Mejora de las propiedades de Redes Metal-Orgánicas mediante la asociación de nano-especies activas

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Química Inorgánica, leída el 22-11-2021Metal-Organic Frameworks (MOFs) are crystalline solids composed by inorganic units (atoms, clusters, chains, …) linked by ionocovalent bonds to organic polydentate ligands (carboxylates, phosphonates, azolates, …) procuring a highly porous three-dimensional (3D) network. From the first reports in the early 90s, interest in MOFs, their chemistry and their applications have increased exponentially. Proving so, are the >13,300 publications registered only in 2020 (Web-of-Science: “Metal-Organic Frameworks”). MOFs outstand from other porous materials due to their hybrid versatile organic-inorganic composition (tunable ligands, presence of unsaturated metallic centers…), their structural richness (multiple topologies, isoreticular families…) and their exceptional porosity (with specific surface areas-SBET up to 8000 m2·g-1). As consequence, they have become an ideal candidate for relevant industrial and societal applications...Las Redes Metal-Orgánicas o MOFs (por sus siglas en inglés: Metal-Organic Frameworks) son sólidos cristalinos formados a partir de unidades inorgánicas (átomos, clúster, cadenas, …) y ligandos orgánicos polidentados (carboxilatos, fosfonatos, azolatos, ...) creando una red tridimensional (3D) con una importante porosidad. Desde las primeras publicaciones en los años 90, ha crecido exponencialmente el interés en los MOFs, su química y sus aplicaciones. Muestra de ello son las más de 13300 publicaciones registradas tan sólo en 2020 (Web-of-Science: “Metal-Organic Frameworks”). Los MOFs destacan frente a otros materiales porosos debido a su composición híbrida versátil (ligando fácilmente modificable, presencia de centros metálicos insaturados), su riqueza estructural (multitud de topologías, familias isoreticulares) y su porosidad excepcional (áreas superficiales-SBET de hasta 8000 m2·g-1), convirtiéndolos en candidatos prometedores en diversas aplicaciones de relevancia social e industrial...Fac. de Ciencias QuímicasTRUEunpu

Phase-Selective Microwave Assisted Synthesis of Iron(III) Aminoterephthalate MOFs

Iron(III) aminoterephthalate Metal-Organic Frameworks (Fe-BDC-NH2 MOFs) have been demonstrated to show potential for relevant industrial and societal applications (i.e., catalysis, drug delivery, gas sorption). Nevertheless, further analysis is required in order to achieve their commercial production. In this work, a systematic synthetic strategy has been followed, carrying out microwave (MW) assisted hydro/solvothermal reactions to rapidly evaluate the influence of different reaction parameters (e.g., time, temperature, concentration, reaction media) on the formation of the benchmarked MIL-101-NH2, MIL-88B-NH2, MIL-53-NH2 and MIL-68-NH2 solids. Characterization of the obtained solids by powder X-ray diffraction, dynamic light scattering and transmission electron microscopy allowed us to identify trends to the contribution of the evaluated parameters, such as the relevance of the concentration of precursors and the impact of the reaction medium on phase crystallization. Furthermore, we presented here for the first time the MW assisted synthesis of MIL-53-NH2 in water. In addition, pure MIL-101-NH2 was also produced in water while MIL-88-NH2 was the predominant phase obtained in ethanol. Pure phases were produced with high space-time yields, unveiling the potential of MW synthesis for MOF industrialization

Aqueous Stable Gold Nanostar/ZIF‐8 Nanocomposites for Light‐Triggered Release of Active Cargo Inside Living Cells

This is the peer reviewed version of the following article: C. Carrillo-Carrión, R. Martínez, M. F. Navarro Poupard, B. Pelaz, E. Polo, A. Arenas-Vivo, A. Olgiati, P. Taboada, M. G. Soliman, Ú. Catalán, S. Fernández-Castillejo, R. Solà, W. J. Parak, P. Horcajada, R. A. Alvarez-Puebla, P. del Pino, Angew. Chem. Int. Ed. 2019, 58, 7078, which has been published in final form at https:// doi.org/10.1002/anie.201902817. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsA plasmonic core–shell gold nanostar/zeolitic‐imidazolate‐framework‐8 (ZIF‐8) nanocomposite was developed for the thermoplasmonic‐driven release of encapsulated active molecules inside living cells. The nanocomposites were loaded, as a proof of concept, with bisbenzimide molecules as functional cargo and wrapped with an amphiphilic polymer that prevents ZIF‐8 degradation and bisbenzimide leaking in aqueous media or inside living cells. The demonstrated molecule‐release mechanism relies on the use of near‐IR light coupled to the plasmonic absorption of the core gold nanostars, which creates local temperature gradients and thus, bisbenzimide thermodiffusion. Confocal microscopy and surface‐enhanced Raman spectroscopy (SERS) were used to demonstrate bisbenzimide loading/leaking and near‐IR‐triggered cargo release inside cells, thereby leading to DNA stainingThis work has received financial support from the MINECO‐Spain (MAT2016‐80266‐R, MAT2015‐74381‐JIN, CTQ2017‐88648R, ENE2016‐79608‐C2‐1‐R, CTQ2017‐89588‐R, RYC‐2014‐15039, RYC‐2014‐16962), the Xunta de Galicia, Centro singular de investigación de Galicia accreditation 2016–2019 (ED431G/09), the Agrupación Estratégica de Materiales Action (ED431E 2018/08), the Generalitat de Cataluña (2017SGR522, 2017SGR883, SLT002/16/00239), the URV (2017PFR‐URV‐B2‐02), the German Research Society (DFG PA 794‐21‐1), and the European Union (European Regional Development Fund—ERDF, H2020‐MSCA‐IF‐2016, project 749667). M.F.N.P acknowledges the CONACYT PhD fellowship programS

Ultrafast reproducible synthesis of a Ag-nanocluster@MOF composite and its superior visible-photocatalytic activity in batch and in continuous flow

International audienceThe (photo)catalytic properties of metal–organic frameworks (MOFs) can be enhanced by post-synthetic inclusion of metallic species in their porosity. Due to their extraordinarily high surface area and well defined porous structure, MOFs can be used for the stabilization of metal nanoparticles with adjustable size within their porosity. Originally, we present here an optimized ultrafast photoreduction protocol for the in situ synthesis of tiny and monodisperse silver nanoclusters (AgNCs) homogeneously supported on a photoactive porous titanium carboxylate MIL-125-NH2 MOF. The strong metal–framework interaction between –NH2 and Ag atoms influences the AgNC growth, leading to the surfactant-free efficient catalyst AgNC@MIL-125-NH2 with improved visible light absorption. The potential use of AgNC@MIL-125-NH2 was further tested in challenging applications: (i) the photodegradation of the emerging organic contaminants (EOCs) methylene blue (MB-dye) and sulfamethazine (SMT-antibiotic) in water treatment, and (ii) the catalytic hydrogenation of p-nitroaniline (4-NA) to p-phenylenediamine (PPD) with industrial interest. It is noteworthy that compared with the pristine MIL-125-NH2, the composite presents an improved catalytic activity and stability, being able to photodegrade 92% of MB in 60 min and 96% of SMT in 30 min, and transform 100% of 4-NA to PPD in 30 min. Aside from these very good results, this study describes for the first time the use of a MOF in a visible light continuous flow reactor for wastewater treatment. With only 10 mg of AgNC@MIL-125-NH2, high SMT removal efficiency over 70% is maintained after >2 h under water flow conditions found in real wastewater treatment plants, signaling a future real application of MOFs in water remediation

Fluorescence labeling of high density polyethylene for identification and separation of selected containers in plastics waste streams. Comparison of thermal and photochemical stability of different fluorescent tracers

In recent years, a great effort has been devoted to the development of new automated identification and sorting methods for post-consumer plastics in the waste streams that reach the recycling processes, as the final properties of the recycled materials largely depend on the purity of the plastic residue. This work explores the use of fluorescence spectroscopy as a complementary technique to address the limitations of the current technologies. Specifically, the use of fluorescent markers for the removing, for technical or safety related issues, of selected high density polyethylene containers from the waste stream has been studied. The results indicate that identification by extrinsic fluorescence can be easily achieved even with small proportion of markers (10−3 wt%) without significant change of the polymer structure. The effect of thermal, hygrothermal and photochemical degradation on the fluorescence emission has been analyzed. Although the signal intensity decreases during the accelerated degradation, distinguishable fluorescent emission was recorded even after sample exposure to aggressive conditions, thus enabling the correct identification of the marked plastics

Antiadherent AgBDC Metal–Organic Framework Coating for <i>Escherichia coli</i> Biofilm Inhibition

Surface microbial colonization and its potential biofilm formation are currently a major unsolved problem, causing almost 75% of human infectious diseases. Pathogenic biofilms are capable of surviving high antibiotic doses, resulting in inefficient treatments and, subsequently, raised infection prevalence rates. Antibacterial coatings have become a promising strategy against the biofilm formation in biomedical devices due to their biocidal activity without compromising the bulk material. Here, we propose for the first time a silver-based metal–organic framework (MOF; here denoted AgBDC) showing original antifouling properties able to suppress not only the initial bacterial adhesion, but also the potential surface contamination. Firstly, the AgBDC stability (colloidal, structural and chemical) was confirmed under bacteria culture conditions by using agar diffusion and colony counting assays, evidencing its biocide effect against the challenging E. coli, one of the main representative indicators of Gram-negative resistance bacteria. Then, this material was shaped as homogeneous spin-coated AgBDC thin film, investigating its antifouling and biocide features using a combination of complementary procedures such as colony counting, optical density or confocal scanning microscopy, which allowed to visualize for the first time the biofilm impact generated by MOFs via a specific fluorochrome, calcofluor