Energy Transfer Studies of Binary Block Copolymer Blends. 1. Effect of Composition on the Interface Area per Chain and the Lamellar Size

Tcherkasskaya, Olga; Ni, Shaoru; Winnik, Mitchell A.

doi:10.1021/ma9612891

Cited by 8 publications

(8 citation statements)

References 39 publications

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“…Furthermore, the anthracenyl group is less prone to form excimers than other aromatic fluorophores such as pyrenyl groups,10 which may disturb the quantification of the GPC signal at a fixed emission wavelength. The anthracenyl group has been used by several researchers to prepare fluorescent‐labeled homopolymers or block copolymers8, 11 for various polymer physics studies 12–14.…”

Section: Resultsmentioning

confidence: 99%

Anionic synthesis and detection of fluorescence-labeled polymers with a terminal anhydride group

Moon

Hoye

Macosko

2000

J. Polym. Sci. A Polym. Chem.

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To monitor polymer–polymer coupling reactions between two different monofunctional polymers in dilute polymer blends, fluorescence‐labeled anhydride‐functional polystyrene (PS) and poly(methyl methacrylate) (PMMA) were prepared by conventional anionic polymerization. Sequential trapping of lithiopolystyrene by 1‐(2‐anthryl)‐1‐phenylethylene (APE) and then di‐t‐butyl maleate (4) provided, after pyrolysis, anhydride‐functional fluorescent PS. Fluorescent PMMA anhydride (8) was synthesized with sec‐butyllithium/APE as an initiator for the anionic polymerization of methyl methacrylate, trapping by 4, and pyrolysis. These polymers could be reacted with amine‐functional polymers by melt blending, and the reaction progress could be monitored by gel permeation chromatography coupled with fluorescence detection. This technique not only allows monitoring of the coupling reaction with high sensitivity (ca. 100 times more sensitive than refractive index detection) but also permits selective detection because unlabeled polymers are invisible to fluorescence detection. This highly sensitive and selective detection methodology was also used to monitor the coupling reaction of 8 with PS‐NH2 at a thin‐film interface, which was otherwise difficult to detect by conventional methods. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2177–2185, 2000

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Section: Resultsmentioning

confidence: 99%

Anionic synthesis and detection of fluorescence-labeled polymers with a terminal anhydride group

Moon

Hoye

Macosko

2000

J. Polym. Sci. A Polym. Chem.

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“…Binary blends of block copolymers offer a unique opportunity to produce a new class of polymeric materials in that one has a great deal of flexibility in the choice of constituent components. 1 In the past, a large number of experimental [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] and theoretical [22][23][24][25][26][27][28][29] investigations were reported on various issues (e.g., morphology, phase separation, phase transition) associated with the binary blends of diblock copolymers. With a few exceptions, [2][3][4] most of the experimental [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]…”

Section: Introductionmentioning

confidence: 99%

“…1 In the past, a large number of experimental [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] and theoretical [22][23][24][25][26][27][28][29] investigations were reported on various issues (e.g., morphology, phase separation, phase transition) associated with the binary blends of diblock copolymers. With a few exceptions, [2][3][4] most of the experimental [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] and theoretical studies [22][23]…”

Section: Introductionmentioning

confidence: 99%

Temperature−Composition Phase Diagrams for Binary Blends Consisting of Chemically Dissimilar Diblock Copolymers

Vaidya

Han

2000

Macromolecules

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Temperature-composition phase diagrams for binary blends of chemically dissimilar diblock copolymers, (A-block-B) and (A-block-C) copolymers, were constructed experimentally. For the study, two polystyrene-block-polyisoprene (SI diblock) copolymers (SI-7/8 and SI-10/53) and three polystyrene-blockpolybutadiene (SB diblock) copolymers (SB-9/8, SB-5/36, and SB-10/10) were used. Three binary blend systems were prepared: (i) (SI-7/8)/(SB-9/8) blends consisting of two nearly symmetric lamella-forming diblock copolymers having different chemical structures, (ii) (SI-10/53)/(SB-5/36) blends consisting of two highly asymmetric sphere-forming diblock copolymers having different chemical structures, and (iii) (SB-10/10)/(SB-9/8) blends consisting of two nearly symmetric lamella-forming diblock copolymers having different microstructures in the polybutene block. It has been found, via transmission electron microscopy (TEM), that no macrophase separation took place in each binary blend system over the entire range of blend compositions investigated. The order-disorder transition temperature of each binary blend was determined using oscillatory shear rheometry, enabling us to construct a temperature-composition phase diagram for each blend system. It has been found that the temperature-composition phase diagrams for the (SB-9/8)/(SI-7/8) and (SB-10/10)/(SB-9/8) blend systems follow nearly a linear relationship, whereas the temperature-composition phase diagrams for the (SI-10/53)/(SB-5/36) blend system show positive deviation from linearity. The experimentally determined temperature-composition phase diagrams are found to be consistent with the predictions from random phase approximation calculations. It has been found that the microdomain structure, as determined by TEM, of each binary blend was the same as that of the constituent block copolymers.

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“…In regards to the potential stability problem in the physical blending system, chemical methods was alternatively considered in which the organic fluorophores were chemically linked to polymer chains to exert the same isolation effect. Previously, there are several reports8–15 relating to these fluorophore‐centered polymers. For example, dihydropyrrolpyrrolidone fluorophore was build as the center of a dendrimer and investigated by confocal microscope to distinguish the emission of single molecule from the aggregated cluster 8.…”

Section: Introductionmentioning

confidence: 99%

“…Pyrene was also incorporated as the pendant group to prepare a system of “hydrophobically modified alkali swellable emulsion polymer (HASE).” By selecting tetrahydrofuran or water as the dispersive medium, emission from the isolated or the aggregated pyrene can be both detected 9. In distinct to above dendrimeric or side‐chain system, fluorophores were also incorporated as center of linear polymers such as polystyrene‐10, 11 and polyisoprene–poly(methyl methacrylate)12 diblock copolymers; and the ratios of the microdomain size to thickness of boundary‐domain interphase can be formulated from their corresponding emission spectra. In addition, elastomeric polystyrene–polyisoprene–polystyrene triblock copolymer with central mono‐ or di‐carbazole fluorophore13 had been successfully prepared by anionic polymerization.…”

Section: Introductionmentioning

confidence: 99%

Restraining the associations of anthracene fluorophore by chemically linking to poly(methyl methacrylate)

Su¹,

Hong²,

Lin³

2007

J of Applied Polymer Sci

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Associations (dimer or aggregate) of anthracene (An) fluorophores tend to interrupt the monomer emission and reduce the quantum yield (F PL ); therefore, poly(methyl methacrylate) (PMMA) chain was used in this study to chemically link to anthracene and to block the mutual associations among the anthracene fluorophores. With this aim, the target polymers were prepared by anionic polymerizations with 9,10-dibromoanthracene/s-butyllithium as initiating system to proceed polymerizations of methyl methacrylate (MMA) directly or in the presence of 1,1-diphenylethylene (DPE). Use of DPE before addition of MMA produces stable initiating anionic species and avoids potential side reactions during polymerization; however, it also introduces four b-phenylene rings around the central anthracene ring, which interfere with the corresponding emission pattern and reduce the F PL (32%) value due to potential interactions between phenylene rings and anthracene. On the contrast, polymerization without participation of DPE results in polymer with central anthracene ring directly connected to two PMMA chains, which gives clean vibronic emission pattern with limited association emissions and enhanced F PL (52%) value. Physical blending of anthracene by PMMA is less efficient to restrain the associations and results in a film of lower F PL (20%).

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Energy Transfer Studies of Binary Block Copolymer Blends. 1. Effect of Composition on the Interface Area per Chain and the Lamellar Size

Cited by 8 publications

References 39 publications

Anionic synthesis and detection of fluorescence-labeled polymers with a terminal anhydride group

Anionic synthesis and detection of fluorescence-labeled polymers with a terminal anhydride group

Temperature−Composition Phase Diagrams for Binary Blends Consisting of Chemically Dissimilar Diblock Copolymers

Restraining the associations of anthracene fluorophore by chemically linking to poly(methyl methacrylate)

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