Supercritical CO2 for the synthesis of nanometric ZIF-8 and loading with hyperbranched aminopolymers. Applications in CO2 capture

Abstract

ZIF-8 nanometric particles are prepared via an environmentally friendly supercritical method aimed to minimize the environmental impact of current developed technologies for the synthesis of metal organic frameworks. In this synthetic process, CO2 and ZIF-8 precursors are exclusively employed, avoiding the use of organic liquids, difficult to recover additives or large amounts of expensive ligand excess. The straight and high yield precipitation of empty-pore ZIF-8 nanopowder with tunable morphology was achieved. The powder was fully characerized in regard to the composition, structure, stability, morphology and textural properties. This work also focuses in the development of an eco-efficient method for the in situ polymerization of ethyleneimine inside the synthetized ZIF-8 pores, by using supercritical CO2 as a solvent, reaction medium and catalyst for the aziridine ring-opening. The use of the prepared materials in CO2 capture is assessed by analyzing CO2 adsorption isotherms.