van Engers Christian D, Lamberty Zachary D, McGuiggan Patricia M, Frechette Joelle
Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States.
Langmuir. 2021 Jun 1;37(21):6556-6565. doi: 10.1021/acs.langmuir.1c00899. Epub 2021 May 19.
We present a method for the fabrication of ultra-smooth (0.2 nm RMS), aluminum substrates through template stripping (TS). The method relies on the use of mica as a template in combination with thermal evaporation of Al at high (>10 nm/s) rates under vacuum (≤1 × 10 Torr). As a reactive metal, Al is usually not considered a viable option for TS off oxide templates. However, under these conditions, the adhesion between the Al film and mica is poor, enabling the removal of the template under water without any mica residue. We verify the absence of mica using atomic force microscopy, X-ray photoelectron spectroscopy, and contact angle measurements. We establish the suitability of these films for surface forces measurements. Multiple-bean interferometry in transmission yields high quality fringes allowing for the measurement of force-distance curves. The adhesion the films to mica is significantly higher than the adhesion of thermally evaporated Al (0.9 nm RMS). Preliminary results suggest that the TS-Al surface displays a higher corrosion resistance. The fabrication method will enable important experiments on this widely used material.
我们展示了一种通过模板剥离（TS）制造超光滑（均方根粗糙度为0.2纳米）铝基板的方法。该方法依赖于使用云母作为模板，并在真空（≤1×10托）下以高（>10纳米/秒）速率热蒸发铝。作为一种活性金属，铝通常不被认为是从氧化物模板上进行模板剥离的可行选择。然而，在这些条件下，铝膜与云母之间的附着力较差，使得在水下能够去除模板且没有任何云母残留。我们使用原子力显微镜、X射线光电子能谱和接触角测量来验证云母的不存在。我们确定了这些薄膜适用于表面力测量。透射式多光束干涉测量产生高质量条纹，可用于测量力-距离曲线。这些薄膜与云母的附着力明显高于热蒸发铝（均方根粗糙度为0.9纳米）。初步结果表明，模板剥离铝表面具有更高的耐腐蚀性。该制造方法将使对这种广泛使用的材料进行重要实验成为可能。
