Marta Estrader

The last decade has witnessed rapid progress in the development of soft microrobots for biomedical applications, largely powered by the incorporation of new materials in their design to address various challenges. Herein, a unique magnetic nanoparticle‐hydrogel composite designed for microrobot applications is introduced. This composite comprises iron platinum‐zinc ferrite nanoparticles whose magnetic properties are enhanced by magnetic exchange‐coupling behavior. The introduction of zinc ferrite further allows for grafting alkyne‐bearing ligands on the nanoparticles, enabling them to be covalently immobilized within the hydrogel framework via azide‐alkyne cycloaddition, thereby improving the composite's stability. Using a template‐assisted 3D fabrication technique, the feasibility of using this composite for soft microrobots is demonstrated. Hence, one can assume this straightforward procedure to be easily adapted to other material systems, facilitating the creation of more customized soft microrobots.

The last decade has witnessed rapid progress in the development of soft microrobots for biomedical applications, largely powered by the incorporation of new materials in their design to address various challenges. In this study, we introduce a unique magnetic nanoparticle-hydrogel composite designed for microrobot applications. This composite comprises iron platinum-zinc ferrite nanoparticles whose magnetic properties are enhanced by magnetic exchange-coupling behavior. The introduction of zinc ferrite further allows for grafting alkyne-bearing ligands on the nanoparticles, enabling them to be covalently immobilized within the hydrogel framework via azide-alkyne cycloaddition, thereby improving the composite’s stability. Using a template-assisted 3D fabrication technique, we demonstrated the feasibility of using this composite for soft microrobots. Hence, one could assume this straightforward procedure to be easily adapted to other material systems, facilitating the creation of more customized soft microrobots.

Magnetic nanoparticles offer versatile opportunities for anti-cancer therapy, stemming from a single metal element, iron, naturally processed by the human body. Applications range from magnetic hyperthermia to the emerging fields of photothermal therapy and ferroptosis induction.

Heterogeneous bi‐magnetic nanostructured systems have had a sustained interest during the last decades owing to their unique magnetic properties and the wide range of derived potential applications. However, elucidating the details of their magnetic properties can be rather complex. Here, a comprehensive study of Fe ₃ O ₄ /Mn ₃ O ₄ core/shell nanoparticles using polarized neutron powder diffraction, which allows disentangling the magnetic contributions of each of the components, is presented. The results show that while at low fields the Fe ₃ O ₄ and Mn ₃ O ₄ magnetic moments averaged over the unit cell are antiferromagnetically coupled, at high fields, they orient parallel to each other. This magnetic reorientation of the Mn ₃ O ₄ shell moments is associated with a gradual evolution with the applied field of the local magnetic susceptibility from anisotropic to isotropic. Additionally, the magnetic coherence length of the Fe ₃ O ₄ cores shows some unusual field dependence due to the competition between the antiferromagnetic interface interaction and the Zeeman energies. The results demonstrate the great potential of the quantitative analysis of polarized neutron powder diffraction for the study of complex multiphase magnetic materials.

Magnetic nanoparticles (NPs) are attractive both for their fundamental properties and for their potential in a variety of applications ranging from nanomedicine and biology to micro/nanoelectronics and catalysis. While these fields are dominated by the use of iron oxides, reduced metal NPs are of interest since they display high magnetization and adjustable anisotropy according to their size, shape and composition. The use of organometallic precursors makes it possible to adjust the size, shape (sphere, cube, rod, wire, urchin, …) and composition (alloys, core–shell, composition gradient, dumbbell, …) of the resulting NPs and hence their magnetic properties. We discuss here the synthesis of magnetic metal NPs from organometallic precursors carried out in Toulouse, as well as their associated properties and their potential in applications.

Magnetic nanoparticles (NPs) are attractive both for their fundamental properties and for their potential in a variety of applications ranging from nanomedicine and biology to micro/nanoelectronics and catalysis. While these fields are dominated by the use of iron oxides, reduced metal NPs are of interest since they display high magnetization and adjustable anisotropy according to their size, shape and composition. The use of organometallic precursors makes it possible to adjust the size, shape (sphere, cube, rod, wire, urchin, …) and composition (alloys, core–shell, composition gradient, dumbbell, …) of the resulting NPs and hence their magnetic properties. We discuss here the synthesis of magnetic metal NPs from organometallic precursors carried out in Toulouse, as well as their associated properties and their potential in applications.

We present here the design and preparation of several discrete coordination complexes exhibiting two Cu(II) ions separated by a dithienylcyclopentene as a photoswitchable spacer, proposed as models of molecular √SWAP quantum gates. These models use the two Cu(II) ions as realizations of qubits and the spacer as a light switch intended to trigger the gate by reversibly undergoing a ring closing isomerization. For this, a dicarboxylate species with a central diarylethene, H₂L1, has been used, together with bipyridine or phenantroline as capping ligands. Also, a new dinucleating ligand containing the photoactive moiety between two tridentate coordinating pockets, H₄L2, has been designed and prepared for the same purpose. The four complexes have been characterized by single‐crystal X‐ray diffraction. Three of them exhibit reversible photoswitching in solution.

The Fischer–Tropsch synthesis (FTS) is a structure‐sensitive exothermic reaction that enables catalytic transformation of syngas to high quality liquid fuels. Now, monolithic cobalt‐based heterogeneous catalysts were elaborated through a wet chemistry approach that allows control over nanocrystal shape and crystallographic phase, while at the same time enables heat management. Copper and nickel foams have been employed as supports for the epitaxial growth of hcp‐Co nanowires directly from a solution containing a coordination compound of cobalt and stabilizing ligands. The Co/Cu_foam catalyst was tested for Fischer–Tropsch synthesis in a fixed‐bed reactor, showing stability and significantly superior activity and selectivity towards C5+ compared to a Co/SiO₂‐Al₂O₃ reference catalyst under the same conditions.

The Fischer–Tropsch synthesis (FTS) is a structure‐sensitive exothermic reaction that enables catalytic transformation of syngas to high quality liquid fuels. Now, monolithic cobalt‐based heterogeneous catalysts were elaborated through a wet chemistry approach that allows control over nanocrystal shape and crystallographic phase, while at the same time enables heat management. Copper and nickel foams have been employed as supports for the epitaxial growth of hcp‐Co nanowires directly from a solution containing a coordination compound of cobalt and stabilizing ligands. The Co/Cu_foam catalyst was tested for Fischer–Tropsch synthesis in a fixed‐bed reactor, showing stability and significantly superior activity and selectivity towards C5+ compared to a Co/SiO₂‐Al₂O₃ reference catalyst under the same conditions.