The phase diagram of the system poly(styrene- block - n -butyl methacrylate)

Fischer, H.; Weidisch, Roland; Stamm, Manfred; Budde, H.; Höring, S.

doi:10.1007/s003960000363

Cited by 21 publications

(26 citation statements)

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“…All the block copolymers employed in the literature 1-26 to investigate the phase behavior of binary mixtures exhibit the order-to-disordered transition (ODT); thus, a homogeneous state of the mixture could be obtained upon heating. However, some block copolymers exhibit lower disorder-to-order transition (LDOT) upon heating. − The driving force for the LDOT is of entropic origin, thus driven either by disparity in compressibility or by directional interactions, which is quite different from that for the ODT. However, to the best of our knowledge, the phase diagram of a binary mixture of a block copolymer with LDOT and a homopolymer has not been studied experimentally or theoretically.…”

Section: Introductionmentioning

confidence: 99%

Phase Behavior of a Binary Mixture of a Block Copolymer with Lower Disorder-to-Order Transition and a Homopolymer

et al. 2006

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The phase diagrams for a binary mixture of symmetric polystyrene-block-poly(n-butyl methacrylate) copolymer (PS-b-PnBMA) exhibiting lower disorder-to-order transition (LDOT) and PS homopolymer and a binary mixture of PS-b-PnBMA and PnBMA homopolymer were investigated by using polarizing optical microscopy, turbidity measurement, small-angle X-ray scattering, rheology, and transmission electron microscopy. Emphasis was placed on the effect of the molecular weight of homopolymers on the phase behavior of the mixtures. We found that when the molecular weight of a homopolymer was smaller than the half of molecular weight of the corresponding block, LDOT of the mixture increased (thus miscibility was enhanced). However, the changes of microdomains for the mixtures containing PS homopolymer are different from those for the mixtures containing PnBMA homopolymer, especially when the molecular weight of homopolymer becomes large. For instance, for the mixture of PS-b-PnBMA and PnBMA with a molecular weight of 65000, lamellar microdomains structure was destroyed even at the addition of 20 wt % of PnBMA homopolymer. On the other hand, for the mixture of PS-b-PnBMA and PS with a molecular weight 68000, the lamellar microdomain structure was maintained up to 40% of PS homopolymer. The phase diagrams of the mixtures were compared with predictions developed based on the compressible random phase approximation.

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Section: Introductionmentioning

confidence: 99%

Phase Behavior of a Binary Mixture of a Block Copolymer with Lower Disorder-to-Order Transition and a Homopolymer

et al. 2006

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“…Block copolymers self-assemble into various microphase-separated morphologies, and the ordered morphology in nanoscale has attracted much attention due to its potential applications of nanostructured materials or nanotemplates. − The phase behavior of diblock copolymers in bulk was found to be predictable in terms of the total number of the segment ( N ), composition ( f ), and the interaction parameter (χ) of two blocks, and the phase diagrams of diblock copolymers are often constructed in the form of N χ vs f plot. − Since the χ parameter is a function of temperature, such phase diagrams has been experimentally constructed from the temperature dependent phase behaviors of block copolymers. − …”

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confidence: 99%

Effect of Film Thickness on the Phase Behaviors of Diblock Copolymer Thin Film

et al. 2010

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A phase diagram was constructed for a polystyrene-block-polyisoprene (PS-b-PI, M(W) = 32 700, f(PI) = 0.670) in thin films on Si wafer as a function of film thickness over the range of 150-2410 nm (7-107L(0) (L(0): domain spacing)). The PS-b-PI exhibits a variety of ordered phases from hexagonally perforated lamellar (HPL) via double gyroid (DG) to hexagonally packed cylinder (HEX) before going to the disordered (DIS) phase upon heating. The morphology of the PS-b-PI in thin film was investigated by grazing incidence small-angle X-ray scattering, transmission electron microscopy, and transmission electron microtomography. In thin film, the phase transition temperature is difficult to be determined unequivocally with in situ heating processes since the phase transition is slow and two phases coexist over a wide temperature range. Therefore, in an effort to find an "equilibrium" phase, we determined the long-term stable phase formed after cooling the film from the DIS phase to a target temperature and annealing for 24 h at the temperature. The temperature windows of stable ordered phases are strongly influenced by the film thickness. As the film thickness decreases, the temperature window of layer-like structures such as HPL and HEX becomes wider, whereas that of the DG stable region decreases. For the films thinner than 160 nm (8L(0)), only the HPL phase was found. In the films exhibiting DG phase, a perforated layer structure at the free surface was found, which gradually converts to the internal DG structure. The relief of interfacial tension by preferential wetting appears to play an important role in controlling the morphology in very thin films.

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“…In the absence of substrates and the nanoparticles, one would expect to obtain bulk physical properties of the block copolymers that agree with reported literature values. Bulk PS–PBMA is a well-studied system, − and various groups have reported a wide range of values for the χ AB interaction parameter as well as the Kuhn segment lengths. Spiro et al summarized reported literature values of these parameters as well as presented their own conformationally asymmetric SCFT model for the PS–PBMA diblock copolymer.…”

Section: Resultsmentioning

confidence: 99%

Interpreting Neutron Reflectivity Profiles of Diblock Copolymer Nanocomposite Thin Films Using Hybrid Particle-Field Simulations

Mahalik¹,

Dugger²,

Sides

et al. 2018

Macromolecules

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Mixtures of block copolymers and nanoparticles (block copolymer nanocomposites) are known to microphase separate into a plethora of microstructures, depending on the composition, length scale, and nature of interactions among its different constituents. Confining these nanocomposites in thin films yields an even larger array of structures, which are not normally observed in the bulk. In contrast to the bulk, exploring various microstructures in thin films by the experimental route remains a challenging task. In this work, we present a modeling scheme using the hybrid particle-field simulation approach based on a coarse-grained model for representing polymer chains by continuous curves and coupling fictitious dynamics of nanoparticles to the thermodynamic forces. The simulation approach is general enough to predict microphase separation in thin films of any block copolymer nanocomposite with the specific details encoded in the interaction parameters. The approach is benchmarked by comparisons with the depth profiles obtained from the neutron reflectivity experiments for symmetric poly(deuterated styrene-b-n-butyl methacrylate) copolymers blended with spherical magnetite nanoparticles covered by hydrogenated poly(styrene) corona. We show that the hybrid particle-field approach is an accurate way to model and extract quantitative information about the physical parameters in the block copolymer nanocomposites. This work benchmarks the application of the hybrid particle-field model to derive the interaction parameters for exploring different microstructures in thin films containing block copolymer nanocomposites.

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The phase diagram of the system poly(styrene- block - n -butyl methacrylate)

Cited by 21 publications

References 0 publications

Phase Behavior of a Binary Mixture of a Block Copolymer with Lower Disorder-to-Order Transition and a Homopolymer

Phase Behavior of a Binary Mixture of a Block Copolymer with Lower Disorder-to-Order Transition and a Homopolymer

Effect of Film Thickness on the Phase Behaviors of Diblock Copolymer Thin Film

Interpreting Neutron Reflectivity Profiles of Diblock Copolymer Nanocomposite Thin Films Using Hybrid Particle-Field Simulations

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