Chain conformation of a block polymer in a microphase-separated structure

Matsushita, Yushu; Mori, Katsuaki; Mogi, Yasuhiro; Saguchi, Ryuichi; Noda, Ichiro; Nagasawa, Mitsuru; Chang, Taihyun; Glinka, C. J.; Han, Charles C.

doi:10.1021/ma00221a020

Cited by 72 publications

(82 citation statements)

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“…SP samples except SP29 were prepared and characterized in previous works. [16][17][18][19][20][21][22] and DP samples were prepared in this work in the same manner as in the previous work. 16 • 17 The molecular weight of DP20 was measured by light scattering in the same manner as in the previous work.…”

Section: Methodsmentioning

confidence: 99%

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Order-Disorder Transition of Symmetric Poly(styrene-b-2-vinylpyridine) in Bulk and Solution

Takahashi

Kitade

Noda

et al. 1998

Polym J

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ABSTRACT:Order-disorder transitions (ODT) of symmetric poly(styrene-b-2-vinylpyridine) in a common good solvent and bulk were determined by dynamic rheological and small-angle neutron scattering measurements. ODT conditions determined by both methods are consistent with each other and the degree of polymerization dependence of critical volume fraction in solution at almost constant temperature agrees with the theoretical prediction for semidilute solutions. However, semidilute behavior persists to a much higher concentration than for ordinary polymer solutions and the crossover from semidilute to concentrated regimes is not clear. KEY WORDSOrder-Disorder Transition / Symmetric Diblock Copolymers / Poly(styrene-b-2-vinylpyridine) / Small-Angle Neutron Scattering/ Semidilute Region/ Block copolymers exhibit a phase transition between ordered (microphase-separated) and disordered (homogeneous) states under certain conditions. The orderdisorder transitions (ODT) of block copolymers have been extensively studied and the results are summarized in the literature. 1 -8 A brief outline of the results is as follows.Theoretically, the phase diagram for diblock copolymers in bulk was first discussed by the mean-field approach,9 and later modified to include fluctuation effects. 10 According to the theory, the ODT of symmetric diblock copolymers occurs at (xN)ooT= 10.5 +41.0. N-113 ( 1) where x is the Flory-Huggins interaction parameter, N is the number of statistical segments (monomers) per copolymer molecule and (2) is a term for fluctuation correction. Here (S 2 ), Mm p, and NA are the mean square radius of gyration, number-average molecular weight, mass density and Avogadro's number, respectively. It was also predicted that eq 1 and 2 can be applied to block copolymer solutions by appropriate replacement of the parameters. 11 • 12 Experimentally, most studies on ODT have been carried out for polystyrene-polydiene diblock copolymers such as poly(styrene-b-isoprene) (SI) and hydrocarbon diblock copolymers such as poly(ethylenepropylene-b-ethylethylene) in bulk. Several experimental methods to determine ODT have been examined. At present, small-angle X-ray scattering, small-angle neutron scattering (SANS), birefringence measurement and dynamic rheological measurements (DRM) are generally used. 1 -s Recently, we studied the viscoelastic properties of SI diblock copolymer solutions near ODT and reported that t To whom correspondence should be addressed. 388the shear rate dependence of the first normal stress difference changes from first order to second order, after shear-induced alignment of the microdomain structure occurs. 13 Generally speaking, systematic studies on viscoelastic properties, especially those under steady shear flow are much easier in solution than in bulk. Difference in viscoelastic properties of block components may affect the shear-induced alignment. For better understanding of the viscoelastic properties and shearinduced alignment of diblock copolymers near ODT, it is essential to study them both ...

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Section: Methodsmentioning

confidence: 99%

“…15 Matsushita et al,[16][17][18][19][20][21][22] studied the preparation, characterization, morphology and chain conformation for poly(styrene-b-2-vinylpyridine) (SP) and the deuterated analogue, i.e., poly(styrene-d 8 -b-2-vinylpyridine) (DP) with different compositions, molecular weights, and narrow molecular weight distributions.…”

mentioning

confidence: 99%

Order-Disorder Transition of Symmetric Poly(styrene-b-2-vinylpyridine) in Bulk and Solution

Takahashi

Kitade

Noda

et al. 1998

Polym J

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“…Early experiments yielded values for the breadth of the interface higher than predicted from theoretical description of composition profiles, [4,5] and also found chain extensions in the direction perpendicular to the interface [1][2][3] that at the time had not yet been considered theoretically. Computer simulations of the microphase separated copolymer states offer the possibility to obtain even more details about the interfacial structures.…”

Section: Introductionmentioning

confidence: 97%

“…neutron scattering [1][2][3] and reflectivity [4,5] measurements. Early experiments yielded values for the breadth of the interface higher than predicted from theoretical description of composition profiles, [4,5] and also found chain extensions in the direction perpendicular to the interface [1][2][3] that at the time had not yet been considered theoretically.…”

Section: Introductionmentioning

confidence: 99%

Interface Orientation and Chain Conformation in Simulated Symmetric Diblock Copolymer Lamellar Systems

Yang

Winnik

Pakuła

2005

Macro Theory & Simulations

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Summary: We describe the results of Monte Carlo simulations, based on the cooperative motion algorithm, of the lamellar structure generated at finite temperature by a symmetric diblock copolymer. The (70 × 70 × 70) simulation box in which the polymer chains were embedded for each simulation was rotated, based on the interface orientation, to bring the interfacial planes of the simulated structure into parallel. We found that the interface thickness, as defined by the distribution of the junction points, became narrower at lower temperature, and that the interface plane was characterized by a waviness with a maximum peak‐to‐valley distance of 20–30 lattice bonds. Compared with the isotropic state (T/N = ∞), chains at lower temperatures were stretched in the direction perpendicular to the interface; but only modestly compressed in the direction parallel to the interface. Individual block chains within the lamellar domains still behave like random coils. The block copolymer molecules exhibit only a modest tendency to orient themselves with their end‐to‐end vector perpendicular to the plane of the lamellar interface. Considered as an ensemble average, the results we obtained are similar to those reported from small angle neutron scattering measurements for the mean conformation of the PSd blocks of symmetrical PSd‐PVP diblock copolymers.2‐D projections onto the X‐Z plane of the end beads for the A‐ and B‐chains (gray) and the junction points J (black) at T/N = 0.2. The interface plane is oriented parallel to the Y‐Z plane by rotating the simulation box. The distribution profiles of junction points and the end beads across the system in the direction of interface normal are shown in the lower part of the figure.image2‐D projections onto the X‐Z plane of the end beads for the A‐ and B‐chains (gray) and the junction points J (black) at T/N = 0.2. The interface plane is oriented parallel to the Y‐Z plane by rotating the simulation box. The distribution profiles of junction points and the end beads across the system in the direction of interface normal are shown in the lower part of the figure.

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“…Moreover, nanophase-separated structures were explored at the molecular level using neutron scattering methods by introducing deuterium labeling technique in this period. 16,17 The next generation occurred during the late 1980s and 1990s when complex morphologies with periodic surfaces were identified, some of which included bicontinuous structures for two-component linear 18 and star-branched 19 copolymers, as well as tricontinuous structures for three-component linear terpolymers. 20 The peculiar morphology for an amphiphilic diblock copolymer-aluminosilicate nanocomposite was also reported.…”

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Precise Molecular Design of Complex Polymers and Morphology Control of Their Hierarchical Multiphase Structures

Matsushita

2008

Polym J

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This report reviews the recent advances in morphological studies on block copolymer and related multiple component polymer systems that possess characteristic chain connectivity and non-covalent bonding interactions, which were mostly done in our research group. Among many topics, three types of multi-phase systems are picked up and examined in this article. The first system consists of multiblock terpolymers. Hierarchical structures having double periodicity have been formulated for sample polymers including block chains with different lengths. The second one is represented by star-shaped terpolymers of the ABC type, which easily form three-phase cylinder-like structure whose cross sections exhibit periodic tiling structures. They show several Archimedean tilings and one of them forms quasicrystalline tiling with dodecagonal symmetry. The third one is composed of block copolymer/block copolymer blends or a block copolymer/homopolymer blend with hydrogen bonding interactions. It has been found these blends represent very striking phase structures including new mesoscopic tiling structures. These structures with new self-assembly manners due to strategic molecular design open the door to production of many highly functional materials.KEY WORDS: Block Polymer / Morphology / Hierarchical Structure / Archimedean Tiling / Quasicrystalline Tiling / Studies on self-assembling structures of block copolymers have started in the 1960s, when the first reports on the discovery of highly periodic structures for block copolymers in bulk and in concentrated solutions were published.1,2 Successively, these structures were verified by measurements of viscoelastic and thermal properties 3,4 and finally observed by morphological studies with electron microscopy. 5,6 The basic concept of morphological transition with composition was proposed during this period, 7 since then the concept has been the basis of any morphological studies in block copolymerbased complex systems. Subsequently, started from the 1970s through the early 1990s, morphological features were extensively studied both by theoretical 8-10 and experimental works.11-13 During this period, physical aspects of several properties such as phase transition and phase stability were fully focused, where the order-order phase transition 9,14 or order-disorder transition 9,15 was investigated by varying the magnitudes of the external field such as shear flow and/or temperature. Moreover, nanophase-separated structures were explored at the molecular level using neutron scattering methods by introducing deuterium labeling technique in this period. 16,17 The next generation occurred during the late 1980s and 1990s when complex morphologies with periodic surfaces were identified, some of which included bicontinuous structures for two-component linear 18 and star-branched 19 copolymers, as well as tricontinuous structures for three-component linear terpolymers. 20 The peculiar morphology for an amphiphilic diblock copolymer-aluminosilicate nanocomposite was also reported. 21 Among...

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Chain conformation of a block polymer in a microphase-separated structure

Cited by 72 publications

References 5 publications

Order-Disorder Transition of Symmetric Poly(styrene-b-2-vinylpyridine) in Bulk and Solution

Order-Disorder Transition of Symmetric Poly(styrene-b-2-vinylpyridine) in Bulk and Solution

Interface Orientation and Chain Conformation in Simulated Symmetric Diblock Copolymer Lamellar Systems

Precise Molecular Design of Complex Polymers and Morphology Control of Their Hierarchical Multiphase Structures

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