Colloidal Stability and Solubility of Metal–Organic Framework Particles

• DOI: 10.1021/acs.chemmater.3c03191
• Publication Date: 2024-04-11T15:25:30Z
• Authors: Michael A. LeRoy; Anton S. Perera; Shasanka Lamichhane; Ashley N. Mapile; Faiqa Khaliq; Kentaro Kadota; Xianghui Zhang; Su Ha; Racheal Fisher; Di Wu; Chad Risko; Carl K. Brozek
• Keywords: Hildebrand solubility parameter; Chemical Stability

Chemical separation membranes, drug delivery agents, and other nascent applications of metal–organic frameworks (MOFs) benefit from preparing MOFs as nanoparticles (nanoMOFs) by controlling their particle surfaces. Despite the lack deliberately added surface ligands, or surfactants, common examples nanoMOFs exhibit multiweek colloidal stability in a range polar solvents. Whereas nanocrystal general arises combination electrostatic repulsion, steric hindrance between species, favorable interactions with solvent, present unusual interior exterior surfaces for these to transpire. Here, we demonstrate that suspend only solvents dissolve constituent MOF linkers. Moreover, maximum "solubility" nanoMOFs, i.e., concentration saturated suspensions, correlates solubility linkers same solvent. Calorimetry measurements indicate nanoMOF immersion enthalpies resemble solvation linkers, suggesting solvent–linker dictate stability. As proof-of-concept, whereas generally solvents, achieve suspensions toluene identifying soluble Furthermore, atomistic molecular dynamics simulations reveal best at dissolving are those pack densely into pores interact These results provide predictive tool achieving highlight uniqueness defining "surface", where access both