Metal-organic frameworks (MOFs) are an emergent class of porous crystalline materials composed of metal ions or nodes and organic linkers. Their high surface area and tunable structures make them candidates in applications ranging from drug delivery and catalysis to gas sensing and storage. However, lack of stimuli responsiveness and macroscopic ordering of MOFs pose issues in integrating them into functional devices or sensors. To mediate these issues, MOF hybrid materials are of special interest. One such class of hybrids are MOF hydrogel composites which utilize the metal nodes of a MOF to crosslink hydrophilic polymer chains and form a gel. Previous work suggests a wide variety of functionalities are possible for these gels, but no work has previously been done on stimuli responsiveness or incorporation of Zr-based MOFs into the gel systems. In this study, we synthesize a Zr-trimesic acid (BTC)-alginate (Alg) hydrogel composite and confirm incorporation of both the zirconia node and linker into the gel. The Zr-BTC-Alg gel shows increased loading capacity compared to both the corresponding hydrogel and MOF alone. Additionally, stimuli response testing of methylene blue loaded Zr-BTC-Alg gels indicate selective release or extended encapsulation in stimuli that cause gel swelling or shrinking, respectively. Methylene blue encapsulation trials suggest enhanced stability in acid for the composite gels and display greater distinctions in material response to environments of varying pH. Further testing of stimuli response and gel state characterization are needed to evaluate the complete functionality of the hybrid materials for environmental sensors or devices.

Synthesis and characterization of metal-organic framework hydrogel composites

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.