Supplementary information file for: Artificial linear brush abrasion of coatings for photovoltaic module first-surfaces

Supplementary information file for: Artificial linear brush abrasion of coatings for photovoltaic module first-surfacesNatural soiling and the subsequent requisite cleaning of photovoltaic (PV) modules result in abrasion damage to the cover glass. The durability of the front glass has important economic consequences, including determining the use of anti-reflective and/or anti-soiling coatings as well as the method and frequency of operational maintenance (cleaning). Artificial linear brush abrasion using Nylon 6/12 bristles was therefore examined to explore the durability of representative PV first-surfaces, i.e., the surface of a module incident to direct solar radiation. Specimens examined include silane surface functionalized-, roughened (etched)-, porous silica-coated-, fluoropolymer-coated-, and ceramic (TiO2 or ZrO2/SiO2/ZrO2/SiO2)-coated-glass, which are compared to monolithic-poly(methyl methacrylate) and -glass coupons. Characterization methods used in this study include: optical microscopy, ultraviolet–visible–near-infrared (UV-VIS-NIR) spectroscopy, sessile drop goniometry, white-light interferometry, atomic force microscopy (AFM), and depth-profiling X-ray photoelectron spectroscopy (XPS). The corresponding characteristics examined include: surface morphology, transmittance (i.e., optical performance), surface energy (water contact angle), surface roughness, scratch width and depth, and chemical composition, respectively. The study here was performed to determine coating failure modes; identify characterization methods that can detect nascent failures; compare the durability of popular contemporary coating materials; identify their corresponding damage characteristics; and compare slurry and dry-dust abrasion. This study will also aid in developing an abrasion standard for the PV industry.

补充信息文件：光伏模块第一表面的人工线性刷磨涂层磨损及其后续必要的清洁。光伏（PV）模块的自然沾污及其随后的清洁作业导致了覆盖玻璃的磨损损害。前玻璃的耐用性具有重要的经济影响，包括确定使用抗反射和/或抗沾污涂层以及操作维护（清洁）的方法和频率。因此，采用尼龙6/12刷毛进行人工线性刷磨实验，以探究代表性光伏第一表面的耐用性，即直接太阳辐射照射到的模块表面。所检验的样品包括硅烷表面功能化、粗糙化（刻蚀）、多孔二氧化硅涂层、氟聚合物涂层以及陶瓷（TiO2或ZrO2/SiO2/ZrO2/SiO2）涂层玻璃，并与均质聚甲基丙烯酸甲酯和玻璃样板进行比较。本研究中使用的表征方法包括：光学显微镜、紫外-可见-近红外（UV-VIS-NIR）光谱学、静止液滴测角仪、白光干涉仪、原子力显微镜（AFM）和深度剖析X射线光电子能谱（XPS）。所考察的相应特征包括：表面形貌、透射率（即光学性能）、表面能（水接触角）、表面粗糙度、划痕宽度和深度以及化学组成。本研究旨在确定涂层失效模式；识别能够检测初始失效的表征方法；比较流行当代涂层材料的耐用性；识别其相应的损害特征；并比较浆料和干粉尘磨损。本研究还将有助于制定光伏行业的磨损标准。