Preparation and antibacterial performance of a conjugated microporous polymer nanosheet-based membrane†

The engineering of two-dimensional (2D) nanomaterials and membranes with antibacterial traits has recently gained tremendous attention for alleviating antibiotic abuse and for water sanitization. Here, for the first time, without any substrate support, a macroscopic and thickness-controllable conjugated microporous polymer (CMP) nanosheet-based membrane (named 2DCMP) was developed for water sterilization, using 1,3,5-triethynylbenzene and trichloroisocyanuric acid as monomers through a liquid–liquid interfacial method at room temperature. The resulting 2DCMP possessed a lamellar topology with folded edges and a smooth surface just like “Chinese silk”. Its Young's modulus was measured to be 4–5 GPa. Moreover, owing to the construction of nanosheets and the introduction of antibacterial groups into the polymeric skeleton, the resulting 2DCMP exhibited antibacterial activity with more than 90% bacterial cell viability loss in water at 1000 μg mL⁻¹ after 0.5 h of exposure, superior to powdery CMP materials. Moreover, the hydrophilic and free-standing 2DCMP (∅ 20 mm × 20 μm) assembled from CMP nanosheets also displayed a rejection of 94% for a bacteria-containing solution (with a concentration of 10³ CFU mL⁻¹) with a pure water permeance of 104 L m⁻² h⁻¹ bar⁻¹. Our work may promote a highly-effective and scalable fabrication strategy for 2D CMP nanomaterials with antibacterial activity for water sterilization, biofouling, sanitary purposes and environmental remediation.