RAFT synthesis of block copolymers and their self-assembly properties

Farnham, William B.; Sheehan, Michael T.

doi:10.1016/b978-0-08-100250-6.00002-x

Cited by 4 publications

(3 citation statements)

References 29 publications

(25 reference statements)

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“…Thus, the most direct approach to reducing linear BCP domain spacing has been to synthesize shorter chains. High χ systems allow for shorter chains to maintain order, but the large surface energy difference between blocks introduces additional challenges for BCP synthesis and assembly. − Use of multiblock and nonlinear BCP architectures is a promising paradigm for overcoming these challenges. For example, both linear ABA triblock and ( AB ) x star copolymers form smaller ordered domains − at lower χ N ,, with narrower interfaces than their AB counterparts.…”

Section: Introductionmentioning

confidence: 99%

Impact of Cyclic Block Copolymer Chain Architecture and Degree of Polymerization on Nanoscale Domain Spacing: A Simulation and Scaling Theory Analysis

et al. 2019

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Cyclic block copolymers are predicted to assemble into nanostructured domains up to 40% smaller than their linear analogues, making them promising alternatives for nanoscale patterning applications. The limited cyclic block copolymer structures observed experimentally, however, have not met the domain reductions predicted by scaling theory. Through a systematic dissipative particle dynamics simulation study of linear and cyclic block copolymer assembly into lamellar and cylindrical nanostructures, we explore these discrepancies. We find standard implementations of scaling theory, which assume a cyclic BCP behaves as a linear molecule of half the contour length, fail to account for finite chain size effects, resulting in overpredictions of the extent of domain shrinkage upon cyclization. We propose a revised scaling law that clarifies the interplay of chain length, segregation strength, and chain architecture in determining domain spacing reduction attainable by molecular cyclization and offers an explanation for the discrepancies between prior theoretical predictions and experimental results.

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Section: Introductionmentioning

confidence: 99%

Impact of Cyclic Block Copolymer Chain Architecture and Degree of Polymerization on Nanoscale Domain Spacing: A Simulation and Scaling Theory Analysis

et al. 2019

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“…Alternatively, the gyroid phase is bicontinuous (i.e., both domains create networks) and hence does not require any alignment, but is only stable in a very narrow region of the phase diagram 24 . Copolymers with designed monomer sequences can access a broader set of conditions where these bicontinuous microphases can be accessed, but the careful control of polymer synthesis conditions can add to manufacturing costs 25,26 .…”

Section: Copolymer Microphase Separation and Formation Of Nanostructuresmentioning

confidence: 99%

Responsive filtration membranes by polymer self-assembly

et al. 2016

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Membrane technologies are essential for water treatment, bioprocessing and chemical manufacturing. Stimuli-responsive membranes respond to changes in feed conditions (e.g., temperature, pH) or external stimuli (e.g., magnetic field, light) with a change in performance parameters (permeability, selectivity). This enables new functionalities such as tunable performance, self-cleaning and smart-valve behavior. Polymer self-assembly is a crucial tool for manufacturing such membranes using scalable methods, enabling easier commercialization. This review surveys approaches to impart stimuli responsive behavior to membrane filters using polymer self-assembly.

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“…Meanwhile, feature size depends most strongly on N , which controls the overall polymer size, and weakly on χ, which characterizes the repulsion between the chemically distinct blocks. High χ systems allow for shorter chains (smaller N and therefore smaller feature sizes) to maintain order, but the large surface energy difference between blocks introduces additional challenges for BCP synthesis and assembly. − BCP architecture provides an additional way to optimize nanofeature size.…”

Section: Introductionmentioning

confidence: 99%

Blending Linear and Cyclic Block Copolymers to Manipulate Nanolithographic Feature Dimensions

Goodson

Rick

Troxler

et al. 2021

ACS Appl. Polym. Mater.

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Block copolymers (BCPs) consist of two or more covalently bound chemically distinct homopolymer blocks. These macromolecules have emerging applications in photonics, membrane separations, and nanolithography stemming from their self-assembly into regular nanoscale structures. Theory suggests that cyclic BCPs should form features up to 40% smaller than their linear analogs while also exhibiting superior thin-film stability and assembly dynamics. However, the complex syntheses required to produce cyclic polymers mean that a need for pure cyclic BCPs would present a challenge to large-scale manufacturing. Here, we employ dissipative particle dynamics simulations to probe the self-assembly behavior of cyclic/linear BCP blends, focusing on nanofeature size and interfacial width as these qualities are critical to nanopatterning applications. We find that for mixtures of symmetric cyclic and linear polymers with equivalent lengths, up to 10% synthetic impurity has a minimal impact on cyclic BCP feature dimensions and interfacial roughness. On the other hand, blending with cyclic BCPs provides a route to “fine-tune” linear BCP feature sizes. We analyze simulated blend domain spacings within the context of strong segregation theory and find significant deviations between simulation and theory that arise from molecular-level packing motifs not included in theory. These insights into blend self-assembly will assist experimentalists in rationally designing BCP materials for advanced nanolithography applications.

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RAFT synthesis of block copolymers and their self-assembly properties

Cited by 4 publications

References 29 publications

Impact of Cyclic Block Copolymer Chain Architecture and Degree of Polymerization on Nanoscale Domain Spacing: A Simulation and Scaling Theory Analysis

Impact of Cyclic Block Copolymer Chain Architecture and Degree of Polymerization on Nanoscale Domain Spacing: A Simulation and Scaling Theory Analysis

Responsive filtration membranes by polymer self-assembly

Blending Linear and Cyclic Block Copolymers to Manipulate Nanolithographic Feature Dimensions

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