Understanding the formation mechanism and conformation of the adsorbed film formed by additives is critical to clarify the boundary lubrication characteristics. In this study, using the vertical-objective-based ellipsometric microscope (VEM), which can measure nm-gaps between solid surfaces, we proposed a new method for in-situ measuring the thickness of additive adsorbed film in the lubricant oil. In this method, the adsorbed film thickness was measured by measuring the gap between the solids, which was filled by the additive film. The formation process of polyalkylmethacrylate (PAMA) polymer additive adsorbed film was successfully observed. Moreover, we revealed that the PAMA adsorbed films adopted two different conformations depending on the molecular weight and concentration of the polymer: the flattened single-layer conformation and double-layer conformation.

了解添加剂形成的吸附膜的形成机制和构象对于阐明边界润滑特性至关重要。在这项研究中，我们使用基于垂直物镜的椭偏显微镜 (VEM)，它可以测量固体表面之间的纳米间隙，我们提出了一种原位测量润滑油中添加剂吸附膜厚度的新方法。在该方法中，通过测量由添加剂膜填充的固体之间的间隙来测量吸附膜厚度。成功观察了聚甲基丙烯酸烷基酯（PAMA）聚合物添加剂吸附膜的形成过程。此外，我们发现 PAMA 吸附膜根据聚合物的分子量和浓度采用两种不同的构象：