Centre de Recherche du C.H.U.Q., 10 rue de l'Espinay, Québec, Québec G1L 3L5, Canada.
ACS Appl Mater Interfaces. 2011 Mar;3(3):750-8. doi: 10.1021/am1010964. Epub 2011 Mar 7.
Fog formation on transparent substrates constitutes a major challenge in several optical applications requiring excellent light transmission characteristics. Anti-fog coatings are hydrophilic, enabling water to spread uniformly on the surface rather than form dispersed droplets. Despite the development of several anti-fog coating strategies, the long-term stability, adherence to the underlying substrate, and resistance to cleaning procedures are not yet optimal. We report on a polymer-based anti-fog coating covalently grafted onto glass surfaces by means of a multistep process. Glass substrates were first activated by plasma functionalization to provide amino groups on the surface, resulting in the subsequent covalent bonding of the polymeric layers. The anti-fog coating was then created by the successive spin coating of (poly(ethylene-maleic anhydride) (PEMA) and poly(vinyl alcohol) (PVA) layers. PEMA acted as an interface by covalently reacting with both the glass surface amino functionalities and the PVA hydroxyl groups, while PVA added the necessary surface hydrophilicity to provide anti-fog properties. Each step of the procedure was monitored by XPS, which confirmed the successful grafting of the coating. Coating thickness was evaluated by profilometry, nanoindentation, and UV visible light transmission. The hydrophilic nature of the anti-fog coating was assessed by water contact angle (CA), and its anti-fog efficiency was determined visually and tested quantitatively for the first time using an ASTM standard protocol. Results show that the PEMA/PVA coating not only delayed the initial period required for fog formation but also decreased the rate of light transmission decay. Finally, following a 24 hour immersion in water, these PEMA/PVA coatings remained stable and preserved their anti-fog properties.
在需要出色透光特性的若干光学应用中，透明基底上的雾形成是一个重大挑战。防雾涂层具有亲水性，使水能够在表面上均匀展开，而不是形成离散的液滴。尽管已经开发出几种防雾涂层策略，但长期稳定性、与底层基底的附着力以及对清洁程序的抵抗力仍不尽如人意。我们报告了一种通过多步过程共价接枝到玻璃表面的基于聚合物的防雾涂层。首先通过等离子体功能化使玻璃基底活化，在表面上提供氨基，从而导致随后的聚合物层的共价键合。然后通过（聚（乙烯-马来酸酐）（PEMA）和聚乙烯醇（PVA）层的连续旋涂来制备防雾涂层。PEMA 通过与玻璃表面氨基官能团和 PVA 羟基共价反应充当界面，而 PVA 则增加了所需的表面亲水性以提供防雾性能。通过 XPS 监测程序的每个步骤，确认了涂层的成功接枝。通过轮廓仪、纳米压痕和 UV 可见光透射率评估涂层厚度。通过水接触角（CA）评估防雾涂层的亲水性质，并首次使用 ASTM 标准协议进行视觉评估和定量测试其防雾效率。结果表明，PEMA/PVA 涂层不仅延迟了雾形成所需的初始时间，而且还降低了光传输衰减的速度。最后，在浸入水中 24 小时后，这些 PEMA/PVA 涂层仍然稳定并保持其防雾性能。
