(748b) Functionalized High Aspect Ratio PCN-222 Nanoparticles for Tunable Reverse Osmosis Performance

Nanorods of PCN-222, a large-pore, zirconium-based porphyrinic metal-organic framework (MOF), have been prepared through coordination modulation for incorporation into reverse osmosis thin film nanocomposite (TFN) membranes. Myristic acid can be loaded into the MOF pores via solvent-assisted ligand incorporation to alter channel dimensions and pore size distribution. TFNs are a class of materials that rely on functional nanoparticles to provide improvements over traditional thin film composite (TFC) reverse osmosis membranes. TFN membranes containing PCN-222 nanoparticles modified with varying levels of myristic acid were fabricated via dispersion of nanoparticles in the aqueous phase of an interfacial polymerization, and the resulting flux and rejection capabilities of each membrane were evaluated. The membranes were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle goniometry. The best result was observed at 0.01 wt% PCN-222 loading with a 10:1 myristic acid to TCPP linker modification, where membrane flux increased by 190% and salt rejection decreased marginally compared to the plain polyamide control membrane (96.0 ± 2.4% vs. 97.5 ± 0.3%). This flux increase is attributed to water transport through the nanoparticle pore structure, and thus further studies are necessary to determine the optimal PCN-222 loading and pore size modifications, leading to the fabrication of TFN membranes with tunable properties.