Schedl Andreas E, Probst Patrick T, Meichner Christoph, Neuber Christian, Kador Lothar, Fery Andreas, Schmidt Hans-Werner
Department of Macromolecular Chemistry I and Bavarian Polymer Institute, University of Bayreuth, 95440 Bayreuth, Germany.
Soft Matter. 2019 May 15;15(19):3872-3878. doi: 10.1039/c8sm02585a.
Alignment of nanoparticles to hierarchical periodic structures is an emerging field in the development of patterned surfaces. Common alignment methods are based on templates that guide particle self-assembly. These can be formed using lithographic methods offering an almost free choice of the motif, while being expensive and time-consuming for large-scale production. Alternatively, template formation by controlled wrinkling offers a low-cost formation, but often suffers from the formation of defect structures like line-defects and cracks. Here, we show a preparation technique for nanoparticle alignment substrates that is based on the inscription of holographic surface relief gratings with a periodic sinusoidal wave pattern on the surface of azobenzene films. As interference patterns are employed for structure formation, very uniform and defect-free gratings with tunable grating height and grating period can be prepared. These substrates were successfully replicated to poly(dimethyl siloxane) and the replicas used for the alignment of polystyrene latex particles. Accordingly produced substrates exhibiting gratings with a variation in grating height allow for efficient screening of nanoparticle alignment in a geometrical confinement in one single experiment. We anticipate our studies as a promising tool for the development of sensors, tunable gratings and metamaterials.
将纳米颗粒排列成分层周期性结构是图案化表面开发中的一个新兴领域。常见的排列方法基于引导颗粒自组装的模板。这些模板可以使用光刻方法形成，图案几乎可以自由选择，但大规模生产时成本高昂且耗时。另外，通过可控褶皱形成模板成本较低，但常常会出现诸如线缺陷和裂纹等缺陷结构。在此，我们展示了一种用于纳米颗粒排列基板的制备技术，该技术基于在偶氮苯薄膜表面刻写具有周期性正弦波图案的全息表面浮雕光栅。由于利用干涉图案来形成结构，因此可以制备出具有可调光栅高度和光栅周期的非常均匀且无缺陷的光栅。这些基板成功复制到聚二甲基硅氧烷上，所得复制品用于聚苯乙烯乳胶颗粒的排列。相应制备出的具有光栅高度变化的光栅的基板，能够在单个实验中的几何限制条件下高效筛选纳米颗粒排列情况。我们预计我们的研究将成为开发传感器、可调光栅和超材料的一种有前景的工具。
