Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI-80101, Joensuu, Finland.
Langmuir. 2012 Oct 16;28(41):14747-55. doi: 10.1021/la303358h. Epub 2012 Oct 4.
Superhydrophobic polymer surfaces are typically fabricated by combining hierarchical micro-nanostructures. The surfaces have a great technological potential because of their special water-repellent and self-cleaning properties. However, the poor mechanical robustness of such surfaces has severely limited their use in practical applications. This study presents a simple and swift mass production method for manufacturing hierarchically structured polymer surfaces at micrometer scale. Polypropylene surface structuring was done using injection molding, where the microstructured molds were made with a microworking robot. The effect of the micro-microstructuring on the polymer surface wettability and mechanical robustness was studied and compared to the corresponding properties of micro-nanostructured surfaces. The static contact angles of the micro-microstructured surfaces were greater than 150° and the contact angle hysteresis was low, showing that the effect of hierarchy on the surface wetting properties works equally well at micrometer scale. Hierarchically micro-microstructured polymer surfaces exhibited the same superhydrophobic wetting properties as did the hierarchically micro-nanostructured surfaces. Micro-microstructures had superior mechanical robustness in wear tests as compared to the micro-nanostructured surfaces. The new microstructuring technique offers a precisely controlled way to produce superhydrophobic wetting properties to injection moldable polymers with sufficiently high intrinsic hydrophobicity.
超疏水聚合物表面通常通过结合分级微纳结构来制备。由于其特殊的疏水性和自清洁特性，这些表面具有巨大的技术潜力。然而，这种表面的机械强度差严重限制了它们在实际应用中的使用。本研究提出了一种简单快捷的大规模生产方法，可在微米尺度上制造分级结构的聚合物表面。使用注塑成型对聚丙烯表面进行结构化处理，其中使用微加工机器人制造微结构化模具。研究了微-微结构化对聚合物表面润湿性和机械强度的影响，并将其与相应的微纳结构化表面的性能进行了比较。微-微结构化表面的静态接触角大于 150°，接触角滞后低，表明在微米尺度上，分层对表面润湿性的影响同样有效。分级微-微结构化聚合物表面表现出与分级微纳结构化表面相同的超疏水性润湿特性。与微纳结构化表面相比，微-微结构化在磨损测试中具有更好的机械强度。与微纳结构化表面相比，新的微结构技术为具有足够高固有疏水性的可注塑聚合物提供了一种精确控制的生产超疏水性润湿特性的方法。
