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1.
Sci Rep ; 14(1): 22854, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39353994

RESUMEN

Gold nanodendrite (AuND) is a type of gold nanoparticles with dendritic or branching structures that offers advantages such as large surface area and high conductivity to improve electrocatalytic performance of electrochemical sensors. AuND structures can be synthesized using electrodeposition method utilizing cysteine as growth directing agent. This method can simultaneously synthesize and integrate the gold nanostructures on the surface of the electrode. We conducted a comprehensive study on the synthesis of AuND on screen-printed carbon electrode (SPCE)-based working electrode, focusing on the optimization of electrodeposition parameters, such as applied potential, precursor solution concentration, and deposition time. The measured surface oxide reduction peak current and electrochemical surface area from cyclic voltammogram were used as the optimization indicators. We confirmed the growth of dendritic gold nanostructures across the carbon electrode surface based on FESEM, EDS, and XRD characterizations. We applied the SPCE/AuND electrode as a nonenzymatic sensor on ascorbic acid (AA) and obtained detection limit of 16.8 µM, quantification limit of 51.0 µM, sensitivity of 0.0629 µA µM-1, and linear range of 180-2700 µM (R2 value = 0.9909). Selectivity test of this electrode against several interferences, such as uric acid, dopamine, glucose, and urea, also shows good response in AA detection.


Asunto(s)
Ácido Ascórbico , Carbono , Electrodos , Oro , Nanopartículas del Metal , Oro/química , Ácido Ascórbico/análisis , Carbono/química , Nanopartículas del Metal/química , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Galvanoplastia/métodos , Límite de Detección , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación
2.
Int J Mol Sci ; 25(18)2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39337260

RESUMEN

This study investigates the immobilization of cyanobacterial photosystem I (PSI) from Synechocystis sp. PCC 6803 onto fluorine-doped tin oxide (FTO) conducting glass plates to create photoelectrodes for biohybrid solar cells. The fabrication of these PSI-FTO photoelectrodes is based on two immobilization processes: rapid electrodeposition driven by an external electric field and slower adsorption during solvent evaporation, both influenced by gravitational sedimentation. Deposition and performance of photoelectrodes was investigated by UV-Vis absorption spectroscopy and photocurrent measurements. We investigated the efficiency of PSI immobilization under varying conditions, including solution pH, applied electric field intensity and duration, and electrode polarization, with the goals to control (1) the direction of migration and (2) the orientation of the PSI particles on the substrate surface. Variation in the pH value of the PSI solution alters the surface charge distribution, affecting the net charge and the electric dipole moment of these proteins. Results showed PSI migration to the positively charged electrode at pH 6, 7, and 8, and to the negatively charged electrode at pH 4.4 and 5, suggesting an isoelectric point of PSI between 5 and 6. At acidic pH, the electrophoretic migration was largely hindered by protein aggregation. Notably, photocurrent generation was consistently cathodic and correlated with PSI layer thickness, and no conclusions can be drawn on the orientation of the immobilized proteins. Overall, these findings suggest mediated electron transfer from FTO to PSI by the used electrolyte containing 10 mM sodium ascorbate and 200 µM dichlorophenolindophenol.


Asunto(s)
Electrodos , Complejo de Proteína del Fotosistema I , Compuestos de Estaño , Compuestos de Estaño/química , Complejo de Proteína del Fotosistema I/química , Complejo de Proteína del Fotosistema I/metabolismo , Synechocystis/química , Synechocystis/metabolismo , Concentración de Iones de Hidrógeno , Galvanoplastia/métodos , Flúor/química , Proteínas Inmovilizadas/química , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo
3.
ACS Appl Mater Interfaces ; 16(34): 44538-44548, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39072533

RESUMEN

Temperature has a profound influence on various neuromodulation processes and has emerged as a focal point. However, the effects of acute environmental temperature fluctuations on cultured cortical networks have been inadequately elucidated. To bridge this gap, we have developed a brain-on-a-chip platform integrating cortical networks and electrodeposited Pt/Ir modified microelectrode arrays (MEAs) with 3D-printed bear-shaped triple chambers, facilitating control of temperature transients. This innovative system administers thermal stimuli while concurrently monitoring neuronal activity, including spikes and local field potentials, from 60 microelectrodes (diameter: 30 µm; impedance: 9.34 ± 1.37 kΩ; and phase delay: -45.26 ± 2.85°). Temperature transitions of approximately ±10 °C/s were applied to cortical networks on MEAs via in situ perfusion within the triple chambers. Subsequently, we examined the spatiotemporal dynamics of the brain-on-a-chip under temperature regulation at both the group level (neuronal population) and their interactions (network dynamics) and the individual level (cellular activity). Specifically, we found that after the temperature reduction neurons enhanced the overall information transmission efficiency of the network through synchronous firing to compensate for the decreased efficiency of single-cell level information transmission, in contrast to temperature elevation. By leveraging the integration of high-performance MEAs with perfusion chambers, this investigation provides a comprehensive understanding of the impact of temperature on the spatiotemporal dynamics of neural networks, thereby facilitating future exploration of the intricate interplay between temperature and brain function.


Asunto(s)
Microelectrodos , Neuronas , Platino (Metal) , Temperatura , Animales , Platino (Metal)/química , Neuronas/fisiología , Iridio/química , Corteza Cerebral/fisiología , Galvanoplastia/métodos , Ratas
4.
Biosens Bioelectron ; 261: 116418, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38875864

RESUMEN

Electroplating of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is important in many neuroelectronic applications but is challenging to achieve uniformity on large-scale microelectrode arrays (MEA) using conventional galvanostatic methods. In this study, we address this challenge through a potentiostatic method and demonstrate highly uniform electroplating of PEDOT:PSS on MEA with more than one hundred electrodes, all at cellular sizes. The validation of this approach involves comparisons with galvanostatic deposition methods, showcasing unparalleled deposition yield and uniformity. Systematic electrochemical characterizations reveal similarities in structure and stability from potentiostatic deposited coatings. The advances developed here establish the potentiostatic method and detailed process to achieve a uniform coating of PEDOT:PSS on large-scale MEA, with broad utility in neuroelectronics.


Asunto(s)
Microelectrodos , Poliestirenos , Poliestirenos/química , Galvanoplastia/métodos , Técnicas Biosensibles/métodos , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Polímeros/química , Animales , Técnicas Electroquímicas/métodos , Tiofenos
5.
Anal Methods ; 16(16): 2424-2443, 2024 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-38592715

RESUMEN

This review summarizes recent developments in amperometric biosensors, based on one-step electrodeposited organic-inorganic hybrid layers, used for analysis of low molecular weight compounds. The factors affecting self-assembly of one-step electrodeposited films, methods for verifying their composition, advantages, limitations and approaches affecting the electroanalytical performance of amperometric biosensors based on organic-inorganic hybrid layers were systemized. Moreover, issues related to the formation of one-step organic-inorganic hybrid functional layers with different structures in biosensors produced under the same electrodeposition parameters are discussed. The systemized dependencies can support the preliminary choice of functional sensing layers with architectures tuned for specific biotechnology and life science applications. Finally, the capabilities of one-step electrodeposition of organic-inorganic hybrid functional films beyond amperometric biosensors were highlighted.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Galvanoplastia/métodos , Nanoestructuras/química , Electrodos
6.
Environ Sci Pollut Res Int ; 30(57): 119893-119902, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37932614

RESUMEN

The electroplating process of copper pyrophosphate (Cu2P2O7) results in the production of a large volume of wastewater that contains a high concentration of copper (Cu). Currently, conventional lime precipitation creates a substantial amount of secondary pollution, which adds extra economic and environmental burdens. In this study, we suggest a straightforward method for on-site recovery of Cu from Cu2P2O7 electroplating wastewater. By optimizing various parameters, characterizing the resulting product, assessing its electroplating capabilities, and analyzing the speciation during the reaction, we comprehensively investigated the feasibility and mechanism of this technique. The results demonstrated that, under the optimal conditions (Cu/P molar ratio of 0.96, pH of 5.0, and a reaction time of 5.0 min), the concentration of residual Cu remained stable between 22.2 and 27.7 mg/L, even when the initial Cu concentrations varied. The addition of Cu triggered a series of hydrolysis and ionization reactions, primarily leading to the formation of Cu2P2O7·3H2O. The harvested Cu2P2O7·3H2O proved to be suitable for practical electroplating applications, exhibiting comparable performance to commercially available Cu2P2O7·3H2O. This demonstrates the feasibility of recovering high-purity Cu2P2O7·3H2O from copper electroplating wastewater, offering a promising approach for on-site copper reuse and concurrently reducing the demand for natural copper resources. Furthermore, this approach significantly reduces the generation of solid waste, aligning with the principles of sustainable development.


Asunto(s)
Aguas Residuales , Contaminantes Químicos del Agua , Cobre/química , Galvanoplastia/métodos , Difosfatos , Contaminantes Químicos del Agua/análisis
7.
Chemosphere ; 343: 140142, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37716565

RESUMEN

The application of PbO2 for electrochemical oxidation technology is limited by its low electrocatalytic activity and short service life. Herein, based on the facile one-step electrodeposition, we prepared a boron carbide (B4C) and cerium (Ce) co-modified Ti/PbO2 (Ti/PbO2-B4C-Ce) electrode to overcome these shortcomings. Compared with Ti/PbO2 electrode, the denser surface is displayed by Ti/PbO2-B4C-Ce electrode. Meanwhile, electrochemical characterization indicates that the introduction of B4C and Ce significantly enhance the electrochemical performance of PbO2 electrode. In degradation experiments, under optimized conditions (current density 20 mA cm-2, pH 9, 0.15 M Na2SO4 and 30 °C), the fully degradation of tetracycline (TC) can be completed within 30 min. Furthermore, the trapping experiment demonstrates that ∙OH and SO4·- radicals have a synergistic effect in the degradation process of TC. Based on results of liquid chromatography-mass spectrometer, the generated ·OH preferentially attacks amides, phenols and conjugated double bond groups in TC. Importantly, Ti/PbO2-B4C-Ce electrode maintains a constant degradation efficiency even after 10 recycling tests, and its service life is 2.4 times of traditional Ti/PbO2 electrode. Hence, Ti/PbO2-B4C-Ce electrode is a promising electrode for degradation of organic wastewater containing amides, phenols, and conjugated double bond groups.


Asunto(s)
Cerio , Contaminantes Químicos del Agua , Galvanoplastia/métodos , Óxidos/química , Titanio/química , Contaminantes Químicos del Agua/análisis , Oxidación-Reducción , Antibacterianos , Tetraciclina , Electrodos , Amidas , Fenoles
8.
Colloids Surf B Biointerfaces ; 225: 113287, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37004387

RESUMEN

The main goal of this work is to open new perspectives in the field of electrodeposition and provide green alternatives to the electroplating industry. The effect of different anions (SO42-, ClO3-, NO3-, ClO4-, BF4-, PF6-) in solution on the electrodeposition of copper was investigated. The solutions, containing only the copper precursor and the background electrolyte, were tailored to minimize the environmental impact and reduce the use of organic additives and surfactants. The study is based on electrochemical measurements carried out to verify that no metal complexation takes place. We assessed the nucleation and growth mechanism, we performed a morphological characterization through scanning electron microscopy and deposition efficiency by measuring the film thickness through X-ray fluorescence spectroscopy. Significant differences in the growth mechanism and in the morphology of the electrodeposited films, were observed as a function of the background electrolyte.


Asunto(s)
Cobre , Galvanoplastia , Cobre/química , Galvanoplastia/métodos , Microscopía Electrónica de Rastreo , Aniones , Electrólitos/química
9.
Small ; 18(47): e2203555, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36192153

RESUMEN

Metallic barcode nanowires (BNWs) composed of repeating heterogeneous segments fabricated by template-assisted electrodeposition can offer extended functionality in magnetic, electrical, mechanical, and biomedical applications. The authors consider such nanostructures as a 3D system of magnetically interacting elements with magnetic behavior strongly affected by complex magnetostatic interactions. This study discusses the influence of geometrical parameters of segments on the character of their interactions and the overall magnetic behavior of the array of BNWs having alternating magnetization, because the Fe and Au segments are made of Fe-Au alloys with high and low magnetizations. By controlling the applied current densities and the elapsed time in the electrodeposition, the dimension of the Fe-Au BNWs can be regulated. This study reveals that the influence of the length of magnetically weak Au segments on the interaction field between nanowires is different for samples with magnetically strong 100 and 200 nm long Fe segments using the first-order reversal curve (FORC) diagram method. With the help of micromagnetic simulations, three types of magnetostatic interactions in the BNW arrays are discovered and analy. This study demonstrates that the dominating type of interaction depends on the geometric parameters of the Fe and Au segments and the interwire and intrawire distances.


Asunto(s)
Nanoestructuras , Nanocables , Nanocables/química , Nanoestructuras/química , Galvanoplastia/métodos , Magnetismo
10.
J Appl Biomater Funct Mater ; 20: 22808000221103970, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35946407

RESUMEN

In cases of severe bone tissue injuries, the use of metallic bioimplants is quite widespread due to their high strength, high fracture toughness, hardness, and corrosion resistance. However, they lack adequate biocompatibility and show poor metal-tissue integration during the post-operative phase. To mitigate this drawback, it is beneficial to add a biocompatible polymer layer to ensure a quick growth of cell or tissue over the surface of metallic bioimplant material. Furthermore, this additional layer should possess good adherence with the underlying material and also accompany a rapid bonding between the tissue and the implant material, in order to reduce the recovery time for the patient. Therefore, in this work, we report a novel green electroplating route for growing porous hydroxyapatite-brushite coatings on a stainless steel surface. The malic acid used for the production of hydroxyapatite-brushite coatings has been obtained from an extract of locally available apple fruit (Malus domestica). We demonstrate the effect of electroplating parameters on the structural morphology of the electroplated composite layer via XRD, SEM with EDS, and FTIR characterization techniques and report an optimized set of electroplating parameters that will yield the best composite coating in terms of thickness, adherence to substrate and speed. The hemocompatibility and osteocompatibility studies on the electroplated composites coating show this technology's effectiveness and potential applicability in biomedical applications. Compared to other routes reported in the literature, this electroplating route is quicker and yields better composite coatings with faster bone tissue growth potential.


Asunto(s)
Materiales Biocompatibles Revestidos , Galvanoplastia , Fosfatos de Calcio , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Corrosión , Durapatita/química , Galvanoplastia/métodos , Humanos , Propiedades de Superficie , Difracción de Rayos X
11.
Int J Mol Sci ; 23(3)2022 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-35163817

RESUMEN

For decades, Ta/TaN has been the industry standard for a diffusion barrier against Cu in interconnect metallisation. The continuous miniaturisation of transistors and interconnects into the nanoscale are pushing conventional materials to their physical limits and creating the need to replace them. Binary metallic systems, such as Ru-W, have attracted considerable attention as possible replacements due to a combination of electrical and diffusion barrier properties and the capability of direct Cu electroplating. The process of Cu electrodeposition on Ru-W is of fundamental importance in order to create thin, continuous, and adherent films for advanced interconnect metallisation. This work investigates the effects of the current density and application method on the electro-crystallisation behaviour of Cu. The film structure, morphology, and chemical composition were assessed by digital microscopy, atomic force microscopy, scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The results show that it was possible to form a thin Cu film on Ru-W with interfacial continuity for current densities higher than 5 mA·cm-2; however, the substrate regions around large Cu particles remained uncovered. Pulse-reverse current application appears to be more beneficial than direct current as it decreased the average Cu particle size.


Asunto(s)
Cobre/química , Galvanoplastia/métodos , Rutenio/química , Tungsteno/química , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Miniaturización , Espectrometría por Rayos X , Difracción de Rayos X
12.
Environ Sci Pollut Res Int ; 29(48): 72196-72246, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35084684

RESUMEN

Water pollution by recalcitrant compounds is an increasingly important problem due to the continuous introduction of new chemicals into the environment. Choosing appropriate measures and developing successful strategies for eliminating hazardous wastewater contaminants from industrial processes is currently a primary goal. Electroplating industry wastewater involves highly toxic cyanide (CN), heavy metal ions, oils and greases, organic solvents, and the complicated composition of effluents and may also contain biological oxygen demand (BOD), chemical oxygen demand (COD), SS, DS, TS, and turbidity. The availability of these metal ions in electroplating industry wastewater makes the water so toxic and corrosive. Because these heavy metals are harmful to living things, they must be removed to prevent them from being absorbed by plants, animals, and humans. As a result, exposure to electroplating wastewater can induce necrosis and nephritis in humans and lung cancer, digestive system cancer, anemia, hepatitis, and maxillary sinus cancer with prolonged exposure. For the safe discharge of electroplating industry effluents, appropriate wastewater treatment has to be provided. This article examines and assesses new approaches such as coagulation and flocculation, chemical precipitation, ion exchange, membrane filtration, adsorption, electrochemical treatment, and advanced oxidation process (AOP) for treating the electroplating industry wastewater. On the other hand, these physicochemical approaches have significant drawbacks, including a high initial investment and operating cost due to costly chemical reagents, the production of metal complexes sludge that needs additional treatment, and a long recovery process. At the same time, advanced techniques such as electrochemical treatment can remove various kinds of organic and inorganic contaminants such as BOD, COD, and heavy metals. The electrochemical treatment process has several advantages over traditional technologies, including complete removal of persistent organic pollutants, environmental friendliness, ease of integration with other conventional technologies, less sludge production, high separation, and shorter residence time. The effectiveness of the electrochemical treatment process depends on various parameters, including pH, electrode material, operation time, electrode gap, and current density. This review mainly emphasizes the removal of heavy metals and another pollutant such as CN from electroplating discharge. This paper will be helpful in the selection of efficient techniques for treatment based on the quantity and characteristics of the effluent produced.


Asunto(s)
Cáusticos , Complejos de Coordinación , Metales Pesados , Contaminantes Químicos del Agua , Purificación del Agua , Animales , Cianuros/química , Galvanoplastia/métodos , Humanos , Metales Pesados/análisis , Aceites , Contaminantes Orgánicos Persistentes , Aguas del Alcantarillado , Solventes , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Agua , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
13.
J Mater Sci Mater Med ; 32(9): 111, 2021 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-34453628

RESUMEN

This work is focused on integrating nanotechnology with bone tissue engineering (BTE) to fabricate a bilayer scaffold with enhanced biological, physical and mechanical properties, using polycaprolactone (PCL) and gelatin (Gt) as the base nanofibrous layer, followed by the deposition of a bioactive glass (BG) nanofibrous layer via the electrospinning technique. Electrospun scaffolds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. Surface area and porosity were evaluated using the nitrogen adsorption method and mercury intrusion porosimetry. Moreover, scaffold swelling rate, degradation rate and in vitro bioactivity were examined in simulated body fluid (SBF) for up to 14 days. Mechanical properties of the prepared scaffolds were evaluated. Cell cytotoxicity was assessed using MRC-5 cells. Analyses showed successful formation of bead-free uniform fibers and the incorporation of BG nanoparticles within fibers. The bilayer scaffold showed enhanced surface area and total pore volume in comparison to the composite single layer scaffold. Moreover, a hydroxyapatite-like layer with a Ca/P molar ratio of 1.4 was formed after 14 days of immersion in SBF. Furthermore, its swelling and degradation rates were significantly higher than those of pure PCL scaffold. The bilayer's tensile strength was four times higher than that of PCL/Gt scaffold with greatly enhanced elongation. Cytotoxicity test revealed the bilayer's biocompatibility. Overall analyses showed that the incorporation of BG within a bilayer scaffold enhances the scaffold's properties in comparison to those of a composite single layer scaffold, and offers potential avenues for development in the field of BTE.


Asunto(s)
Huesos/citología , Nanofibras/química , Ingeniería de Tejidos , Andamios del Tejido/química , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Líquidos Corporales/química , Huesos/efectos de los fármacos , Huesos/fisiología , Células Cultivadas , Cerámica/química , Cerámica/farmacología , Galvanoplastia/métodos , Gelatina/química , Gelatina/farmacología , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Poliésteres/química , Poliésteres/farmacología , Porosidad , Espectroscopía Infrarroja por Transformada de Fourier , Estrés Mecánico , Resistencia a la Tracción , Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos , Difracción de Rayos X
14.
Anal Biochem ; 612: 113956, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-32950496

RESUMEN

In this study we have developed a new aptasensor for cadmium (Cd2+) detection in water. Gold electrode surface has been chemically modified by electrochemical reduction of diazonium salt (CMA) with carboxylic acid outward from the surface. This was used for amino-modified cadmium aptamer immobilization through carbodiimide reaction. Chemical surface modification was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This latter was also used for Cd2+ detection. The aptasensor has exhibited a good linear relationship between the logarithm of the Cd2+ concentration and the impedance changes in the range from 10-3 to 10-9 M with a correlation R2 of 0.9954. A high sensitivity was obtained with a low limit of detection (LOD) of 2.75*10-10 M. Moreover, the developed aptasensor showed a high selectivity towards Cd2+ when compared to other interferences such as Hg2+, Pb2+ and Zn2+. The developed aptasensor presents a simple and sensitive approach for Cd2+detection in aqueous solutions with application for trace Cd2+ detection in spring water samples.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Cadmio/análisis , Técnicas Electroquímicas/métodos , Agua/análisis , Técnicas Biosensibles/métodos , Cationes/análisis , Compuestos de Diazonio/química , Espectroscopía Dieléctrica , Electrodos , Galvanoplastia/métodos , Oro/química , Límite de Detección , Reproducibilidad de los Resultados
15.
Molecules ; 26(1)2020 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-33379393

RESUMEN

Tubular-shaped layer electrodeposition from chitosan-hydroxyapatite colloidal solutions has found application in the field of regeneration or replacement of cylindrical tissues and organs, especially peripheral nerve tissue regeneration. Nevertheless, the quantitative and qualitative characterisation of this phenomenon has not been described. In this work, the colloidal systems are subjected to the action of an electric current initiated at different voltages. Parameters of the electrodeposition process (i.e., total charge exchanged, gas volume, and deposit thickness) are monitored over time. Deposit structures are investigated by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The value of voltage influences structural characteristics but not thickness of deposit for the process lasting at least 20 min. The calculated number of exchanged electrons for studied conditions suggests that the mechanism of deposit formation is governed not only by water electrolysis but also interactions between formed hydroxide ions and calcium ions coordinated by chitosan chains.


Asunto(s)
Quitosano/química , Durapatita/química , Galvanoplastia/métodos , Hidróxidos/química , Iones/química , Microscopía Electrónica de Rastreo/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Agua/química
16.
Chemosphere ; 261: 128157, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33113652

RESUMEN

Porous titanium-based PbO2 electrodes were successfully fabricated by pulse electrodeposition method. The primary pulse electrodeposition parameters, including pulse frequency (f), duty ratio (γ), average current density (Ja) and electrodeposition time (t) were considered in this study. An orthogonal experiment was designed based on those four factors and in three levels. SEM images and XRD results suggest that the surface morphology and structure of PbO2 electrodes could be easily changed by varying pulse electrodeposition parameters. Orthogonal analysis reveals that the increase of f and Ja could decrease the average grain size of PbO2 electrodes, which is conducive to create more active sites and promote the generation of hydroxide radicals. The electrochemical degradation of Azophloxine was carried out to evaluate the electrochemical oxidation performance of pulse electrodeposited electrodes. The results indicate that the influences of four factors can be ranked as follow: Ja >γ≈ t > f. The higher f, larger Ja and longer t could facilitate the optimization of the integrated electrochemical degradation performance of prepared PbO2 electrode. The accelerated life time is dominated by Ja and t, coincident with the average weight increase of ß-PbO2 layer. The optimal parameters of pulse electrodeposition turn out to be: f = 50 Hz, γ = 30%, Ja = 25 mA cm-2, t = 60 min. Together, the consequences of the experiments give assistance to uncover and roughly conclude the mechanism of pulse electrodeposition.


Asunto(s)
Galvanoplastia/métodos , Plomo/química , Modelos Teóricos , Óxidos/química , Titanio/química , Compuestos Azo/análisis , Electrodos , Naftalenosulfonatos/análisis , Oxidación-Reducción , Porosidad , Propiedades de Superficie , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
17.
J Vis Exp ; (163)2020 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-33044463

RESUMEN

Composite plating with particles embedded into the metal matrix can enhance the properties of the metal coating to make it more or less conductive, hard, durable, lubricated or fluorescent. However, it can be more challenging than metal plating, because the composite particles are either 1) not charged so they do not have a strong electrostatic attraction to the cathode, 2) are hygroscopic and are blocked by a hydration shell, or 3) too large to remain stagnate at the cathode while stirring. Here, we describe the details of a bathless plating method that involves anode and cathode nickel plates sandwiching an aqueous concentrated electrolyte paste containing large hygroscopic phosphorescent particles and a hydrophilic membrane. After applying a potential, the nickel metal is deposited around the stagnant phosphor particles, trapping them in the film. The composite coatings are characterized by optical microscopy for film roughness, thickness and composite surface loading. In addition, fluorescence spectroscopy can be used to quantify the illumination brightness of these films to assess the effects of various current densities, coating duration and phosphor loading.


Asunto(s)
Galvanoplastia/métodos , Conductividad Eléctrica , Electroquímica , Electrodos , Procesamiento de Imagen Asistido por Computador , Níquel/química , Espectrometría de Fluorescencia , Humectabilidad
18.
J Chromatogr A ; 1628: 461486, 2020 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-32822970

RESUMEN

In this work, an inexpensive, fast, and selective ionic liquid modified graphene oxide (GO-IL) was synthesized and electrochemically deposited on the inner surface of a stainless-steel tube. Then, it was applied for circulated headspace in-tube solid-phase microextraction (CHS-IT-SPME) of naphthalene from honey samples. Next, the coated tube was replaced with the sample loop of a six-port injection valve for on-line desorption and further HPLC-UV analysis of naphthalene. The sorbent was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDX). Different parameters affecting the procedure efficiency, including extraction temperature, extraction time, salt concentration, and sample volume were optimized by central composite design and response surface methodology. Under the optimum conditions, the calibration curve was linear within the range of 0.3-200 ng mL-1, with a regression coefficient of 0.9972. The limits of detection (LOD) and quantification (LOQ) were found to be 0.1 ng mL-1 and 0.3 ng mL-1, respectively. Intra-day and inter-day RSDs% for three replicate measurements of naphthalene at the concentration of 10 ng mL-1 were obtained 3.9% and 5.0%, respectively. Also, good tube-to-tube reproducibility of 5.3% was achieved. Finally, the method was successfully applied for measuring trace amounts of naphthalene in honey samples. Relative recoveries were calculated within the range of 90.0-106.5%, indicating excellent efficiency of the proposed method.


Asunto(s)
Cromatografía Liquida/métodos , Galvanoplastia/métodos , Grafito/química , Miel/análisis , Líquidos Iónicos/química , Naftalenos/aislamiento & purificación , Sistemas en Línea , Microextracción en Fase Sólida/métodos , Cromatografía Líquida de Alta Presión , Límite de Detección , Nanoestructuras/química , Nanoestructuras/ultraestructura , Reproducibilidad de los Resultados
19.
Chemosphere ; 259: 127488, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32640376

RESUMEN

A Ce-doped Ti/PbO2 electrode was prepared in a deposition solution containing Ce3+ and Pb2+ ions by electrodeposition, and the surface morphology, crystal structure and elemental states were characterized by SEM, XRD and XPS. The electrode was used to investigate the simultaneous degradation of three phthalate esters (PAEs), i.e., dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP) in synthetic wastewaters. The results showed that the electrode exhibited excellent electrocatalytic activity and good reusability and stability, and the removal efficiencies of 5 mg L-1 DBP, DMP and DEP in 0.05 M Na2SO4 (pH 7) reached 98.2%, 95.8% and 81.1% at current density of 25 mA cm-2 after 10 h degradation, respectively. The degradation processes followed pseudo first-order kinetic model very well, and the observed rate constants of DBP, DEP and DMP were 0.42, 0.40 and 0.29 h-1, respectively. The energy consumption in three PAEs degradation was also assessed. The main degradation products of the three PAEs were identified by using liquid chromatography-tandem mass spectrometry, and the possible degradation pathways mainly included dealkylation, hydroxyl addition, decarboxylation and benzene ring cleavage. This work is a promising candidate for efficient treatment of multiple PAEs in wastewater and protection of the aquatic ecological environment.


Asunto(s)
Cerio/química , Galvanoplastia/métodos , Restauración y Remediación Ambiental/métodos , Ácidos Ftálicos/química , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Dibutil Ftalato/química , Electrodos , Ésteres/química , Plomo/química , Óxidos/química , Titanio/química
20.
J Mater Sci Mater Med ; 31(8): 69, 2020 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-32705408

RESUMEN

In recent years, the engineering of biomimetic cellular microenvironments has emerged as a top priority for regenerative medicine, being the in vitro recreation of the arcade-like cartilaginous tissue one of the most critical challenges due to the notorious absence of cost- and time-efficient microfabrication techniques capable of building 3D fibrous scaffolds with precise anisotropic properties. Taking this into account, we suggest a feasible and accurate methodology that uses a sequential adaptation of an electrospinning-electrospraying set up to construct a hierarchical system comprising both polycaprolactone (PCL) fibres and polyethylene glycol sacrificial microparticles. After porogen leaching, the bi-layered PCL scaffold was capable of presenting not only a depth-dependent fibre orientation similar to natural cartilage, but also mechanical features and porosity proficient to encourage an enhanced cell response. In fact, cell viability studies confirmed the biocompatibility of the scaffold and its ability to guarantee suitable cell adhesion, proliferation and migration throughout the 3D anisotropic fibrous network during 21 days of culture. Additionally, likewise the hierarchical relationship between chondrocytes and their extracellular matrix, the reported PCL scaffold was able to induce depth-dependent cell-material interactions responsible for promoting a spatial modulation of the morphology, alignment and density of the cells in vitro.


Asunto(s)
Cartílago/citología , Ingeniería de Tejidos , Andamios del Tejido/química , Animales , Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Biomimética , Cartílago/efectos de los fármacos , Cartílago/fisiología , Bovinos , Supervivencia Celular , Células Cultivadas , Condrocitos/citología , Condrocitos/efectos de los fármacos , Condrocitos/fisiología , Materiales Biocompatibles Revestidos/síntesis química , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Galvanoplastia/métodos , Matriz Extracelular/química , Matriz Extracelular/efectos de los fármacos , Ensayo de Materiales , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/fisiología , Microtecnología/métodos , Poliésteres/química , Poliésteres/farmacología , Polietilenglicoles/química , Polietilenglicoles/farmacología , Medicina Regenerativa/instrumentación , Medicina Regenerativa/métodos , Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos
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