

The European Physical Journal E

View full text Add to dashboard Cite

We have studied surface-directed phase separation in thin films of deuterated polystyrene and poly(bromostyrene) (with 22.7% of monomers brominated) using 3 He nuclear reaction analysis, dynamic secondary ion mass spectroscopy and atomic force microscopy combined with preferential dissolution. The crossover from competing to neutral surfaces of the critical blend film (cast onto Au) was commenced: polyisoprene-polystyrene diblock copolymers were added and segregated to both surfaces reducing in a tuneable manner the effective interactions. Two main stages of phase evolution are characterised by i) the growth of two surface layers and by ii) the transition from the four-layer to the final bilayer morphology. For increasing copolymer content the kinetics of the first stage is hardly affected but the amplitude of composition oscillations is reduced indicating more fragmented inner layers. As a result, a faster mass flow to the surfaces and an earlier completion of the second stage were observed. The hydrodynamic flow mechanism, driving both stages, is evidenced by nearly linear growth of the surface layer and by mass flow channels extending from the surface layer into the bulk. The final bilayer structure, formed even for the surfaces covered by strongly overlapped copolymers, is indicative of long-range (antisymmetric) surface forces.PACS. 64.75.+g Solubility, segregation, and mixing; phase separation -68.55.-a Thin film structure and morphology

show abstract

“…For homogeneous substrates simple strategies have been frequently used to alter the phase separation process by coarse modification of γ (e.g. by exchanging polymers [51,56]) or ∆γ (e.g. by changing the chemical nature of the substrate [9,11] Approaches using mixed SAMs [67] or end-grafted random copolymer brushes [68], both with variable composition, were used to tune the effective interactions between polymers and the substrate.…”

Section: A Surface/polymers Interactions Tuned By Surface-active DImentioning

confidence: 99%

Surface-directed phase separation in nanometer polymer films: self-stratification and pattern replication

et al. 2002

Self Cite

View full text Add to dashboard Cite

Phase separation occurs in thin films of polymer blends when molecular mobility is promoted by a temperature above the glass transition but inside the twophase region (temperature quench), or a common solvent added to the polymers (solvent quench). This phenomenon can be altered by a homogeneous surface or pre-patterned substrate, resulting, e.g., in self-stratification or pattern replication, respectively. Such self-organisation processes ordering polymer phases were observed for model polymer blends (deuterated/hydrogenated polystyrene, dPS/hPS, and deuterated/partially brominated PS, dPS/PBrS, both with hPSpolyisoprene diblocks added; dPS/poly(vinylpyridine) and PBrS/PVP) with highresolution ion beam techniques (Nuclear Reaction Analysis, profiling and mapping mode of dynamic Secondary Ion Mass Spectrometry) and Atomic Force Microscopy. The self-stratification process is strongly affected by both the range as well as the strength of the surface/polymer interactions. This is illustrated for the temperature-quenched blends with surface-active copolymer additives tuning the interactions exerted by both external surfaces. The pattern transfer from the substrate to the films is demonstrated for the solvent-quenched blends. Patterndirected composition variations (SIMS maps) coincide with free surface undulations (AFM images). The most effective pattern replication is achieved for the length scale of phase domain morphology comparable with the pattern periodicity and for carefully adjusted polymer/substrate interactions.

show abstract

Wetting in a phase separating polymer blend film: Quench depth dependence

Cited by 68 publications

References 27 publications

Interface localization-delocalization transition in a symmetric polymer blend: A finite-size scaling Monte Carlo study

Interface localization-delocalization transition in a symmetric polymer blend: A finite-size scaling Monte Carlo study

Hydrodynamic-flow-driven phase evolution in a polymer blend film modified by diblock copolymers

Surface-directed phase separation in nanometer polymer films: self-stratification and pattern replication

Contact Info

Product

Resources

About