Improved Self-Assembly of Poly(dimethylsiloxane-b-ethylene oxide) Using a Hydrogen-Bonding Additive
Improved Self-Assembly of Poly(dimethylsiloxane-b-ethylene oxide) Using a Hydrogen-Bonding Additive
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DOI：
10.1002/pola.28093
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发表时间：
2016-07-15
影响因子：
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通讯作者：
Hawker, Craig J.
中科院分区：
文献类型：
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作者：
Luo, Yingdong;Kim, Bongkeun;Hawker, Craig J.
在下一代光刻应用的定向自组装不断发展的领域中，具有增加的 Flory-Huggins 相互作用参数 (chi) 的嵌段共聚物在亚 10 nm 纳米图案的生产中发挥着重要作用。通过点击化学合成了 PDMS-b-PEO 嵌段共聚物库并确定了它们的相互作用参数 (chi)。我们的样品在 150 摄氏度时测得的最高 chi 为 0.21，这导致相分离域的周期小至 7.9 nm，表明 PDMS-b-PEO 是亚 10 nm 纳米图案化的主要候选者。为了抑制 PEO 结晶，将 PDMS-b-PEO 与 (L)-酒石酸 (LTA) 混合，从而可以调节自组装形态。此外，还观察到，随着共混物中 LTA 含量的增加，PDMS-b-PEO 的有序-无序转变温度 (T-ODT) 急剧增加，从而可以进一步控制自组装。为了理解这种现象的机制，我们提出了一种新颖的基于场的超分子模型，该模型描述了通过可逆氢键形成共聚物添加剂复合物。使用随机相位近似（RPA）计算模型的平均场相分离行为。 RPA 分析再现了与 PDMS-b-（PEO/LTA 超块）中有效 chi 的增加一致的行为。 (C) 2016 年 Wiley 期刊公司。
Block copolymers with increased Flory-Huggins interaction parameters (chi) play an essential role in the production of sub-10 nm nanopatterns in the growing field of directed self-assembly for next generation lithographic applications. A library of PDMS-b-PEO block copolymers were synthesized by click chemistry and their interaction parameters (chi) determined. The highest chi measured in our samples was 0.21 at 150 degrees C, which resulted in phase-separated domains with periods as small as 7.9 nm, suggesting that PDMS-b-PEO is a prime candidate for sub-10 nm nanopatterning. To suppress PEO crystallization, PDMS-b-PEO was blended with (L)-tartaric acid (LTA) which allows for tuning of the self-assembled morphologies. Additionally, it was observed that the order-disorder transition temperature (T-ODT) of PDMS-b-PEO increased dramatically as the amount of LTA in the blend increased, allowing for further control over self-assembly. To understand the mechanism of this phenomenon, we present a novel field-based supramolecular model, which describes the formation of copolymeradditive complexes by reversible hydrogen bonding. The mean-field phase separation behavior of the model was calculated using the random phase approximation (RPA). The RPA analysis reproduces behavior consistent with an increase of the effective chi in the PDMS-b-(PEO/ LTA suprablock). (C) 2016 Wiley Periodicals, Inc.