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

Abstract

The current study reports the utilization of MIL‐100(Fe) as Pickering emulsifiers to stabilize CO2‐in‐water high internal phase emulsions, thereby synthesizing interconnected macroporous hybrid monoliths with adjustable pore sizes. During such a green synthesis procedure, the influences of Fe‐MOF type and content, carbon dioxide density, and the amount of crosslinker have been explored respectively. The as‐synthesized MOF‐containing poly(HIPE)s were characterized by FT‐IR, XRD, SEM, CLSM, and TGA. The morphology of the monoliths was mainly observed by EDS‐mapping and SEM, which showed that Fe‐MOFs were uniformly distributed into the monolithic matrix and the void sizes and interconnected pore sizes were 20 to 150 μm and 5 to 50 μm, respectively. Furthermore, the MIL‐100(Fe)‐containing monoliths exhibited an excellent elasticity and can quickly return to their original state when reaching up to 90% compressive strain without failing. To evaluate the adsorptive properties of the composite monoliths, the immobilization of β‐amylase on the obtained monoliths was studied. The results of immobilized enzymes showed that the highest protein adsorption rate can reach 55% and the immobilization efficiency can reach 89%. Since our synthetic route is clean and controllable, biocompatible monoliths with good elasticity and toughness were prepared, which presents a viable strategy to produce hybrid monoliths for bio‐medical applications.

Controlling polyHIPE Surface Properties by Tuning the Hydrophobicity of MOF Particles Stabilizing a Pickering Emulsion

“…The shaping of the PH-UiO-66­(F4) material results in a decrease of the specific surface area to 100 m 2 g –1 , and the micropore volume drops close to zero. The shaping of crystalline powders therefore drastically hinders their accessibility, which is a consequent drawback encountered in monoliths prepared from Pickering emulsions. ,, Then, adsorbing PFOA molecules on the surface of the MOF particles leads to an increase of the final specific surface area, particularly due a higher micropore volume (Figure b). Indeed, the MOF particles are more and more hydrophobic with the higher amount of adsorbed PFOA, and their adsorption at the organic–aqueous phase interface is modified.…”

“…Indeed, a part of the MOF surface remains trapped in the wall of the polymeric support. This leads to a significant reduction of the MOF microporosity and consequently to a strong decrease of their efficiency. ,− …”

Synthesis of CO2-philic/hydrophilic surfactant with brush structure and its application in preparing monolithic material

“…The structure of monolithic materials can re ect the original state of HIPEs [28] . Using the above method, many types of porous materials were synthesized, such as MOFs-stabilized porous materials [29][30][31] , poly(ionic liquid)-based porous materials [32] , etc. These materials have a high speci c surface area, and are widely applied in many elds, such as CO 2 capture, pollutant removal, biological tissue engineering, etc [33][34][35][36] .…”

β‐Cyclodextrin‐based macroporous monoliths: One‐pot oil‐in‐oil emulsion templating and adsorption

“…The interest in macroporous emulsion‐templated polymer systems for a variety of adsorption applications has increased significantly in recent years. These applications, inspired by the versatility that emulsion templating has to offer, both in the nature of the polymer walls and in the functionality of the polymer surface, include systems for the adsorption of cationic organics, 34,48–55 herbicides, 56 viruses, 57 metal ions, 58–66 phenolics, 67 and proteins 68 …”