(230o) Synthesis and Characterization of Polystyrene/ZIF-8 Core-Shell Particles By Solvothermal Method

Metal-organic frameworks (MOFs) have attracted much attention because of their tunable properties and various applications. MOFs are porous material consisting of metal ions (Zn, Cu, Co, etc.) or metal   clusters interconnected by organic molecules (ligands), showing organic-inorganic hybrid structures. Unlike other materials, MOFs are noted to show a good framework flexibility and shrinkage/expansion due to connection with guest molecules. Zeolitic imidazolate framework-8 (ZIF-8) is a sub class of MOFs, having an open channel structure composed of Zn ion and 2-methylimidazole. In this research, we investigated solvothermal synthesis of ZIF-8 particles, polystyrene/ZIF-8 core-shell particles, and hollow ZIF-8 particles.  The crystal sizes of ZIF-8 increased with solvothermal temperature from 50°C to 70°C. The polystyrene/ZIF-8 core-shell particles were synthesized by mixing polystyrene core particles and ZIF-8 precursor solution, followed by solvothermal treatment for 10 min at various temperatures (50°C, 60°C, 70°C). The ZIF-8 shell thickness increased with the temperature and the number of coating steps. To fabricate hollow ZIF-8 particles, polystyrene cores of the polystyrene/ZIF-8 core-shell particles were removed by washing them in N,N’-dimethylformamide (DMF). As synthesized ZIF-8 particles, polystyrene/ZIF-8 core-shell particle and hollow ZIF-8 particles were characterized by XRD, FE-SEM, TEM, BET, TGA, and particles size analysis. These ZIF-8 particles in core-shell and hollow forms can offer unique opportunities for gas separation, adsorption, gas storage, sensor and catalyst applications.