Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros

Banco de datos
Tipo de estudio
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Angew Chem Int Ed Engl ; 62(4): e202215600, 2023 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-36446737

RESUMEN

Zinc metal battery (ZMB) is promising as the next generation of energy storage system, but challenges relating to dendrites and corrosion of the zinc anode are restricting its practical application. Here, to stabilize Zn anode, we report a controlled electrolytic method for a monolithic solid-electrolyte interphase (SEI) via a high dipole moment solvent dimethyl methylphosphonate (DMMP). The DMMP-based electrolytes can generate a homogeneous and robust phosphate SEI (Zn3 (PO4 )2 and ZnP2 O6 ). Benefiting from the protecting impact of this in situ monolithic SEI, the zinc electrode exhibits long-term cycling of 4700 h and a high Coulombic efficiency 99.89 % in Zn|Zn and Zn|Cu cell, respectively. The full V2 O5 |Zn battery with DMMP-H2 O hybrid electrolyte exhibits a high capacity retention of 82.2 % following 4000 cycles under 5 A g-1 . The first success in constructing the monolithic phosphate SEI will open a new avenue in electrolyte design for highly reversible and stable Zn metal anodes.

2.
Soft Matter ; 18(28): 5194-5203, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35195649

RESUMEN

Improving the electrical performance of macroradical epoxy thermosets to surpass the semiconductor threshold requires a comprehensive understanding of the electrical charge transport mechanisms and characteristics. In this study, we investigate the electrical properties of a non-conjugated radical thermoset in a rigid, three-dimensional (3D) motif cured under an external magnetic field. The outcomes of the four-angle analysis of the synchrotron IRM beamline provide for the first time quantitative insights into the molecular orientation at the atomic-scale level. These insights, in turn, were utilized to apply Quantum Computational modeling theories and Monte Carlo simulation to study the effect of the magnetic field-induced molecular alignment on tuning electrical charge transport characteristics. The results explored the impact of radical density on forming percolation networks, showing a robust protocol for designing polymers with high electrical/thermal conductivity.

3.
Adv Mater ; : e2401454, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38685794

RESUMEN

Single atom catalysts (SACs) are atomic-level-engineered materials with high intrinsic activity. Catalytic centers of SACs are typically the transition metal (TM)-nonmetal coordination sites, while the functions of coexisting non-TM-bonded functionalities are usually overlooked in catalysis. Herein, the scalable preparation of carbon-supported cobalt-anchored SACs (CoCN) with controlled Co─N sites and free functional N species is reported. The role of metal- and nonmetal-bonded functionalities in the SACs for peroxymonosulfate (PMS)-driven Fenton-like reactions is first systematically studied, revealing their contribution to performance improvement and pathway steering. Experiments and computations demonstrate that the Co─N3C coordination plays a vital role in the formation of a surface-confined PMS* complex to trigger the electron transfer pathway and promote kinetics because of the optimized electronic state of Co centers, while the nonmetal-coordinated graphitic N sites act as preferable pollutant adsorption sites and additional PMS activation sites to accelerate electron transfer. Synergistically, CoCN exhibits ultrahigh activity in PMS activation for p-hydroxybenzoic acid oxidation, achieving complete degradation within 10 min with an ultrahigh turnover frequency of 0.38 min-1, surpassing most reported materials. These findings offer new insights into the versatile functions of N species in SACs and inspire rational design of high-performance catalysts in complicated heterogeneous systems.

4.
Chem Asian J ; 18(13): e202300237, 2023 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-37203862

RESUMEN

The radical-bearing epoxy monomer could be the ideal embodiment of multifunctionality in epoxy-based materials. This study demonstrates the potential of macroradical epoxies as surface coating materials. A diepoxide monomer derivatized with a stable nitroxide radical is polymerized with a diamine hardener under the influence of a magnetic field. The magnetically oriented and stable radicals in the polymer backbone render the coatings antimicrobial. The unconventional use of magnets during polymerization proved crucial in correlating the structure-property relationships with antimicrobial performance inferred from oscillatory rheological technique, polarized macro-attenuated total reflectance - infrared (macro-ATR-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The magnetic thermal curing influenced the surface morphology, resulting in a synergy of the coating's radical nature with microbiostatic performance assessed using the Kirby-Bauer test and liquid chromatography - mass spectroscopy (LC-MS). Further, the magnetic curing of blends with a traditional epoxy monomer demonstrates that radical alignment is more critical than radical density in imparting biocidal behavior. This study shows how the systematic use of magnets during polymerization could pave for probing more significant insights into the mechanism of antimicrobial action in radical-bearing polymers.

5.
Nat Commun ; 14(1): 6526, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37845239

RESUMEN

Progress towards the integration of technology into living organisms requires power devices that are biocompatible and mechanically flexible. Aqueous zinc ion batteries that use hydrogel biomaterials as electrolytes have emerged as a potential solution that operates within biological constraints; however, most of these batteries feature inferior electrochemical properties. Here, we propose a biocompatible hydrogel electrolyte by utilising hyaluronic acid, which contains ample hydrophilic functional groups. The gel-based electrolyte offers excellent anti-corrosion ability for zinc anodes and regulates zinc nucleation/growth. Also, the gel electrolyte provides high battery performance, including a 99.71% Coulombic efficiency, over 5500 hours of long-term stability, improved cycle life of 250 hours under a high zinc utilization rate of 80%, and high biocompatibility. Importantly, the Zn//LiMn2O4 pouch cell exhibits 82% capacity retention after 1000 cycles at 3 C. This work presents a promising gel chemistry that controls zinc behaviour, offering great potential in biocompatible energy-related applications and beyond.

6.
J Mater Chem B ; 10(37): 7527-7539, 2022 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-35024716

RESUMEN

In the fight against drug-resistant pathogenic bacterial and fungal cells, low-dimensional materials are emerging as a promising alternative treatment method. Specifically, few-layer black phosphorus (BP) has demonstrated its effectiveness against a wide range of pathogenic bacterial and fungal cells with studies suggesting low cytotoxicity towards healthy mammalian cells. However, the antimicrobial mechanism of action of BP is not well understood. Before new applications for this material can be realised, further in-depth investigations are required. In this work, the biochemical interaction between BP and a series of microbial cells is investigated using a variety of microscopy and spectroscopy techniques to provide a greater understanding of the antimicrobial mechanism. Synchrotron macro-attenuated total reflection-Fourier transform infrared (ATR-FTIR) micro-spectroscopy is used to elucidate the chemical changes occurring outside and within the cell of interest after exposure to BP nanoflakes. The ATR-FTIR data, coupled with high-resolution microscopy, reveals major physical and bio-chemical changes to the phospholipids and amide I and II proteins, as well as minor chemical changes to the structural polysaccharides and nucleic acids when compared to untreated cells. These changes can be attributed to the physical interaction of the BP nanoflakes with the cell membranes, combined with the oxidative stress induced by the degradation of the BP nanoflakes. This study provides insight into the biochemical interaction of BP nanoflakes with microbial cells, allowing for a better understanding of the antimicrobial mechanism of action that will be important for the next generation of applications such as implant coatings, wound dressings, or medical surfaces.


Asunto(s)
Antiinfecciosos , Ácidos Nucleicos , Amidas , Animales , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Análisis de Fourier , Mamíferos , Fósforo , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Sincrotrones
7.
Sovrem Tekhnologii Med ; 12(1): 43-50, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34513036

RESUMEN

The aim of the investigation was to study the integration between native human dental tissue and new-generation biomimetic materials replicating the mineral-organic complex of dentin and enamel using IR microspectroscopy for multidimensional visualization and analysis. MATERIALS AND METHODS: The conditions for stable integration at the interface between biomimetic material and natural hard tissue were identified using a biocomposite buffer system of nanocrystalline carbonate-substituted calcium hydroxyapatite corresponding in its total characteristics to human dentin-enamel apatite and a number of amino acids present in the organic matrix of dentin and enamel: L-histidine, L-lysine hydrochloride, L-arginine hydrochloride, and hyaluronic acid. The finished samples were studied using IR microspectroscopy on IRM channel equipment (The Australian Synchrotron, Melbourne, Australia). RESULTS: The characteristic features of the biomimetic buffer layer at the interface between the enamel and dental material were revealed and visualized based on IR mapping of absorption intensity for particular functional molecular groups with the use of synchrotron radiation, location of the functional groups involved in the processes of biomimetic composite integration was identified.

8.
Nanoscale ; 12(38): 19888-19904, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32985644

RESUMEN

A fungal biofilm refers to the agglomeration of fungal cells surrounded by a polymeric extracellular matrix (ECM). The ECM is composed primarily of polysaccharides that facilitate strong surface adhesion, proliferation, and cellular protection from the surrounding environment. Biofilms represent the majority of known microbial communities, are ubiquitous, and are found on a multitude of natural and synthetic surfaces. The compositions, and in-turn nanomechanical properties, of fungal biofilms remain poorly understood, because these systems are complex, composed of anisotropic cellular and extracellular material, and importantly are species and environment dependent. Therefore, genomic variation, and/or mutations, as well as environmental and growth factors can change the composition of a fungal cell's biofilm. In this work, we probe the physico-mechanical and biochemical properties of two fungal species, Candida albicans (C. albicans) and Cryptococcus neoformans (C. neoformans), as well as two antifungal resistant sub-species of C. neoformans, fluconazole-resistant C. neoformans (FlucRC. neoformans) and amphotericin B-resistant C. neoformans (AmBRC. neoformans). A new experimental methodology of characterization is proposed, employing a combination of atomic force microscopy (AFM), instrumented nanoindentation, and Synchrotron ATR-FTIR measurements. This allowed the nano-mechanical and chemical characterisation of each fungal biofilm.


Asunto(s)
Antifúngicos , Biopelículas , Antifúngicos/farmacología , Candida albicans , Matriz Extracelular , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA