(447a) High Aspect Ratio ZIF Nanoplates for Mixed Matrix Membrane

Metal-organic frameworks (MOFs) with high aspect ratios have the potential to enhance gas separation performance when incorporated into mixed matrix membranes (MMMs). We present a study where we synthesized high aspect ratio zeolitic imidazolate framework-8 (ZIF-8) nanoplates using a direct template conversion method, employing high aspect ratio layered Zn hydroxide sheets as sacrificial precursors. These nanoplates were shear-aligned in a 6FDA-DAM polymer matrix, resulting in significant improvements in propylene/propane separation performance. We also studied the effect of MOF filler shape on the mechanical, thermal, and gas separation properties of the resulting MMMs. The high aspect ratio NZIF-8/PI membrane showed improved mechanical properties and long-term thermal stability at 300°C compared to membranes with isotropic fillers. Furthermore, high aspect ratio fillers enabled a substantial enhancement in hydrogen separation performance, exhibiting hydrogen permeability of around 1800 Barrer and a hydrogen/propane selectivity of 260 at 20 wt% ZIF-8 nanoplate loading. These findings highlight the potential of high-aspect ratio MOFs for improving gas separation performance in MMMs, particularly for hydrogen extraction in the propane dehydrogenation process. In addition to these topics, the performance enhancement of composite membranes by surface modification of ZIF nanoplates and polymers will be covered. The potential for large area fabrication of composite membranes will also be discussed.