Nanoscopic mechanical tests for characterizing forces during UVinitiated mass transport in photosensitive polymer films

我们的目的是通过观察吸附在金层上的薄层的机械响应来表征偶氮改性光敏物理吸附聚合物薄膜和刷子系统在形貌变化时产生的热化学力。偶氮修饰的光敏聚合物提供了一种有趣的可能性，可以在固体玻璃状态下通过紫外光照射来重塑本体聚合物和薄膜的形状。在生色团的区域形成过程中，聚合物经历了相当大的传质过程。我们对物理吸附光敏薄膜和刷子系统的比较研究表明，在刷子中，由于其限制了单链的动力学，表现出更强的响应。将地形图案刻在薄膜上的作用力很难直接通过实验进行评估。然而，我们的结果表明，它们可以在薄的吸附金层上引起强烈的变形。在这项工作中，我们将结合原子力显微镜成像，使用两种新的方法，共焦拉曼技术和红外近场技术，来空间解析金-聚合物杂化体系的组成，并定量地表征不同厚度的金层上的薄膜所能做的机械功。在下文中，我们还将尝试表征聚合物薄膜本身的化学成分，并得出关于刻划力起源的详细的分子图像。

We aim at characterizing the thermochemical forces emerging during topography changes of azo-modified photosensitive physisorbed polymer films and brush systems by looking at the mechanical response of thin adsorbed gold layers. Azo-modified photosensitive polymers offer the interesting possibility to reshape bulk polymers and thin films by UV-irradiation while being in the solid glassy state. The polymer undergoes considerable mass transport during domain formation of chromophores. Our comparative studies on physisorbed photosensitive thin films and brush systems indicate, that in brushes with their restricted dynamics of single chains show a much stronger response. The forces inscribing a topographical pattern into a thin film are hard to assess experimentally directly. Our results, however, indicate that they can give rise to strong deformation on thin adsorbed gold layers. In this work, we are going to employ, along with AFM imaging, two new methods, confocal Raman and IR-nearfield techniques, for spatially resolving the composition of the hybrid gold-polymer system and quantitatively characterize the mechanical work that can be done by a film on gold layers of varying thickness. In the following, we shall also attempt to characterize the chemical composition of the polymer film itself and arrive at a detailed molecular picture of the origin of inscribing forces.