Chain Movements of a Molecularly Flat PMMA Substrate Surface Prepared by Thermal Imprinting with Mica and Isolated PMMA Chains Deposited on the PMMA Substrate Observed by AFM around the Bulk Tg
Chain Movements of a Molecularly Flat PMMA Substrate Surface Prepared by Thermal Imprinting with Mica and Isolated PMMA Chains Deposited on the PMMA Substrate Observed by AFM around the Bulk Tg
复制标题
通过云母热压印制备的分子平坦 PMMA 基材表面的链运动以及沉积在 PMMA 基材上的独立 PMMA 链，通过 AFM 在整体 Tg 周围观察到
DOI：
10.1038/s41428-021-00600-0
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Jiro Kumaki
中科院分区：
文献类型：
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作者：
Jin Ohkawa;Jiro Kumaki
聚合物材料的表面热力学不稳定，其玻璃化转变温度（Tg）明显低于本体值。然而，聚合物材料最表面的链的移动性从未被直接评估过。在这项研究中，我们通过用云母热压印2毫米厚的PMMA板制备了聚甲基丙烯酸甲酯（PMMA）分子平面基板，通过Langmuir-Blodgett技术在其上沉积了孤立的PMMA链，并通过原位高温原子力显微镜在分子水平上评估了表面的热稳定性。孤立的 PMMA 链开始移动并聚集到大块 PMMATg 附近。此外，在PMMA板表面观察到的5-7 nm宽的纳米结构开始向bulkTg移动，表明PMMA板表面的链也开始向bulkTg移动。此外，还讨论了粗糙 PMMA 表面链可视化的可能性。
The surface of polymer materials is thermodynamically unstable, and its glass transition temperature (Tg) is known to be significantly lower than the bulk value. However, the mobility of the chains at the topmost surface of polymer materials has never been directly evaluated. In this study, we prepared a molecularly flat substrate of poly(methyl methacrylate) (PMMA) by thermally imprinting a 2 mm-thick PMMA plate with mica, on which isolated PMMA chains were deposited by the Langmuir–Blodgett technique, and the thermal stability of the surface was evaluated by in situ high-temperature atomic force microscopy at the molecular level. The isolated PMMA chains started to move and aggregate close to the bulk PMMATg. In addition, 5–7 nm-wide nanostructures that were observed at the surface of the PMMA plate started to move close to the bulkTg, indicating that the chains at the surface of the PMMA plate also start to move close to the bulkTg. In addition, the possibility of chain visualization at rough PMMA surface is also discussed.