Nanoporous Amphiphilic Hydrophobic–Oleophilic Metal–Organic Polyhedra Membranes for Oil–Water Separation

In this work, we have designed hydrolytically stable Cu24[5-(dec-9-en-1-yloxy) isophthalic acid]24 or CuMOP, where long deca-alkyl chain based 5-(dec-9-en-1-yloxy) isophthalic acid) coordinated with CuII paddlewheel centers. It is noteworthy to mention that the resultant mechanical flexible CuMOP-1 forms highly ordered nanoporous amphiphile structures, where there are long deca-alkyl evenly and symmetrically distributed nonpolar long alkyl chains and polar hydroxy groups. This assembly provides significant hydrophobicity (water advancing contact angle of 141°) and oleophilic nature (oil contact angle of 0°) due to lower surface energy (long alkyl chains). The unique properties like amphiphile structures, hydrophobic-oleophillic nature with improved structural moisture and mechanical stability for oil–water separation application. For the sake of real-time industrial application, we have prepared CuMOP-based thin and flexible membranes (denoted as CuMOP-1) using polymer PVDF on nonwoven substrates using a non-solvent-induced phase separation (NIPS) method. The resultant CuMOP-1 membrane shows remarkable oil–water separation application with signification separation efficiency >95% and a distribution coefficient >0.97 with significant permeation flux (5077–10 785 L m–2 h–1) and separation flux (∼4760 L m–2 h–1), because of its hydrophobic oleophilicity, hierarchical porous nature with improved structural and mechanical stability, because of its highly ordered amphiphilic nature. We believe that this work offers a perspective on the design and fabrication of various amphiphile structure based supramolecular metal–organic cavities, exhibiting superior oil–water separation applications.