Porous Metal–Organic Framework@Polymer Beads for Iodine Capture and Recovery Using a Gas‐Sparged Column

Abstract

Iodine (I 2 ) capture and recovery is an important process in many industrial practices. Conventional materials for I 2 capture include Ag 0 -based aerogels and zeolites and C-based aerogels and powders, which suffer from expensive and/or inefficient recovery. Recently, metal-organic frameworks (MOFs) have shown potential as good adsorbents for I 2 capture with high capacity, fast uptake, and good recyclability. The powder form of MOFs, however, often makes them impractical in large-scale applications. Herein, a versatile method based on the phase inversion technique is presented to fabricate millimetersized spherical MOF@polymer composite beads, and the use of these beads for I 2 capture and recovery is demonstrated. Besides preserving the crystallinity and pore accessibility of the embedded MOFs in the polymeric matrix, the beads exhibit higher capacity and faster uptake rate for I 2 in both vapor and liquid phases compared to the bulk MOF powder. In order to showcase the applicability of these beads, a gas-sparged column is used as a proof-ofconcept device that can efficiently capture and recover more than 99% of I 2 from the feeding solution. The beads can be recycled and reused multiple times, which in combination with their easy handling and storage highlights their superiority compared to MOF powders in adsorption applications.

Incarceration of Iodine in a Pyrene‐Based Metal–Organic Framework

“…In recent years, metal–organic frameworks (MOFs), which are crystalline materials formed by linking metal ions or metal clusters with multi‐topic organic ligands, have emerged as promising adsorbents for I 2 capture due to their high porosity and chemical tunability . For example, our group has previously reported a high I 2 vapor uptake by HKUST‐1 and ZIF‐8, and their composites with polymers, reaching 538 mg g −1 HKUST‐1 at 75 °C . The Nenoff group and the Thallapally group have studied the adsorption of I 2 on HKUST‐1 and SBMOFs, respectively, in the presence of humidity .…”

“…HKUST-1 at 75 8C. [6] The Nenoff group and the Thallapally group have studied the adsorption of I 2 on HKUST-1a nd SBMOFs, respectively,i nt he presence of humidity. [7] However,t he degradation of these MOFs in water,a nd the leaching of I 2 from the I 2 -loaded MOFs when they are in contact with water and common organic solvents,g ive rise to considerable concerns regarding the potential of theseM OFs for I 2 capture.…”

“…Ther ate of adsorptiona t7 5 8Ci sf ivet imes greater than that of HKUST-1 crystalline powder,b ecause 1g of HKUST-1 adsorbs about 100 mg of I 2 after 5hours. [6] This also suggestst hat SION-8 has high affinity towards I 2 ,m ostp robably due to the strong interaction between the I 2 molecules and pyrene-decorated pore surfaceo fSION-8.B ased on our vdW-corrected DFT calculations, which have been previously shown to reliably quantify the host-guest interactions in MOF-based systems, [14] the computed I 2 binding energy is À73.2 kJ mol À1 ,w hich is comparable to those found in other charge-transfer MOF-I 2 complexes (MOFs with open metal sites). [15] More interestingly,w ashing the SION-8'I 2 powder with water or copiousa mounts of common organic solvents such as ethanol, toluene, and hexane gives rise to the releaseo fo nly 5.0 %o ft he capturedI 2 ( Figure S8, SupportingI nformation).…”

Hierarchically porous MOF/polymer composites via interfacial nanoassembly and emulsion polymerization

“…54 Many industrial applications require the processing of MOFs into task-specific configurations, including membranes, capsules, pellets and monoliths. 55 Since the MOF-stabilized emulsions prepared here are in a fluid state before polymerization, the resulting composites could be easily configured into different entities using shaped moulds as reactors where the polymerization happens 56 , as previously described by Wang and co-workers for magnetic MOF-based composite foams 27 . This concept was validated through filling various vials/moulds with emulsions followed by polymerization, as shown by the photographic images in Figure 1b and 1d.…”

Controllable Synthesis of Metal-Organic Framework/Polyethersulfone Composites

“…For the synthesis of MOF/PES composites, it is preferential to use PES as the support for the seed growth of the MOF layer [17] to grow MOF in situ in PES [18]. Although solidification of an MOF-PES mixed solution, which is a more efficient and direct strategy, has been used to synthesize MOF/PES composite beads [19,20] and a membrane [21][22][23], controllable synthesis of MOF/PES composites is highly necessary. Herein, three kinds of MOFs that have a stable structure and performance (ZIF-8, HKUST-1 and UiO-66) were selected as filling materials, and PES was used as a matrix to prepare MOF/PES composite materials.…”