Assembly of a Metal-Organic Framework into 3 D Hierarchical Porous Monoliths Using a Pickering High Internal Phase Emulsion Template.

3D Hierarchical porous metal-organic framework (MOF) monoliths are prepared by using Pickering high internal phase emulsion (HIPE) template. Pickering HIPEs were stabilized solely by UiO-66 MOF particles with internal phase up to 90 % of the volume. The effects of internal phase type and volume, as well as MOF particle concentration on the stability of resulting Pickering HIPEs were investigated. Furthermore, by adding small amount of polyvinyl alcohol (PVA) as binder or polymerization in the continuous aqueous phase, followed by freeze-drying, two types of MOF-based 3D hierarchical porous monoliths with ultralow density (as low as 12 mg cm(-3) ) were successfully prepared. This Pickering HIPE template approach provides a facile and practical way for assembling of MOFs into complex structures.