Spherical Magnetic Fe-Alginate Microgels Fabricated by Droplet-Microfluidics Combining with an External Crosslinking Approach and the Study of Their pH Dependent Fe³⁺ Release Behaviors

Due to the rapid development and potential applications of iron(III)-alginate (Fe-Alg) microgels in biomedical as well as environmental engineering, this study explores the preparation and characterization of spherical Fe-Alg microgels using droplet microfluidics combined with an external ionic crosslinking method. This study focused on the role of Fe³⁺ and examined its effects on the physical/chemical properties of microgels under different ionic conditions and reduced or oxidized states. The pH-dependent release behavior of Fe³⁺ from these microgels demonstrates their potential biomedical and environmental applications. Furthermore, the microgels can exhibit magnetism simply by utilizing in situ oxidation, which can be further used for targeted drug delivery and magnetic separation technologies.