Maji Kousik, Das Avijit, Hirtz Michael, Manna Uttam
Department of Chemistry, Indian Institute of Technology-Guwahati, Kamrup, Assam 781039, India.
Institute of Nanotechnology (INT) & Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
ACS Appl Mater Interfaces. 2020 Mar 25;12(12):14531-14541. doi: 10.1021/acsami.9b22469. Epub 2020 Mar 13.
Design of Nepenthes pitcher-inspired slippery liquid-infused porous surface (SLIPS) appeared as an important avenue for various potential and practically relevant applications. In general, hydrophobic base layers were infused with selected liquid lubricants for developing chemically inert SLIPS. Here, in this current study, an inherently hydrophilic (soaked beaded water droplet with ∼20° within a couple of minutes), porous and thick (above 200 μm) polymeric coating, loaded with readily chemically reactive acrylate moieties yielded a chemically reactive SLIPS, where residual acrylate groups in the synthesized hydrophilic and porous interface rendered stability to the infused lubricants. The chemically reactive SLIPS is capable of reacting with the solution of primary amine-containing nucleophiles in organic solvent through 1,4-conjugate addition reaction, both in the presence (referred as "in situ" modification) and absence (denoted as pre-modification) of lubricated phase in the porous polymeric coating. Such amine reactive SLIPS was further extended to (1) examining the impact of different chemical modifications on the performance of SLIPS and (2) developing a spatially selective and "in situ" postmodification with primary amine-containing nucleophiles through 1,4-conjugate addition reaction. Moreover, the chemically reactive SLIPS was capable of sustaining various physical abrasions and prolonged (minimum 10 days) exposure to complex and harsh aqueous phases, where infused lubricants protect the residual acrylate groups from harsh aqueous exposures. Such, principle will be certainly useful for spatially selective covalent immobilization of water-insoluble functional molecules/polymers directly from organic solvents, which would be of potential interest for various applied and fundamental contexts.
受猪笼草捕虫笼启发设计的光滑液体注入多孔表面（SLIPS），成为各种潜在且具有实际意义应用的重要途径。一般而言，疏水性基层会注入选定的液体润滑剂以开发化学惰性的SLIPS。在此当前研究中，一种本质上亲水的（几分钟内可使串珠状水滴浸润且接触角约为20°）、多孔且较厚（超过200μm）的聚合物涂层，负载有易于发生化学反应的丙烯酸酯基团，产生了一种化学反应性SLIPS，其中合成的亲水性多孔界面中的残留丙烯酸酯基团使注入的润滑剂具有稳定性。这种化学反应性SLIPS能够在多孔聚合物涂层中存在润滑相（称为“原位”改性）和不存在润滑相（称为预改性）的情况下，通过1,4 -共轭加成反应与有机溶剂中含伯胺亲核试剂的溶液发生反应。这种胺反应性SLIPS进一步扩展到（1）研究不同化学改性对SLIPS性能的影响，以及（2）通过1,4 -共轭加成反应，利用含伯胺亲核试剂进行空间选择性“原位”后改性。此外，这种化学反应性SLIPS能够承受各种物理磨损，并能在复杂且苛刻的水相中长时间（至少10天）暴露，其中注入的润滑剂可保护残留的丙烯酸酯基团免受苛刻水相的影响。这样的原理对于直接从有机溶剂中进行水不溶性功能分子/聚合物的空间选择性共价固定肯定是有用的，这在各种应用和基础背景下可能会引起人们的兴趣。
