The lamellar MOFs@polymer networks hybrids fabricated in reversed microemulsion for efficient CO₂ capture

Abstract

ZIF-8@polymer networks hybrids (ZIF-8@PNs), consisting of the flexible CO 2 responsive polymer and rigid ZIF-8 crystals, were fabricated using DMAPMA as the monomer and BIS as the cross-linker by the reversed microemulsion polymerization, and characterized by the powder XRD, SEM, TEM, DLS, FT-IR, and TGA. Monomers and cross-linkers were initiated by AIBN to form polymer networks which coated ZIF-8 crystals. The shape of ZIF-8@PNs was modulated by the micelles of surfactant in the reversed microemulsion. In particular, the lamellar ZIF-8@PNs hybrids with the regular thickness of 50-70 nm in which ZIF-8 crystals were wrapped by the flexible polymer networks and still retained the crystal skeleton, were fabricated at the high concentration of surfactant in the reversed microemulsion. Additionally, the adsorption capacity of ZIF-8@PNs hybrids for CO 2 has been evaluated. Under the higher initial pressure at the lower temperature, the adsorption of ZIF-8@PNs for CO 2 was higher than that of the pure ZIF-8, and was an increasing of 180%.

Chitosan/ZIF‐8 Composite Beads Fabricated by In Situ Growth of MOFs Crystals on Chitosan Beads for CO2 Adsorption

“…[57] In our previous work, ZIF-8@PNs, consisting of the flexible CO 2 responsive poly [N-(3-(dimethylamino) propyl) methacrylamide] (PDMAPMA) networks and the ZIF-8 crystals, showed higher CO 2 adsorption than the pure ZIF-8 crystals, and its CO 2 adsorption was an increasing of 180 %. [58] In the similar initial environment, the adsorption capacity of ZIF-8@PNs for CO 2 was lower than that of CBsZx. The adsorption capacity of chitosan/ ZIF-8 composites being prepared by one-pot method for CO 2 was 0.56 mmol/g.…”

Heterogeneous nucleation and growth of MOF crystals on polymer substrate to fabricate chitosan/ZIF-8 hydrogels for efficient capture of CO2

“…Although tuning the morphology of MOFs is operative in progressing their performance, it does not improve the poor performance caused by the inherent defects of MOFs such as their high brittleness, poor stability in water, and difficulty of recycling them. 14 In contrast to MOFs, flexible polymers tend to be very hydrophilic and recyclable. 15 The stark differences between the nature of the MOFs and polymers have motivated efforts to hybridise crystalline MOFs and flexible polymers to produce composites that retain the desired properties of these materials.…”

Modulated Growth of MOFs to Fabricate ZIF-8@Chitosan/Polyvinylpyrrolidone Hydrogels with Improved Adsorption Capacity for CO2

“…ZIF-8@PNs adsorbed CO 2 more effectively than the pure ZIF-8, and the adsorption was increased by 180% under higher beginning pressures at lower temperatures. 30 Meanwhile, CS/ MOF composite gels were prepared by the in situ growth of ZIF-8. ZIF-8 crystals with spherical, cubic, tetrahedral, and cuboid shapes were formed on CS gels, and adsorptions of CS/ ZIF-8 gels for CO 2 were higher than that of pure ZIF-8 crystals and CS gels.…”

“…Chitosan (CS), a biodegradable, biocompatible, and nontoxic biopolymer, has many primary amine groups (–NH 2 ) and is considered potentially CO 2 -responsive. − In our previous paper, MOFs/polymer network composite hybrids ZIF-8@PNs consisting of flexible polymer networks and rigid ZIF-8 crystals were prepared by reverse microemulsion polymerization. ZIF-8@PNs adsorbed CO 2 more effectively than the pure ZIF-8, and the adsorption was increased by 180% under higher beginning pressures at lower temperatures . Meanwhile, CS/MOF composite gels were prepared by the in situ growth of ZIF-8.…”