Smart Materials, Istituto Italiano di Tecnologia , Genoa 16163, Italy.
Nanophysics Department, Istituto Italiano di Tecnologia , Genoa 16163, Italy.
ACS Appl Mater Interfaces. 2018 Jan 24;10(3):2907-2917. doi: 10.1021/acsami.7b15088. Epub 2018 Jan 9.
Superhydrophobic materials hold an enormous potential in sectors as important as aerospace, food industries, or biomedicine. Despite this great promise, the lack of environmentally friendly production methods and limited robustness remain the two most pertinent barriers to the scalability, large-area production, and widespread use of superhydrophobic materials. In this work, highly robust superhydrophobic silicone monoliths are produced through a scalable and environmentally friendly emulsion technique. It is first found that stable and surfactantless water-in-polydimethylsiloxane (PDMS) emulsions can be formed through mechanical mixing. Increasing the internal phase fraction of the precursor emulsion is found to increase porosity and microtexture of the final monoliths, rendering them superhydrophobic. Silica nanoparticles can also be dispersed in the aqueous internal phase to create micro/nanotextured monoliths, giving further improvements in superhydrophobicity. Due to the elastomeric nature of PDMS, superhydrophobicity can be maintained even while the material is mechanically strained or compressed. In addition, because of their self-similarity, the monoliths show outstanding robustness to knife-scratch, tape-peel, and finger-wipe tests, as well as rigorous sandpaper abrasion. Superhydrophobicity was also unchanged when exposed to adverse environmental conditions including corrosive solutions, UV light, extreme temperatures, and high-energy droplet impact. Finally, important properties for eventual adoption in real-world applications including self-cleaning, stain-repellence, and blood-repellence are demonstrated.
超疏水材料在航空航天、食品工业、生物医学等重要领域具有巨大的应用潜力。尽管具有广阔的应用前景，但缺乏环保的生产方法和有限的耐用性仍然是限制超疏水材料规模化、大面积生产和广泛应用的两大最主要障碍。在这项工作中，通过一种可扩展且环保的乳液技术制备了具有高耐用性的超疏水硅酮单体。首先发现，通过机械混合可以形成稳定且无表面活性剂的水/聚二甲基硅氧烷（PDMS）乳液。研究发现，增加前驱体乳液的内相分数可以增加最终单体的孔隙率和微观结构，从而使它们具有超疏水性。还可以将纳米二氧化硅颗粒分散在水相内部，从而形成微/纳米结构的单体，进一步提高超疏水性。由于 PDMS 的弹性性质，即使材料受到机械应变或压缩，超疏水性也能得以维持。此外，由于其自相似性，单体在经受刀刮、胶带剥离和手指擦拭以及严格的砂纸磨损等测试时表现出出色的耐用性。暴露于腐蚀性溶液、紫外光、极端温度和高能液滴冲击等恶劣环境条件下，超疏水性也保持不变。最后，展示了在实际应用中最终采用的重要特性，包括自清洁、防污和抗血液污染。
