Aggregation behaviors of AB-type brush-block-brush amphiphilic copolymers in aqueous media

Ishizu, Koji; Satoh, Junichiro; Toyoda, Keiichi; Sogabe, Atsushi

doi:10.1023/b:jmsc.0000033411.75529.34

Cited by 15 publications

(20 citation statements)

References 20 publications

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“…Based on the strategies described above, cylindrical polymer brushes with various architectures have been prepared. Core-shell cylindrical brushes, [18][19][20][21][22] brushes with a grafting density gradient, [23,24] hetero-grafted brushes, [25][26][27] brush block copolymers, [28] star brushes, [29,30] ring brushes, [31] and double-grafted brushes [32] have been prepared. Cylindrical brushes with different functionalities were also available.…”

Section: Full Papermentioning

confidence: 99%

Double‐Grafted Cylindrical Brushes: Synthesis and Characterization of Poly(lauryl methacrylate) Brushes

Becker

Yuan

et al. 2007

Macro Chemistry & Physics

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Double‐grafted cylindrical brushes with poly(lauryl methacrylate) (PLMA) as the side chains were synthesized using the grafting‐from strategy via atom transfer radical polymerization (ATRP). The polyinitiator poly[2‐(2‐bromoisobutyryloxy)ethyl methacrylate] (PBIEM) with $\overline {DP} _{\rm n}$ = 240 and 1 500 served as the backbone. The PLMA side chains of the brushes carry long alkyl chains. GPC and 1H NMR measurements confirmed the successful formation of the PLMA cylindrical brushes. The side chains were cleaved from the cylindrical brushes by transesterification. GPC and 1H NMR results indicate that the initiating efficiency of the bromoester groups on the backbone for the bulky monomer was in the range of 0.34 ≤ f ≤ 0.67. Static and dynamic light scattering show that the ratio of the radius of gyration to the hydrodynamic radius, Rg/Rh, is in the range of 1.2–1.3, indicating that the LMA cylindrical brushes are semiflexible in solution. Atomic force microscopy (AFM) measurements show that short PLMA brushes exhibit a spherical morphology while the long brushes exhibit a worm‐like structure. DSC displayed melting peaks at around −30 °C, indicating the alkyl side chains of the PLMA chains in the double‐grafted cylindrical brushes are crystallizable.magnified image

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Section: Full Papermentioning

confidence: 99%

Double‐Grafted Cylindrical Brushes: Synthesis and Characterization of Poly(lauryl methacrylate) Brushes

Becker

Yuan

et al. 2007

Macro Chemistry & Physics

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“…41 Figure 19a shows the hydrodynamic diameter (D h ) distribution of P23 in an aqueous solution (2 Â 10 À2 mg mL À1 ) by DLS measurement. Polymer solution showed turbidity but no precipitates were observed.…”

Section: Block-type Copolymer Brushesmentioning

confidence: 99%

Architecture of Multi-Component Copolymer Brushes: Synthesis, Solution Properties and Application for Nanodevices

Ishizu

2004

Polym J

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ABSTRACT:In this review article, we describe the architecture of multi-component copolymer brushes. These copolymer brushes can be classified into tree types, i.e., double-cylinder-type, prototype, and block-type. Double-cylinder-type copolymer brushes were prepared by free-radical polymerization of corresponding diblock macromonomer or by the ''grafting from'' approach using atom transfer radical polymerization (ATRP). Alternating free-radical copolymerization of the mixture of two macromonomers provided prototype copolymer brushes. ATRP was applied to the synthesis of AB-type brush-block-brush (block-type) copolymers. All copolymer brushes were molecularly dissolved in a dilute solution due to densely branched side chains and took geometrically anisotropic conformation such as cylinder with increasing aspect ratio. In self-assembly process of amphiphilic prototype copolymer brushes in water, hierarchical generations from small rods to large rods were observed, because copolymer brushes exhibited phase-separated hydrophobic/hydrophilic domains. Moreover, binding of anionic/nonionic polyeletrolyte prototype brushes with cationic linear polyelectrolyte formed an interesting complex of a high order by electrostatic interaction. On the other hand, the molecular wires in electronic nanodevices were prepared by forming conducting polypyrroles with an internal core of double-cylider-type copolymer brushes as templates, where as the outer cylinder parts play the role of an insulator. [DOI 10.1295/polymj.36.775] KEY WORDS Multi-component Copolymer Brush / Double-cylinder-type / Prototype / Blocktype / Macromonomer / ATRP / Aternating Copolymerization / Molecular Wire / Binding / Nanostructured polymers are of rapidly growing interest because of their sized-coupled properties. Generally, the branched polymer has a smaller hydrodynamic dimension than a linear polymer with the same molecular weight. The interest in branched polymers arises from their compactness and their enhanced segment density. Recently, a new class of branched architectural polymers, such as nanocylinders, is attracting attention with expectation that their unique structures may result in unusual properties. It is well known that comb polymers with densely grafted side chains in a good solvent can adopt a worm-like cylinder brush conformations, in which the side chains are stretched in the direction normal to the backbone, owing to the excluded-volume interaction. The polymerization of macromonomers provides regular multi-branched polymers with dense branching. Since both the degree of polymerization (DP n ) and the length of branches are varied, poly(macromonomer)s, often so-called ''polymer brushes'', are interesting models for the study of branched polymers.1-9 More recently, we have systematically investigated the architecture of multi-component copolymer brushes. Figure 1 shows the illustration of three types of multi-component copolymer brushes. Various strategies can be designed to construct such structures. For example, one strategies for the...

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“…[60] An altogether different strategy to create Janus particles uses amphiphilic block copolymer brushes. [16,[61][62][63] Such macromolecular architectures self-assemble in block-selective solvents and typically form unimolecular rodlike nanoobjects in which the individual polymer grafts form separated domains. …”

Section: Janus Particlesmentioning

confidence: 99%

Polymeric Janus Particles

Wurm¹,

Kilbinger²

2009

Angew Chem Int Ed

221

150

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Since de Gennes' Nobel lecture in 1991, in which he coined the term "Janus grains", research into asymmetric particles has boomed. Macroscopic, microscopic and nanoscopic particles have been prepared in which certain parts of their surface differ in chemical composition, polarity, color, or any other property. Spherical, cylindrical, disc-like, snowman-, hamburger-, and raspberry-like structures have been synthesized from organic or inorganic materials or even as hybrids of both. Synthetic strategies towards such particles vary greatly from simple polymer mixtures to the bulk self-assembly of sophisticated terpolymers to immobilization methods of symmetric particles. Polymeric Janus particles are particularly promising, as they can often be prepared cheaply and sometimes even on larger scales.

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Aggregation behaviors of AB-type brush-block-brush amphiphilic copolymers in aqueous media

Cited by 15 publications

References 20 publications

Double‐Grafted Cylindrical Brushes: Synthesis and Characterization of Poly(lauryl methacrylate) Brushes

Double‐Grafted Cylindrical Brushes: Synthesis and Characterization of Poly(lauryl methacrylate) Brushes

Architecture of Multi-Component Copolymer Brushes: Synthesis, Solution Properties and Application for Nanodevices

Polymeric Janus Particles

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