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1.
J Am Chem Soc ; 145(14): 8007-8020, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-36977204

RESUMO

The unique layered structure of graphite with its tunable interlayer distance establishes almost ideal conditions for the accommodation of ions into its structure. The smooth and chemically inert nature of the graphite surface also means that it is an ideal substrate for electrowetting. Here, we combine these two unique properties of this material by demonstrating the significant effect of anion intercalation on the electrowetting response of graphitic surfaces in contact with concentrated aqueous and organic electrolytes as well as ionic liquids. The structural changes during intercalation/deintercalation were probed using in situ Raman spectroscopy, and the results were used to provide insights into the influence of intercalation staging on the rate and reversibility of electrowetting. We show, by tuning the size of the intercalant and the stage of intercalation, that a fully reversible electrowetting response can be attained. The approach is extended to the development of biphasic (oil/water) systems that exhibit a fully reproducible electrowetting response with a near-zero voltage threshold and unprecedented contact angle variations of more than 120° within a potential window of less than 2 V.

2.
J Labelled Comp Radiopharm ; 63(8): 376-385, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32335935

RESUMO

The target of this study is the synthesis of a new diester derivative and radiolabeling with one of the most effective diagnostic radioisotopes to be investigated as a novel targeting radiotracer for tumor imaging. 10-[2-(9-Carboxynonanoyloxy)propoxy]-10-oxodecanoic acid was synthesized in excellent yield and characterized by Fourier-transform infrared spectroscopy, mass, 1 H-NMR, and 13 C-NMR spectra. The diester was technetium-99m (99m Tc) radiolabeled by direct technique using sodium dithionite as a reducing agent. The labeling parameters such as diester amount, reducing agent amount, pH of the medium, and reaction time were optimized. High radiochemical yield of 95.10 ± 0.41% and in vitro stability in serum up to 12 h have been obtained on complexation of the synthesized diester with Tc-99m. Evaluation of the diester anticancer activity against breast cancer cell line (MCF-7) showed high percent of inhibition about 61.5% at 100 µg/ml. The rhenium complex of the diester was synthesized and characterized by liquid chromatography-mass spectrometry (ESI) and elemental analysis depending on the strong chemical resemblance between Tc and Re. Biodistribution studies of 99m Tc-diester complex showed high target to nontarget ratio (T/NT) equals 6.24 ± 0.09 in tumor-bearing mice at 30-min postinjection, suggesting this complex could be used as hopeful solid tumor-imaging agent.


Assuntos
Ésteres/química , Tecnécio/química , Tecnécio/farmacocinética , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Marcação por Isótopo , Camundongos , Radioquímica , Rênio/química , Distribuição Tecidual
3.
Nanoscale ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958552

RESUMO

The nanoscale form of the Chevrel phase, Mo6S8, is demonstrated to be a highly efficient zinc-free anode in aqueous zinc ion hybrid supercapacitors (ZIHSCs). The unique morphological characteristics of the material when its dimensions approach the nanoscale result in fast zinc intercalation kinetics that surpass the ion transport rate reported for some of the most promising materials, such as TiS2 and TiSe2. In situ Raman spectroscopy, post-mortem X-ray diffraction, Hard X-ray photoelectron spectroscopy, and density functional theory (DFT) calculations were combined to understand the overall mechanism of the zinc ion (de)intercalation process. The previously unknown formation of the sulfur-deficient Zn2.9Mo15S19 (Zn1.6Mo6S7.6) phase is identified, leading to a re-evaluation of the mechanism of the (de)intercalation process. A full cell comprised of an activated carbon (YEC-8A) positive electrode delivers a cell capacity of 38 mA h g-1 and an energy density of 43.8 W h kg-1 at a specific current density of 0.2 A g-1. The excellent cycling stability of the device is demonstrated for up to 8000 cycles at 3 A g-1 with a coulombic efficiency close to 100%. Post-mortem microscopic studies reveal the absence of dendrite formation at the nanosized Mo6S8 anode, in stark contrast to the state-of-the-art zinc electrode.

4.
Chirurgie (Heidelb) ; 94(11): 940-947, 2023 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-37500803

RESUMO

Robot-assisted systems have been increasingly used in general surgery for several years. Accordingly, the number of systems installed in Germany has also rapidly increased. While around 100 robot-assisted systems were used in German hospitals in 2018, this figure had already risen to more than 200 by 2022. The aim of this article is to present the current state of development and trends in robotic surgery in Germany. For this purpose, data from the StuDoQ|Robotics register were analyzed. Furthermore, a descriptive analysis of concomitant diagnosis-related groups (DRG) data was carried out via the Federal Statistical Office (Destatis), for a better assessment of the representativeness of the StuDoQ|Robotics register data. In both data sets, the annual number of robot-assisted visceral surgery procedures in Germany steadily increased. Compared to the DRG data, only 3.7% up to a maximum of 36.7% of all robot-assisted procedures performed were documented in the StuDoQ|Robotics register, depending on the type of procedure. Colorectal resections were the most frequent robot-assisted procedures (StuDoQ: 32.5% and 36.7% vs. DRG data: 24.2% and 29.7%) and had, for example, low mortality rates (StuDoQ: 1% and 1% vs. DRG data: 2.3% and 1.3%). Due to the low coverage rates of robot-assisted esophageal, gastric, pancreatic and liver interventions, no valid statements could be derived from the StuDoQ data for these areas. With the current coverage rates, the informative value of the StuDoQ|Robotics register is considerably limited for some types of intervention. In the future, measures should therefore be explored that lead to a significant increase in the coverage rates.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório , Procedimentos Cirúrgicos Robóticos , Robótica , Alemanha/epidemiologia , Sistema de Registros
5.
ACS Omega ; 8(27): 24218-24232, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37457481

RESUMO

The study investigates the potential of Cupressus sempervirens (EO) as a sustainable and eco-friendly inhibitor of copper corrosion in a 0.5 M sulfuric acid medium. The electrochemical impedance spectroscopy analysis shows that the effectiveness of corrosion inhibition rises with increasing inhibitor concentrations, reaching 94% with the application of 2 g/L of EO, and potentiodynamic polarization (PDP) studies reveal that EO functions as a mixed-type corrosion inhibitor. In addition, the Langmuir adsorption isotherm is an effective descriptor of its adsorption. Scanning electron microscopy/energy-dispersive X-ray spectroscopy, atomic force microscopy surface examination, and contact angle measurement indicate that EO may form a barrier layer on the metal surface. Density functional theory calculations, Monte Carlo simulation models, and the radial distribution function were also used to provide a more detailed understanding of the corrosion protection mechanism. Overall, the findings suggest that Cupressus sempervirens (EO) has the potential to serve as an effective and sustainable corrosion inhibitor for copper in a sulfuric acid medium, contributing to the development of green corrosion inhibitors for environmentally friendly industrial processes.

6.
Chem Mater ; 35(19): 7904-7914, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37840778

RESUMO

High entropy metal chalcogenides are materials containing five or more elements within a disordered sublattice. These materials exploit a high configurational entropy to stabilize their crystal structure and have recently become an area of significant interest for renewable energy applications such as electrocatalysis and thermoelectrics. Herein, we report the synthesis of bulk particulate HE zinc sulfide analogues containing four, five, and seven metals. This was achieved using a molecular precursor cocktail approach with both transition and main group metal dithiocarbamate complexes which are decomposed simultaneously in a rapid (1 h) and low-temperature (500 °C) thermolysis reaction to yield high entropy and entropy-stabilized metal sulfides. The resulting materials were characterized by powder XRD, SEM, and TEM, alongside EDX spectroscopy at both the micro- and nano-scales. The entropy-stabilized (CuAgZnCoMnInGa)S material was demonstrated to be an excellent electrocatalyst for the hydrogen evolution reaction when combined with conducting carbon black, achieving a low onset overpotential of (∼80 mV) and η10 of (∼255 mV).

7.
Adv Sci (Weinh) ; 10(14): e2204488, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36951493

RESUMO

High-entropy (HE) metal chalcogenides are a class of materials that have great potential in applications such as thermoelectrics and electrocatalysis. Layered 2D transition-metal dichalcogenides (TMDCs) are a sub-class of high entropy metal chalcogenides that have received little attention to date as their preparation currently involves complicated, energy-intensive, or hazardous synthetic steps. To address this, a low-temperature (500 °C) and rapid (1 h) single source precursor approach is successfully adopted to synthesize the hexernary high-entropy metal disulfide (MoWReMnCr)S2 . (MoWReMnCr)S2 powders are characterized by powder X-ray diffraction (pXRD) and Raman spectroscopy, which confirmed that the material is comprised predominantly of a hexagonal phase. The surface oxidation states and elemental compositions are studied by X-ray photoelectron spectroscopy (XPS) whilst the bulk morphology and elemental stoichiometry with spatial distribution is determined by scanning electron microscopy (SEM) with elemental mapping information acquired from energy-dispersive X-ray (EDX) spectroscopy. The bulk, layered material is subsequently exfoliated to ultra-thin, several-layer 2D nanosheets by liquid-phase exfoliation (LPE). The resulting few-layer HE (MoWReMnCr)S2 nanosheets are found to contain a homogeneous elemental distribution of metals at the nanoscale by high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) with EDX mapping. Finally, (MoWReMnCr)S2 is demonstrated as a hydrogen evolution electrocatalyst and compared to 2H-MoS2 synthesized using the molecular precursor approach. (MoWReMnCr)S2 with 20% w/w of high-conductivity carbon black displays a low overpotential of 229 mV in 0.5 M  H2 SO4 to reach a current density of 10 mA cm-2 , which is much lower than the overpotential of 362 mV for MoS2 . From density functional theory calculations, it is hypothesised that the enhanced catalytic activity is due to activation of the basal plane upon incorporation of other elements into the 2H-MoS2 structure, in particular, the first row TMs Cr and Mn.

8.
ACS Appl Mater Interfaces ; 14(22): 25232-25245, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35622978

RESUMO

Aqueous rechargeable batteries based on aluminum chemistry have become the focus of immense research interest owing to their earth abundance, low cost, and the higher theoretical volumetric energy density of this element compared to lithium-ion batteries. Efforts to harness this huge potential have been hindered by the narrow potential window of water and by passivating effects of the high-electrical band-gap aluminum oxide film. Herein, we report a high-performing aqueous aluminum-ion battery (AIB), which is constructed using a Zn-supported Al alloy, an aluminum bis(trifluoromethanesulfonyl)imide (Al[TFSI]3) electrolyte, and a MnO2 cathode. The use of Al[TFSI]3 significantly extends the voltage window of the electrolyte and enables the cell to access Al3+/Al electrochemistry, while the use of Zn-Al alloy mitigates the issue of surface passivation. The Zn-Al alloy, which is produced by in situ electrochemical deposition, obtained from Al[TFSI]3 showed excellent long-term reversibility for Al electrochemistry and displays the highest performance in AIB when compared to the response obtained in Al2(SO4)3 or aluminum trifluoromethanesulfonate electrolyte. AIB cells constructed using the Zn-Al|Al[TFSI]3|MnO2 combination achieved a record discharge voltage plateau of 1.75 V and a specific capacity of 450 mAh g-1 without significant capacity fade after 400 cycles. These findings will promote the development of energy-dense aqueous AIBs.

9.
Nanoscale ; 14(28): 10125-10135, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35792825

RESUMO

The development of intrinsically safe and environmentally sustainable energy storage devices is a significant challenge. Recent advances in aqueous rechargeable lithium-ion batteries (ARLIBs) have made considerable steps in this direction. In parallel to the ongoing progress in the design of aqueous electrolytes that expand the electrochemically stable potential window, the design of negative electrode materials exhibiting large capacity and low intercalation potential attracts great research interest. Herein, we report the synthesis of high purity nanoscale Chevrel Phase (CP) Mo6S8via a simple, efficient and controllable molecular precursor approach with significantly decreased energy consumption compared to the conventional approaches. Physical characterization of the obtained product confirms the successful formation of CP-Mo6S8 and reveals that it is crystalline nanostructured in nature. Due to their unique structural characteristics, the Mo6S8 nanocubes exhibit fast kinetics in a 21 m lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolyte as a result of the shorter Li+ ion diffusion distance. Full battery cells comprised of Mo6S8 and LiMn2O4 as negative and positive electrode materials, respectively, operate at 2.23 V delivering a high energy density of 85 W h kg-1 (calculated on the total mass of active materials) under 0.2 C-rate. At 4 C, the coulombic efficiency (CE) is determined to be 99% increasing to near 100% at certain cycles. Post-mortem physical characterization demonstrates that the Mo6S8 anode maintained its crystallinity, thereby exhibiting outstanding cycling stability. The cell outperforms the commonly used vanadium-based (VO2 (B), V2O5) or (NASICON)-type LiTi2(PO4)3 anodes, highlighting the promising character of the nanoscale CP-Mo6S8 as a highly efficient anode material. In summary, the proposed synthetic strategy is expected to stimulate novel research towards the widespread application of CP-based materials in various aqueous and non-aqueous energy storage systems.

10.
ACS Omega ; 6(13): 8894-8907, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33842760

RESUMO

The inhibitory impact of low-cost synthesized pyrazoline derivatives named Pz series (Pz1 and Pz2) on the corrosion of API 5L X60 carbon steel in 5 M HCl was inspected to serve as corrosion inhibitors against such a solution for its usage in the oilfield well acidization process. Also, the same compounds were unitized as biocides for sulfate-reducing bacteria (SRBs) to inhibit the microbial-induced corrosion effect. This study was conducted via several electrochemical techniques, namely, electrochemical potentiodynamic polarization (EP) and electrochemical impedance spectroscopy (EIS), in addition to computational density functional theory (DFT). The inhibition efficiency (IE) of Pz series on the corrosion of 5L X60 carbon steel in 5 M HCl was found to increase whenever the Pz series molecule concentration was increased. EP measurements revealed that Pz1 and Pz2 have both cathodic and anodic features (mixed inhibitor) and their corrosion IEs were around 90%. The physicochemical properties of the Pz1 and Pz2 compounds were studied using Langmuir adsorption isotherms, where the equilibrium adsorption data were found to follow it accurately. EIS outputs were found to comply with the values obtained from EP. Scanning electron microscopy was used to examine the topographic anisotropy between the inhibited and uninhibited 5L X60 carbon steel samples to double-check the electrochemical findings. DFT calculations and Monte Carlo simulations were utilized to predict the behavior of inhibitors and to rationalize the experimental results. The serial dilution bioassay technique was used to assess the Pz series as potential biocides to counter the effect of SRBs in compliance with the TM0194-2014-SG standard test method, and the results showed the potency of Pz series in inhibiting such bacterial growth.

11.
RSC Adv ; 9(19): 10473-10485, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35515280

RESUMO

In this work, we report the synthesis of two Schiff bases of substituted gallic acid derivatives via amidation reaction and their characterization using 1H-NMR spectroscopy to study their inhibition performance on the aggressive attack of HCl on mild steel (MS). The inhibitive performance was examined using chemical (weight loss) and electrochemical (Tafel and EIS) test methods. The results indicate that these derivatives significantly suppress the dissolution rate of mild steel via adsorption phenomena, which correlates to the Langmuir adsorption model. Tafel data display the mixed-type properties of these compounds and EIS results show that increasing Schiff base concentration not only leads to delaying the charge transfer (R ct) of iron from 26.4 ohm cm-2 to 227.7 ohm cm-2 but also decreases the capacitance of the adsorbed double layer (C dl) from 8.58 (F cm-2) × 10-5 to 2.55 (F cm-2) × 10-5. The inhibition efficiency percentage reaches the peak (90%) at optimum concentration of 250 ppm. The Monte Carlo simulations confirm the adsorption ability of the as-prepared compounds on the Fe (1 1 0) crystal. The SEM/EDX results revealed the presence of a protective film on the mild steel sample.

12.
RSC Adv ; 9(72): 42120-42131, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-35542890

RESUMO

The inhibition impacts of two non-toxic glycine derivatives, namely, bicine (N,N-bis(2-hydroxyethyl)glycine) and tricine (N-(tri(hydroxymethyl)methyl) glycine) on copper corrosion were investigated in 3.5% NaCl solutions. Surprisingly, there is no report on using bicine and/or tricine as corrosion inhibitors for Cu and its alloys in a seawater-like environment. The effects of bicine and tricine on the corrosion behavior of Cu in 3.5% NaCl were examined using the open circuit potential, Tafel polarization, and AC spectroscopy (EIS) techniques. The corrosion rate decreased as a function of the inhibitor dose. The Tafel and EIS parameters showed that the inhibitors decreased both the anodic and cathodic corrosion currents and inhibited the charge transfer process by adsorption on the Cu surface. The inhibition property was attributed to the adsorption of inhibitor molecules with the Langmuir model. Tricine showed a superior inhibition performance of more than 98% at a concentration of ∼5 mmol L-1. The free energy of adsorption data revealed physical adsorption. The outcomes of Monte Carlo simulations and theoretical studies well supported the experimental data.

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