Department of Materials Science and Engineering, Kyoto University , Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
Langmuir. 2017 Oct 17;33(41):10829-10837. doi: 10.1021/acs.langmuir.7b02739. Epub 2017 Oct 4.
Through 172 nm vacuum ultraviolet light irradiation in a high vacuum condition (HV-VUV), well-defined micropatterns with a varied periodic friction were fabricated at the surface of self-assembled monolayers (SAMs) terminated with oxygenated groups. No apparent height contrast between the HV-VUV-irradiated and -masked areas was observed, which indicated the stability of the C-C skeleton of the assembled molecules. The trimming of oxygenated groups occurred through dissociating the C-O bonds and promoting the occurrence of α- and β-cleavages in the C═O-containing components. Hence, the HV-VUV treatment trimmed the oxygenated groups without degrading the C-C skeleton. The HV-VUV treatment influenced the order of the assembled molecules, and the step-terrace structure was distorted. The decrease in friction at the HV-VUV-irradiated domains was attributed to the dissociation of oxygenated groups. (3-Aminopropyl)trimethoxysilane (APTMS) aggregated at the masked areas of the HV-VUV-patterned SAM, where the oxygenated groups worked as anchors. APTMS aggregations did not exist at the irradiated areas, indicating the trimming of the oxygenated groups at these areas. The direct assembling of APTMS on the Si substrate at the irradiated areas was prevented by the remaining C-C skeleton.
通过在高真空条件下用 172nm 真空紫外光（HV-VUV）辐照，在含氧基团封端的自组装单层（SAM）表面制备了具有不同周期摩擦的明确定义的微图案。在 HV-VUV 辐照和掩蔽区域之间没有观察到明显的高度对比，这表明了组装分子的 C-C 骨架的稳定性。含氧基团的修剪是通过解离 C-O 键并促进 C═O 含成分中的α-和β-裂解来实现的。因此，HV-VUV 处理修剪了含氧基团而不降解 C-C 骨架。HV-VUV 处理影响了组装分子的有序性，并且阶梯地形结构被扭曲。在 HV-VUV 辐照区域摩擦的降低归因于含氧基团的解离。（3-氨丙基）三甲氧基硅烷（APTMS）在 HV-VUV 图案化 SAM 的掩蔽区域聚集，其中含氧基团作为锚。在辐照区域不存在 APTMS 聚集，表明这些区域的含氧基团被修剪。在辐照区域，剩余的 C-C 骨架阻止了 APTMS 直接在 Si 衬底上组装。
