Facile preparation of UiO-66 /PAM monolithsviaCO₂-in-water HIPEs and their applications

Abstract

A novel clean method to synthesis a composite monolith was developed. Given its amphiphilic property, UiO-66 can emulsify water and CO 2 to format a high internal phase emulsion (HIPE) under certain conditions. These UiO-66-emulsified Pickering HIPEs can be used as templates to prepare interconnected macroporous MOF/polymer composite monoliths. The effects of UiO-66 amount, cross-linking agent concentration, and CO 2 -water ratio on UiO-66/PAM structures were investigated. Then, the as-synthesized MOF/PAM composites were characterized by TGA, XRD, SEM, and FT-IR analyses, as well as rheological and DMA measurements. The results indicated that the composites are interconnected with hierarchical pores, and the diameter of the voids is 10-50 mm.The directly prepared monoliths exhibited relatively high stresses at 82% strain and recovered their shape quickly. The adsorption capacity of the composites for methylene blue (MB) is 50 mg g À1 at a faster adsorption rate. The monoliths also exhibit underlying applications in edible oil-water separation.

Preparation of macroporous hybrid monoliths via iron‐based MOFs‐stabilized CO2‐in‐water HIPEs and use for β‐amylase immobilization

“…As the density of carbon dioxide increases, the average diameter of the void and the interconnected pore gradually decreases. This tendency has also been explained in the previous literature 23,24 …”

“…Figure 10 shows that Fe element is present in the composite and is evenly distributed, which certified that the MIL‐100(Fe) was uniformly compounding in monoliths. On the other hand, under the same monomer ratio, the N element content of this material is twice as high as the previously reported UiO‐66/PAM composite 24 . This result was ascribed to the added comonomer NIPAM, which increases the content of N element.…”

“…HKUST‐1 is another distinctive Cu‐MOF that can be used to emulsify CO 2 /W HIPEs to produce interconnected hydrophilic porous monoliths 23 . The supermacroporous UiO‐66/polyacrylamide monoliths were successfully synthesized via using UiO‐66 stabilized CO 2 ‐in‐water HIPE template method 24 . Iron‐based metal‐organic frameworks are less studied as a type of Pickering emulsifier in stabilizing high internal phase emulsions.…”

Synthesis of macroscopic monolithic metal–organic gels for ultra-fast destruction of chemical warfare agents

“…The application of Zr-MOF powders is greatly hampered, due to their inherent problems such as particle aggregation, poor processability and handling, mass transfer limitations, and signicant pressure drop in an adsorption bed. [11][12][13][14][15] To overcome the issues of Zr-MOF powders, many methods have been reported to construct Zr-MOF macroscale structures by either integrating Zr-MOFs into support materials such as bers, [16][17][18] polymeric monoliths 19,20 and foams, [21][22][23] or pelletizing Zr-MOF powders via mechanical compression or extrusion. [24][25][26] However, both strategies still have issues such as reduced adsorption capacities, due to the use of Zr-MOF as a secondary component, and pressure-induced losses of crystallinity and porosity.…”

Preparation of porous monoliths via CO2‐in‐water HIPEs template and the in situ growth of metal organic frameworks on it for multiple applications

“…Oh et al grew ZIFs on carboxymethylated filter paper . In our previous studies, polymer‐MOF composites have been prepared via polymerization of MOFs emulsified Pickering HIPEs …”