Singh Vikramjeet, Men Xuehu, 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.
Nano Lett. 2021 Apr 28;21(8):3480-3486. doi: 10.1021/acs.nanolett.1c00157. Epub 2021 Apr 12.
Highly amphiphobic (repelling both water and low surface tension liquids) and optically transparent surface treatments have widespread demand. By combining a rational growth of metal-organic frameworks (MOFs) with functionalization by environmentally safe, flexible alkyl groups, here we present surfaces with nanohierarchical morphology, comprising two widely differing nanoscale features. These nanohierarchical MOF films show excellent amphiphobicity. We further present three key features. First, we demonstrate the need to use flexible alkyl chains to achieve low drop sliding angles and self-cleaning. Second, our thin (∼200 nm) MOF films display excellent optical transparency and robustness. Third, the nanohierarchical morphology enables a unique combination of additional desirable properties, e.g., resistance to high-speed liquid impact (up to ∼35 m/s, Weber number >4 × 10), thermal stability up to 200 °C, scratch resistance, low ice adhesion for >10 icing/deicing cycles, stability in harsh acidic and basic environments, and capability to remove carcinogenic pollutants from water.
高度憎水（排斥水和低表面张力液体）且光学透明的表面处理具有广泛的需求。通过将金属有机框架（MOF）的合理生长与环境安全的柔性烷基官能化相结合，我们在此展示了具有纳米分级形态的表面，其包含两种截然不同的纳米级特征。这些纳米分级MOF薄膜表现出优异的憎水性。我们还展示了三个关键特性。首先，我们证明了需要使用柔性烷基链来实现低液滴滑动角和自清洁。其次，我们的薄（约200纳米）MOF薄膜表现出优异的光学透明度和坚固性。第三，纳米分级形态能够实现其他理想特性的独特组合，例如，抵抗高速液体冲击（高达约35米/秒，韦伯数>4×10）、高达200°C的热稳定性、耐刮性、在>10次结冰/除冰循环中的低冰附着力、在苛刻的酸性和碱性环境中的稳定性以及从水中去除致癌污染物的能力。
