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1.
Nano Lett ; 24(5): 1544-1552, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38270095

RESUMEN

Lithium-metal (Li0) anodes potentially enable all-solid-state batteries with high energy density. However, it shows incompatibility with sulfide solid-state electrolytes (SEs). One strategy is introducing an interlayer, generally made of a mixed ionic-electronic conductor (MIEC). Yet, how Li behaves within MIEC remains unknown. Herein, we investigated the Li dynamics in a graphite interlayer, a typical MIEC, by using operando neutron imaging and Raman spectroscopy. This study revealed that intercalation-extrusion-dominated mechanochemical reactions during cell assembly transform the graphite into a Li-graphite interlayer consisting of SE, Li0, and graphite-intercalation compounds. During charging, Li+ preferentially deposited at the Li-graphite|SE interface. Upon further plating, Li0-dendrites formed, inducing short circuits and the reverse migration of Li0. Modeling indicates the interface has the lowest nucleation barrier, governing lithium transport paths. Our study elucidates intricate mechano-chemo-electrochemical processes in mixed conducting interlayers. The behavior of Li+ and Li0 in the interlayer is governed by multiple competing factors.

2.
Adv Mater ; 33(52): e2105505, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34655125

RESUMEN

Current sulfide solid-state electrolyte (SE) membranes utilized in all-solid-state lithium batteries (ASLBs) have a high thickness (0.5-1.0 mm) and low ion conductance (<25 mS), which limit the cell-level energy and power densities. Based on ethyl cellulose's unique amphipathic molecular structure, superior thermal stability, and excellent binding capability, this work fabricates a freestanding SE membrane with an ultralow thickness of 47 µm. With ethyl cellulose as an effective disperser and a binder, the Li6 PS5 Cl is uniformly dispersed in toluene and possesses superior film formability. In addition, an ultralow areal resistance of 4.32 Ω cm-2 and a remarkable ion conductance of 291 mS (one order higher than the state-of-the-art sulfide SE membrane) are achieved. The ASLBs assembled with this SE membrane deliver cell-level high gravimetric and volumetric energy densities of 175 Wh kg-1 and 675 Wh L-1 , individually.

3.
Carbohydr Polym ; 256: 117525, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483046

RESUMEN

Microfibrillated cellulose (MFC) is widely used as a reinforcement filler for biocomposites due to its unique properties. However, the challenge of drying MFC and the incompatibility between nanocellulose and polymer matrix still limits the mechanical performance of MFC-reinforced biocomposites. In this study, we used a water-based transesterification reaction to functionalize MFC and explored the capability of oven-dried MFC as a reinforcement filler for polylactic acid (PLA). Remarkably, this oven-dried, vinyl laurate-modified MFC improved the tensile strength by 38 % and Young's modulus by 71 % compared with neat PLA. Our results suggested improved compatibility and dispersion of the fibrils in PLA after modification. This study demonstrated that scalable water-based surface modification and subsequent straightforward oven drying could be a facile method for effectively drying cellulose nanomaterials. The method helps significantly disperse fibrils in polymers and enhances the mechanical properties of microfibrillar cellulose-reinforced biocomposites.


Asunto(s)
Celulosa/química , Lauratos/química , Nanocompuestos/química , Poliésteres/química , Compuestos de Vinilo/química , Rastreo Diferencial de Calorimetría , Celulosa/ultraestructura , Desecación/métodos , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Nanocompuestos/ultraestructura , Propiedades de Superficie , Resistencia a la Tracción , Termogravimetría , Agua/química
4.
ACS Appl Mater Interfaces ; 9(16): 14506-14517, 2017 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-28368569

RESUMEN

In this work, nanoporous boron nitride sample was synthesized with a Brunauer-Emmett-Teller (BET) surface area of 1360 m2/g and particle size 5-7 µm. The boron nitride was characterized with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and electron microscopy (TEM and SEM). Thermogravimetric analysis (TGA) under nitrogen and air and subsequent analysis with XPS and XRD suggested that its structure is stable in air up to 800 °C and in nitrogen up to 1050 °C, which is higher than most of the common adsorbents reported so far. Nitrogen and hydrocarbon adsorption at 298 K and pressure up to 1 bar suggested that all hydrocarbon adsorption amounts were higher than that of nitrogen and the adsorbed amount of hydrocarbon increases with an increase in its molecular weight. The kinetics of adsorption data suggested that adsorption becomes slower with the increase in molecular weight of hydrocarbons. The equilibrium data suggested that that boron nitride is selective to paraffins in a paraffin-olefin mixture and hence may act as an "olefin generator". The ideal adsorbed solution theory (IAST)-based selectivity for CH4/N2, C2H6/CH4, and C3H8/C3H6 was very high and probably higher than the majority of adsorbents reported in the literature. IAST-based calculations were also employed to simulate the binary mixture adsorption data for the gas pairs of CH4/N2, C2H6/CH4, C2H6/C2H4, and C3H8/C3H6. Finally, a simple mathematical model was employed to simulate the breakthrough behavior of the above-mentioned four gas pairs in a dynamic column experiment. The overall results suggest that nanoporous boron nitride can be used as a potential adsorbent for light hydrocarbon separation.

5.
Plast Reconstr Surg ; 139(3): 625-637, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28234837

RESUMEN

BACKGROUND: Although chemical antiseptics are the most basic measure to control wound infection and frequently come into contact with subcutaneous adipose tissue, no studies have evaluated their toxicity on adipose tissue and its cell fractions. In the present study, the effects of five different antiseptics on adipose-derived stem cells were evaluated. METHODS: Human adipose-derived stem cells were harvested from healthy donors. Adipose-derived stem cell viability was measured after treatment with different concentrations of antiseptics over 5 days. Furthermore, the effect on the proliferation, adipogenic differentiation, and apoptosis/necrosis of adipose-derived stem cells was analyzed. Finally, the mRNA expression of the stem cell markers CD29, CD34, CD73, CD90, and CD105 was detected. RESULTS: Octenisept and Betaisodona significantly reduced cell proliferation and differentiation and led to considerable adipose-derived stem cell necrosis. Octenisept decreased stem cell viability at the lowest concentrations tested, and all stem cell markers were down-regulated by Octeniseptr and Betaisodona. Lavasept and Prontosan both led to reduced stem cell viability, proliferation, and differentiation, and increased apoptosis/necrosis, although the effects were less pronounced compared with Octenisept and Betaisodona. Adipose-derived stem cells survived treatment with mafenide acetate even at high concentrations, and mafenide acetate showed minimal negative effects on their proliferation, adipogenic differentiation, cell death, and stem cell marker expression. CONCLUSIONS: Mafenide acetate may be regarded as a feasible antiseptic for the treatment of wounds with exposed adipose tissue because of its low adipose-derived stem cell toxicity. Lavasept and Prontosan are possible alternatives to mafenide acetate. Octenisept and Betaisodona, by contrast, may be used only in highly diluted solutions. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.


Asunto(s)
Adipocitos/citología , Tejido Adiposo/citología , Antiinfecciosos Locales/farmacología , Células Madre/efectos de los fármacos , Adulto , Supervivencia Celular/efectos de los fármacos , Femenino , Humanos , Masculino , Factores de Tiempo
6.
J Plast Reconstr Aesthet Surg ; 66(1): 137-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22652291

RESUMEN

Anomalies of muscles of the upper extremity are frequently encountered and anatomic variations of the flexor digitorum superficialis (FDS) muscle-tendon unit are frequently reported by anatomists and clinicians. FDS anomalies can be in forms of tendon interconnections, substitution, absence or muscle belly variations and most of the times the anomalies of FDS produce few clinical symptoms. We report a rare and unusual case of FDS anomaly with a unique and large muscle belly. The deformity is type V according to the classification of Elliot et al. in which the muscle belly extends to four digits (the index, middle, ring and little finger) in the right hand of patient and there is absence of the palmaris longus tendon. The hand surgeon should be able to realise all variations of the FDS tendon and should be prepared for unexpected findings during surgery.


Asunto(s)
Antebrazo/anomalías , Músculo Esquelético/anomalías , Tendones/anomalías , Adulto , Traumatismos del Antebrazo/cirugía , Humanos , Hallazgos Incidentales , Masculino , Músculo Esquelético/patología
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