School of Chemistry & Chemical Engineering, Frontiers Science Center for Transformative Molecules, State Key Laboratory for Metal Matrix Composite Materials, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Chemistry. 2021 Mar 26;27(18):5810-5816. doi: 10.1002/chem.202100189. Epub 2021 Mar 1.
Wrinkles and photo-oxidation reactions are widely found in soft materials, which are intimately associated with the failure of materials and structures. It is expected that the photo-oxidation process could also have a positive effect on the material and its surface. Here, we report the photo-oxidation of 2-(4-dietheylaminophenyl)-4,5-bis(4-methoxyphenyl) imidazole (DEA-TAI) into a wrinkled bilayer system to control surface wrinkle and fluorescent patterns, in which a supramolecular polymer network composed of carboxylic acid-containing copolymer (PS-BA-AA; PS=poly(styrene), BA=butyl acrylate; AA=acrylic acid) and DEA-TAI were used as the skin layer. Ultraviolet (UV) irradiation can induce photo-oxidation of the imidazole ring of DEA-TAI to weaken the intermolecular hydrogen bonding between PS-BA-AA and DEA-TAI, resulting in the release of stress in the bilayer system. The wrinkled morphology and fluorescence of the surface can be simultaneously regulated by photo-oxidation of DEA-TAI under UV light, and the resulting wrinkles are extremely sensitive to the pH value, which can be quickly and reversibly erased by NH gas. Smart surfaces with specific hierarchical wrinkles and fluorescence can be achieved by selective irradiation with photomasks, which may find potential applications in smart displays and multi-code information storage.
皱纹和光氧化反应在软材料中广泛存在，与材料和结构的失效密切相关。预计光氧化过程也可能对材料及其表面产生积极影响。在这里，我们报告了 2-(4-二乙氨基苯基)-4,5-双(4-甲氧基苯基)咪唑（DEA-TAI）的光氧化反应，形成了一个具有皱纹的双层体系，以控制表面皱纹和荧光图案，其中含有羧酸的超分子聚合物网络共聚物（PS-BA-AA；PS=聚苯乙烯，BA=丙烯酸丁酯；AA=丙烯酸）和 DEA-TAI 作为皮层。紫外线（UV）照射可以诱导 DEA-TAI 中咪唑环的光氧化，从而削弱 PS-BA-AA 和 DEA-TAI 之间的分子间氢键，导致双层体系中的应力释放。在紫外光下，DEA-TAI 的光氧化可以同时调节表面的皱纹形貌和荧光，得到的皱纹对 pH 值极其敏感，可以通过 NH 气体快速可逆地擦除。通过选择性使用光掩模进行照射，可以实现具有特定分级皱纹和荧光的智能表面，这可能在智能显示和多码信息存储方面有潜在的应用。
