Alginate Hydrogel: A Shapeable and Versatile Platform for in Situ Preparation of Metal–Organic Framework–Polymer Composites

Abstract

This work reports a novel in situ growth approach for incorporating metal-organic framework (MOF) materials into an alginate substrate, which overcomes the challenges of processing MOF particles into specially shaped structures for real industrial applications. The MOF-alginate composites are prepared through the post-treatment of a metal ion cross-linked alginate hydrogel with a MOF ligand solution. MOF particles are well distributed and embedded in and on the surface of the composites. The macroscopic shape of the composite can be designed by controlling the shape of the corresponding hydrogel; thus MOF-alginate beads, fibers, and membranes are obtained. In addition, four different MOF-alginate composites, including HKUST-1-, ZIF-8-, MIL-100(Fe)-, and ZIF-67-alginate, were successfully prepared using different metal ion cross-linked alginate hydrogels. The mechanism of formation is revealed, and the composite is demonstrated to be an effective absorbent for water purification.

Dual Physical Crosslinking Strategy to Construct Moldable Hydrogels with Ultrahigh Strength and Toughness

“…Figure a illustrates the tensile stress–strain curves of the Ch/PAAc hydrogels crosslinked with different metal cations. Compared to the PEC hydrogels, the strength of the DPC hydrogels enhanced to different extents because of the different degrees of affinity between the metal ions and polymers . The strength of DPC 0.10–0.25–0.5Cu 2+ could increase to 8.0 MPa while the others increased to 2.0 MPa.…”

Shaping of Flexible Metal‐Organic Frameworks: Combining Macroscopic Stability and Framework Flexibility

“…Extrusion and granulation often involve the use of additives as binding agents. The most commonly used binder is polyvinyl alcohol (PVA) but also biopolymers such as sucrose, alginate,, or chitosan were considered for MOF shaping. Other approaches make use of inorganic binders like bentonite, silica sol, or alumina that are traditionally employed for the production of shaped zeolites and mesoporous silicas .…”

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

“…As‐prepared MC‐ g ‐PMAANa monolith was used to adsorb heavy metal in different solvent conditions through its carboxylate groups, then MOFs were in situ grew on MC‐ g ‐PMAANa by the introduce of ligand solutions. In the case of ZIF‐67 growth, a practicable way of the MOF composite formation is that make it grow in methanol solution . Therefore, quantitative determination of Co(II) adsorption capacity was absent.…”

“…The incorporation of MOFs with polymer has been studied widely in recent years . Wickenheisser et al added MIL‐MOFs into prepolymer and synthesized various MIL‐MOF@Poly (NIPAM) monolithic composites .…”