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

[Display omitted] •We propose a new synthetic route to produce NH2-MIL-125(Ti) using a directing agent.•We used poly(ethylene glycol) diglycidyl ether (PEGDGE) as the directing agent.•The external and internal structures of MOFs can be simply tuned by adding PEGDGE•The morphology tuning of MOFs enable optimal diffusion and adsorption of molecules. 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.