In this work, ordered patterns having nanoscale features and resolutions in the range of 5–75 μm are produced from thin films of azo-polyurea (azo-PU) using photoinduced dewetting. Azo-PU is synthesized through polyaddition reactions, and reversible isomerization between cis – trans states is demonstrated by exposure to light of wavelengths 365 and 450 nm. This photochemical response is exploited to produce patterns by selective exposure using photomasks followed by subsequent annealing to induce polymer flow and dewetting. Marangoni flow is found to be a dominant mechanism that controls morphological evolution of patterns. The patterns can be switched between pillar-like and hole-like morphologies by stimulating the forward or backward isomerization reaction, and pattern resolution can be controlled using photomasks of different feature sizes. Preferential adsorption of proteins on these patterns is proposed as a potential application.

在这项工作中，使用光致去湿法从偶氮聚脲 (azo-PU) 薄膜产生具有纳米级特征和分辨率在 5-75 μm 范围内的有序图案。Azo-PU 是通过加聚反应合成的，并且通过暴露于波长 365 和 450 nm 的光来证明顺式 - 反式之间的可逆异构化。利用这种光化学反应，通过使用光掩模进行选择性曝光，然后进行退火以诱导聚合物流动和去湿来产生图案。发现 Marangoni 流是控制模式形态演化的主要机制。通过刺激正向或反向异构化反应，可以在柱状和孔状形态之间切换图案，并且可以使用不同特征尺寸的光掩模来控制图案分辨率。