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
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DOI：
10.1021/acs.macromol.9b02015
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发表时间：
2019-12-10
期刊：
影响因子：
5.5
通讯作者：
Albert, Julie N. L.
中科院分区：
文献类型：
--
作者：
Goodson, Amy D.;Troxler, Jessie E.;Albert, Julie N. L.
预计环状嵌段共聚物组装成纳米结构域比其线性类似物小高达40%，使其成为纳米级图案化应用的有前途的替代品。然而，实验观察到的有限的环状嵌段共聚物结构，并没有满足标度理论预测的域减少。通过系统的耗散粒子动力学模拟研究线性和环状嵌段共聚物组装成层状和圆柱形纳米结构，我们探索这些差异。我们发现标度理论的标准实现，它假设一个环状BCP的行为作为一个线性分子的轮廓长度的一半，未能考虑有限的链尺寸效应，导致过度预测的程度域收缩后环化。我们提出了一个修订的标度律，阐明了链长、分离强度和链结构在确定分子环化可实现的域间距减少方面的相互作用，并为之前的理论预测和实验结果之间的差异提供了解释。
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.