Synergistic Chemical Synthesis and Self-Assembly Lead to Three-Dimensional b-Oriented MFI Superstructures with Selective Adsorption and Luminescence Properties

Chemistry. 2018 Feb 26;24(12):2980-2986. doi: 10.1002/chem.201705329. Epub 2018 Jan 29.

Abstract

Higher-order organization of inorganic nanoparticles with hierarchical architectures and tailored functionality is crucial in the nanofabrication of advanced materials. Here we demonstrate that three-dimensional b-oriented MFI superstructures can be organized by synergistic chemical synthesis and self-assembly. The organization is accomplished by vapor treatment of tetrapropylammonium hydroxide (TPAOH)-coated inorganic/bacterial cellulose scaffolds. TPA+ acts to direct nucleation and to mediate crystal morphology leading to oriented assembly of MFI crystals along crystallographic b-axis, whereas bacterial cellulose holds the oriented assembly together forming three-dimensional superstructures with macroporosity. Self-supporting monoliths of the macroporous MFI show outstanding selective adsorption for para-xylene and high adsorption capacity for volatile organic compounds. Incorporating luminescent molecules imparts the macroporous monoliths the new property of adsorption tunable luminescence that may act as an optical sensor indicating the level of adsorption. The current work opens a novel space for rational organization of hierarchical materials with tailored architectures and multifunctionality.

Keywords: MFI superstructures; selective adsorption; self-assembly; self-supporting monolith; volatile organic compounds.