Understanding the kinetic pathways of self-assembly in block copolymers (BCPs) has been a long-standing challenge, mostly due to limitations of in situ monitoring techniques. Here, we demonstrate an approach that uses optical birefringence, determined by spectroscopic ellipsometry (SE), as a measure of domain formation in cylinder- and lamellae-forming BCP films. The rapid experimental acquisition time in SE (ca. 1 sec) enables monitoring of the assembly/disassembly kinetics of BCP films during solvent-vapor annealing (SVA). We demonstrate that upon SVA, BCP films form ordered domains that are stable in the swollen state, but disorder upon rapid drying. Surprisingly, the disassembly during drying strongly depends on the duration of solvent exposure in the swollen state, explaining previous observations of loss of order in SVA processes. SE thus allows for decoupling of BCP self-assembly and disordering that occurs during solvent annealing and solvent evaporation, which is difficult to probe using other, slower techniques.

中文翻译：

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使用原位光谱椭偏仪对嵌段共聚物自组装进行动力学监测

了解嵌段共聚物 (BCP) 中自组装的动力学途径一直是一项长期挑战，主要是由于原位监测技术的局限性。在这里，我们展示了一种使用光学双折射的方法，该方法由光谱椭偏仪 (SE) 确定，作为圆柱和薄片形成 BCP 薄膜中域形成的量度。SE 中的快速实验采集时间（约 1 秒）能够监测溶剂蒸汽退火 (SVA) 期间 BCP 薄膜的组装/拆卸动力学。我们证明，在 SVA 上，BCP 薄膜形成有序域，在膨胀状态下稳定，但在快速干燥时无序。令人惊讶的是，干燥过程中的拆卸很大程度上取决于溶胀状态下溶剂暴露的持续时间，这解释了之前对 SVA 工艺中秩序损失的观察。