Surfactant-Free ZIF-8 Decorated and Open Porous Pickering Polymerized High Internal Phase Emulsion

Abstract

Metal-organic frameworks (MOFs) represent an emerging class of porous materials with significant potential for various applications. However, their utilization in powder form poses challenges for industrial-scale applications. Consequently, there is active research in developing supporting materials for MOFs. This research article explores the effectiveness of loading MOFs, specifically ZIF-8, onto polymerized high internal phase emulsions (PolyHIPEs). ZIF-8 was used as a sole emulsion stabilizer, as well as in combination with polymeric colloidal particles and surfactant as co-stabilizers of the emulsion. The findings indicate that when ZIF-8 is used as the sole emulsion stabilizer, it leads to well-surface-decorated but closed pore PolyHIPEs. Combining ZIF-8 with IBOA microparticles as emulsion stabilizers results in similarly well-decorated but interconnected porous structures. While the commonly used apporach using MOFs (ZIF-8) together with a surfactant (Hypermer B246) produced an interconnected porous structure, the pores become poorly decorated with ZIF-8. This is attributed to an antagonistic effect between Hypermer B246 and ZIF-8. The study employed morphological investigations, SEM micrographs, thermogravimetric analysis, and energy-dispersive X-ray analysis to evaluate the ZIF-8 loading efficacy in PolyHIPEs.