Mandal Priya, Singh Vikramjeet, Zhang Jianhui, Tiwari Manish K
Nanoengineered Systems Laboratory, UCL Mechanical Engineering, University College London London WC1E 7JE U.K
Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London London W1W 7TS U.K.
Environ Sci Nano. 2025 Jan 29;12(3):1930-1941. doi: 10.1039/d4en00762j. eCollection 2025 Mar 13.
Transparent non-wetting surfaces with mechanical robustness are critical for applications such as contamination prevention, (anti-)condensation, anti-icing, anti-biofouling, The surface treatments in these applications often use hazardous per- and polyfluoroalkyl substances (PFAS), which are bio-persistent or have compromised durability due to weak polymer/particle interfacial interactions. Hence, developing new approaches to synthesise non-fluorinated liquid-repellent coatings with attributes such as scalable fabrication, transparency, and mechanical durability is important. Here, we present a water-based spray formulation to fabricate non-fluorinated amphiphobic (repellent to both water and low surface tension liquids) coatings by combining polyurethane and porous metal-organic frameworks (MOFs) followed by post-functionalisation with flexible alkyl silanes. Owing to intercalation of polyurethane chains into MOF pores, akin to robust bicontinuous structures in nature, these coatings show excellent impact robustness, resisting high-speed water jets (∼35 m s), and a very low ice adhesion strength of ≤30 kPa across multiple icing/de-icing cycles. These surfaces are also smooth and highly transparent, and exhibit excellent amphiphobicity towards a range of low surface tension liquids from water to alcohols and ketones. The multi-functionality, robustness and potential scalability of our approach make this formulation a good alternative to hazardous PFAS-based coatings or solid particle/polymer nanocomposites.
具有机械稳健性的透明不润湿表面对于诸如防止污染、（抗）冷凝、防冰、抗生物污垢等应用至关重要。这些应用中的表面处理通常使用有害的全氟和多氟烷基物质（PFAS），这些物质具有生物持久性或由于聚合物/颗粒界面相互作用较弱而耐久性受损。因此，开发新的方法来合成具有可扩展制造、透明度和机械耐久性等特性的非氟化拒液涂层非常重要。在这里，我们提出了一种水基喷雾配方，通过将聚氨酯和多孔金属有机框架（MOF）结合，然后用柔性烷基硅烷进行后功能化，来制造非氟化双疏（对水和低表面张力液体都具有排斥性）涂层。由于聚氨酯链插入MOF孔中，类似于自然界中坚固的双连续结构，这些涂层表现出出色的抗冲击稳健性，能够抵抗高速水射流（约35米/秒），并且在多个结冰/除冰循环中具有≤30 kPa的极低冰粘附强度。这些表面也很光滑且高度透明，并且对从水到醇和酮等一系列低表面张力液体表现出优异的双疏性。我们方法的多功能性、稳健性和潜在可扩展性使这种配方成为基于PFAS的有害涂层或固体颗粒/聚合物纳米复合材料的良好替代品。
