Entropic death of nonpatterned and nanopatterned polyelectrolyte brushes
Entropic death of nonpatterned and nanopatterned polyelectrolyte brushes
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DOI：
10.1002/pola.29384
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发表时间：
2019-06-15
影响因子：
--
通讯作者：
Ruehe, Juergen
中科院分区：
文献类型：
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作者：
Menzel, Matthias;Chen, Wei-Liang;Ruehe, Juergen
研究了无图案和纳米图案强聚电解质刷（PEB）的稳定性与刷特性和接触液体特性的函数关系。聚(4-甲基乙烯基碘化吡啶) (PMeVP) 的高分子量 PEB 采用表面引发的自由基链聚合合成。图案尺寸范围为 50 至 200 nm 的纳米图案刷 (NPB) 线是通过使用深紫外光刻对引发层进行图案化，然后从图案层开始进行刷生长来生成的。将具有不同充电程度和接枝密度的均质PEB暴露于不同温度的水和盐溶液中不同的时间。通过干态椭圆光度法和原子力显微镜测量来监测降解情况。可以观察到与“熵弹簧”模型一致的更强烈膨胀的聚合物刷的增强去接枝。根据无图案刷的结果，NPB 暴露在不同温度和外部盐含量的水中不同时间。与直觉相反，NPB 显示出较小图案的脱接增加，这是由于纳米刷和微刷的聚合物链动力学不同。我们研究了热力学和动力学参数对（纳米图案）PEB 稳定性的影响，并讨论了此类薄膜中缠结和复合物形成的作用。 (c) 2019 年 Wiley periodicals, Inc. J. Polym。科学，A 部分：聚合物。化学。 2019, 57, 1283-1295
The stability of nonpatterned and nanopatterned strong polyelectrolyte brushes (PEBs) is studied as a function of both brush character and the properties of a contacting liquid. High-molecular-weight PEBs of poly(4-methyl vinylpyridinium iodide) (PMeVP) are synthesized using surface-initiated radical-chain polymerization. Nanopatterned brushes (NPBs) line with pattern sizes ranging from 50 to 200 nm are generated by patterning the initiator layer using deep-ultraviolet photolithography followed by brush growth initiated from the patterned layer. Homogeneous PEBs with different degrees of charging and grafting densities are exposed to water and salt solutions with different temperatures for different periods. The degradation is monitored through dry-state ellipsometry and atomic force microscopy measurements. Enhanced degrafting for more strongly swollen polymer brushes can be observed in agreement with an "entropic spring" model. Based on the results of the nonpatterned brushes, the NPBs are exposed to water at different temperatures and external salt content for varying periods of time. Counterintuitively, the NPBs show increased degrafting for smaller patterns, which is attributed to different polymer chain dynamics for nanobrushes and microbrushes. We investigate the influence of thermodynamic and kinetic parameters on the stability of (nanopatterned) PEBs and discuss the role of entanglements and formation of complexes in such films. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1283-1295