Department of Chemistry, University of Eastern Finland , P.O. Box 111, FI-80101, Joensuu, Finland.
Langmuir. 2014 Feb 11;30(5):1435-43. doi: 10.1021/la404248d. Epub 2014 Jan 31.
Considerable attention is currently being devoted less to the question of whether it is possible to produce superhydrophobic polymer surfaces than to just how robust they can be made. The present study demonstrates a new route for improving the mechanical durability of water-repellent structured surfaces. The key idea is the protection of fragile fine-scale surface topographies against wear by larger scale sacrificial micropillars. A variety of surface patterns was manufactured on polypropylene using a microstructuring technique and injection molding. The surfaces subjected to mechanical pressure and abrasive wear were characterized by water contact and sliding angle measurements as well as by scanning electron microscopy and roughness analysis based on optical profilometry. The superhydrophobic polypropylene surfaces with protective structures were found to maintain their wetting properties in mechanical compression up to 20 MPa and in abrasive wear tests up to 120 kPa. For durable properties, the optimal surface density of the protective pillars was found to be about 15%. The present approach to the production of water-repellent polymer surfaces provides the advantages of mass production and mechanical robustness with practical applications of structurally functionalized surfaces.
目前，人们越来越关注如何提高超疏水聚合物表面的机械耐久性，而不是仅仅关注是否有可能制造出超疏水聚合物表面。本研究提出了一种提高疏水性结构化表面机械耐久性的新方法。其关键思想是通过较大尺度的牺牲性微柱来保护易碎的精细表面形貌免受磨损。通过微结构技术和注塑成型在聚丙烯上制造了各种表面图案。通过水接触和滑动角测量以及扫描电子显微镜和基于光学轮廓术的粗糙度分析，对经受机械压力和磨料磨损的表面进行了表征。具有保护结构的超疏水聚丙烯表面在机械压缩下可保持其润湿性能，直至 20 MPa，在磨损试验中可保持其润湿性能，直至 120 kPa。对于耐用性，发现最佳的保护柱表面密度约为 15%。本研究提出的生产疏水性聚合物表面的方法具有大规模生产和机械坚固性的优点，并可实际应用于结构功能化表面。
