Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Phys Chem Chem Phys. 2021 Mar 11;23(9):5516-5526. doi: 10.1039/d0cp04796a.
Bio-inspired polydopamine coatings offer vast possibilities for surface modification of materials. The thickness of such nanometric coatings is usually estimated based on ellipsometry measurements. However, the complex light-absorbing nature of polydopamine is often overlooked when analyzing such data, which can result in inaccurate estimations of the coating thickness as well as the optical properties. In this study, we prepared and characterized three polydopamine coatings where the film thickness and surface roughness are systematically varied. For each case, we developed suitable optical models and showed how an inappropriate optical model can provide inaccurate estimates of the coating properties. AFM height profiles were obtained from scratched areas of each sample to verify the thickness values estimated by ellipsometry. The results confirm that polydopamine coatings, depending on the oxidation conditions, can possess different structural and optical properties, and thus require unique optical models for the ellipsometry analysis.
仿生聚多巴胺涂层为材料的表面改性提供了广阔的可能性。这种纳米级涂层的厚度通常基于椭偏测量来估计。然而，在分析此类数据时，往往会忽略聚多巴胺复杂的吸光性质，这可能导致涂层厚度以及光学性质的不准确估计。在本研究中，我们制备并表征了三种聚多巴胺涂层，其膜厚和表面粗糙度得到了系统的改变。对于每种情况，我们都开发了合适的光学模型，并展示了不适当的光学模型如何提供涂层性质的不准确估计。从每个样品的划痕区域获得 AFM 高度轮廓，以验证椭偏测量所估计的涂层厚度值。结果证实，聚多巴胺涂层根据氧化条件的不同，可以具有不同的结构和光学性质，因此需要为其椭偏分析建立独特的光学模型。
