RESUMEN
The production of MOFs at large scale in a sustainable way is key if these materials are to be exploited for their promised widespread application. Much of the published literature has focused on demonstrations of preparation routes using difficult or expensive methodologies to scale. One such MOF is nano-zeolitic imidazolate framework-8 (ZIF-8) - a material of interest for a range of possible applications. Work presented here shows how the synthesis of ZIF-8 can be tracked by a range of methods including X-ray diffraction, thermo gravimetric analysis and inelastic neutron scattering - which offer the prospect of in-line monitoring of the synthesis reaction. Herein we disclose how the production of nano-ZIF-8 can be conducted at scale using the intermediate phase ZIF-L. By understanding the economics and demonstrating the production of 1 kg of nano-ZIF-8 at pilot scale we have shown how this once difficult to make material can be produced to specification in a scalable and cost-efficient fashion.
RESUMEN
Affordable and readily available microelectronics are becoming prevalent in teaching laboratories however these useful and economic tools are not used widely in either academia or industry. Herein we report how a metal organic framework (MOF) synthetic route can be optimized using an in situ monitoring apparatus designed in-house on open source hardware for under $100. We demonstrate that the MOF can be produced at atmospheric pressure, an improvement over previous reports, but also with a reduction in reaction time of 93%. This improvement in reaction time was predicted after a single experiment using the monitoring kit showing how efficiencies in the lab can be gained with very little experimental and monetary overhead while minimising the resources used.
RESUMEN
There is an increasing amount of interest in metal-organic frameworks (MOFs) for a variety of applications, from gas sensing and separations to electronics and catalysis. However, the mechanisms by which they crystallize remain poorly understood. Herein, an important new insight into MOF formation is reported. It is shown that, prior to network assembly, crystallization intermediates in the canonical ZIF-8 system exist in a dynamic pre-equilibrium, which depends on the reactant concentrations and the progress of reaction. Concentration can, therefore, be used as a synthetic handle to directly control particle size, with potential implications for industrial scale-up and gas sorption applications. These findings enable the rationalization of apparent contradictions between previous studies of ZIF-8 and opens up new opportunities for the control of crystallization in network solids more generally.
