Precise tuning of morphology and pore size of amine-functionalized MIL metal - organic frameworks using a directing agent

Abstract

Metal-organic framework (MOF) nanoparticles have attracted substantial interest for various applications that require a porous structure with a high surface area. To meet the demand for MOF nanoparticles, their structure needs to be systematically controllable using a simple method. In this paper, we report a novel synthetic approach for obtaining NH2-MIL-125(Ti) MOF nanoparticles using poly(ethylene glycol) diglycidyl ether (PEGDGE) as a directing agent. In contrast to traditional synthetic methods, using a directing agent in the synthesis can provide the desired external and internal structures for target applications. The PEGDGE can be used to tune the characteristics of the NH2-MIL-125(Ti) nanoparticles because it hinders coordination and acts as a substituent. The PEGDGE concentration can be adjusted to systematically decrease the particle size and develop a circular plate-like morphology by enlarging the pore size. Due to their tunable kinetic and thermodynamic characteristics, the NH2-MIL-125(Ti) nanoparticles can be employed in various applications.