Macdonald Brian, Wang Fan-Wei, Tobelmann Brian, Wang Jing, Landini Jason, Gunaratne Nipuli, Kovac Joseph, Miller Todd, Mosurkal Ravi, Tuteja Anish
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
ACS Appl Mater Interfaces. 2024 Mar 13;16(10):13018-13028. doi: 10.1021/acsami.3c17117. Epub 2024 Mar 5.
Fog formation is a common challenge for numerous applications, such as food packaging, mirrors, building windows, and freezer/refrigerator doors. Most notably, fog forms on the inner surfaces of prescription glasses and safety eyewear (particularly when used with a mask), face shields, and helmet lenses. Fogging is caused by the distortion of light from condensed water droplets present on a surface and can typically be prevented if the surface static water contact angle (θ) is less than ∼40°. Such a low contact angle can be readily achieved by either increasing the substrate surface energy or by engineering surface nanotexture. Unfortunately, such nanotexture can be readily damaged with use, while high surface energy substrates get covered with low surface energy foulants over time. Consequently, even with numerous ephemeral antifog coatings, currently there are no commercially available, durable, and permanent antifog coatings. Here we discuss the development of a new class of high-performance antifog coatings that are abrasion-resistant and long-lasting. These polyvinylpyrrolidone-based coatings, designed based on the classical Ratner-Lancaster wear model, dramatically outperform the base polymer, as well as all tested commercially available antifog coatings. Specifically, these coatings exhibit a > 400% increase in fogging time compared to base polymer, a > 50,000% increase in wear resistance, and excellent long-term antifog performance. The developed coatings also significantly outperformed all tested commercially available antifog coatings in terms of their antifog performance, wear resistance, and long-term cyclical performance. Additionally, the key design strategies employed here─incorporation of toughening agents and hydrophilic slip additives─offer a new approach to developing high-performance, durable antifog coatings based on other well-known antifog polymers.
起雾是众多应用中常见的挑战，如食品包装、镜子、建筑窗户以及冷冻柜/冰箱门等。最值得注意的是，雾气会在处方眼镜和安全眼镜（特别是与口罩一起使用时）、面罩及头盔镜片的内表面形成。起雾是由表面存在的冷凝水滴使光线发生畸变所致，通常如果表面静态水接触角（θ）小于约40°，就能防止起雾。通过增加基材表面能或设计表面纳米纹理，可轻松实现如此低的接触角。不幸的是，这种纳米纹理在使用过程中很容易受损，而高表面能基材随着时间推移会被低表面能污垢覆盖。因此，即便有众多临时性的防雾涂层，但目前尚无商业可用的、耐用且持久的防雾涂层。在此，我们讨论一类新型高性能防雾涂层的研发，这类涂层具有耐磨且持久的特性。这些基于聚乙烯吡咯烷酮的涂层，是根据经典的拉特纳 - 兰卡斯特磨损模型设计的，其性能显著优于基础聚合物以及所有经测试的市售防雾涂层。具体而言，与基础聚合物相比，这些涂层的起雾时间增加了400%以上，耐磨性提高了50000%以上，并且具有出色的长期防雾性能。在防雾性能、耐磨性和长期循环性能方面，所研发的涂层也明显优于所有经测试的市售防雾涂层。此外，这里采用的关键设计策略——加入增韧剂和亲水防滑添加剂——为基于其他知名防雾聚合物开发高性能、耐用的防雾涂层提供了一种新方法。
