Complete Characterization of α-Hopeite Microparticles: An Ideal Nucleation Seed for Metal Organic Frameworks

This work reports on the structural and microstructural characterization of a new class of α-hopeite microparticles, which has recently been discovered as ideal seeding agents for the formation and functionalization of metal organic framework (MOF-5) crystals. The particles have been named desert rose microparticles (DRMs), as their morphology closely resembles that of the famous gypsum and Barite mineral. The DRMs form directly inside the MOF-5 precursor solution when a block copolymer surfactant, Pluronic F-127, is added in specific amounts. The particles formation is remarkably fast, and particles are observed to form within the first minute of reaction. The DRMs formation and growth has been monitored along a 3 h synthesis, until the first nuclei of MOF-5 start to appear on their surface. Electron microscopy, energy dispersive analysis, electron diffraction, FTIR, FT-Raman, and BET give an all-around description of the chemical and morphological features that give the DRMs their remarkable MOF-seeding capacity.