Black Nanocomposites Research Articles

Low-cost screen-printed electrodes based on electrochemically reduced graphene oxide-carbon black nanocomposites for dopamine, epinephrine and paracetamol detection

A green approach for the preparation of carbon black (CB) and electrochemically reduced graphene oxide composite (ERGO) is described based on screen printed carbon electrodes (SPCEs) fabricated on poly(ethylene terephthalate) (PET) as electrochemical sensors. This approach leads to a heterogeneous hydrophilic surface with high concentration of defect sites according to scanning electron microscopy, contact angle and Raman spectroscopy measurements. The SPCE/CB-ERGO sensor was tested with dopamine (DA), epinephrine (EP) and paracetamol (PCM), exhibiting an enhanced electrocatalytic performance compared to the bare SPCE. It displayed a wider linear range, lower limit of detection and a remarkably higher analytical sensitivity, viz. 1.5, 0.13 and 0.028 A L mol−1 for DA, EP and PCM, respectively, being also capable of simultaneous determination of the three analytes. Such high performance is demonstration that SPCE/CB-ERGO may serve as generic platform for cost-effective flexible electrochemical sensors.

Tuning the Composition and Structure of Amorphous Molybdenum Sulfide/Carbon Black Nanocomposites by Radiation Technique for Highly Efficient Hydrogen Evolution

Amorphous molybdenum sulfide/carbon black (MoSx/C) nanocomposites are synthesized by a facile one-step γ-ray radiation induced reduction process. Amorphous MoSx shows better intrinsic activity than crystalline MoS2. And the composition and amorphous structure of MoSx could be expediently tuned by absorbed dose for excellent catalytic activity. Meanwhile, the addition of carbon black leads to a significant decrease of charge transfer resistance and increase of active sites of MoSx/C composite. Consequently, MoSx/C nanocomposite shows Pt-like catalytic activity towards hydrogen evolution reaction (HER), which requires an onset over potential of 40 mV and over potential of 76 mV to achieve a current density of 10 mA cm−2, and the corresponding Tafel slope is 48 mV decade−1. After 6000 CV cycles, the catalytic activity of MoSx/C shows no obvious decrease. However, when platinum (Pt) foil is used as counter electrode, MoSx/C composite show better catalytic activity abnormally after long-term cycling tests. The dissolution of Pt was observed in HER and the Pt dissolution mechanism is elucidated by further analyzing the surface composition of after-cycling electrodes, which offers highly valuable guidelines for using Pt electrode in HER.

Acetylene black coated V2O5 nanocomposite with stable cyclability for lithium-ion batteries cathode

Owing to the excellent power density, energy storage capability, and rechargeable nature, lithium-ion batteries are being used in laptops, vehicles, home electronics and large-scale industrial instruments, and thus governing the market of portable electronics. Here, we present the electrochemical performance of the V2O5/acetylene black (V2O5/C) nanocomposite, used as a cathode material in lithium-ion batteries, prepared by a facile chemical synthesis route. The nanocomposite shows an outstanding electrochemical performance with a discharge capacity of 361 mAh g−1 during 1st cycle and retains a capacity of 254 mAh g−1 after 100 cycles, at a step rate of 0.1 C. Further, electrochemical impedance spectroscopy was employed to examine the reaction kinetics before and after cycling and the Li+-diffusion coefficient was calculated to be 1.67 × 10−12 and 6.13 × 10−15 cm2 s−1, respectively. The enhanced electrochemical performance of V2O5/C nanocomposite can be ascribed to the synergistic effect of nanosized V2O5 and conductive acetylene black, which could shorten diffusion pathway, play a role of efficient charge carrier and make the electrode have better electronic/ionic conductivity and lower resistance. Hence, V2O5/C nanocomposite could be utilised as promising cathode material for lithium-ion batteries because of its stable electrochemical performance.

Dimensionally integrated α-MnO2/Carbon black binary complex as platinum free counter electrode for dye sensitized solar cell

Abstract α-MnO 2 /carbon black nanocomposites were synthesized using hydrothermal method. The α-MnO 2 /carbon black (CB) nanocomposites was fabricated as counter electrode (CE) for Platinum (Pt) free DSSC. Morphological study was carried out using scanning electron microscope (SEM) and transmission electron microscope (TEM). FTIR, Raman and XPS study substantiate well about the formation of nanocomposites. Brunauer-Emmett-Teller (BET) isotherm reveals the embedment of CB which enhances surface area of α-MnO 2 /CB nanocomposites. α-MnO 2 /CB nanocomposites CE shows very good electrochemical and electrocatalytic activity. Their respective study was carried out using electrochemical impedance spectroscopy and cyclic voltammetry. The better electrocatalytic activity and low charge transfer resistance (R ct ) of α-MnO 2 /CB nanocomposites as CE, imparts an improvement of photo conversion efficiency. The conversion efficiency (η) of 4.29% was achieved using α-MnO 2 -120/CB as DSSC CE which is closely comparable to Platinum as CE.

Modeling microwave dielectric properties of polymer composites using the interphase approach

The electrical properties of heterogeneous materials are closely related to the composition of its constituents. Several theoretical approaches have been developed to predict the complex permittivity of composites materials, such as the mixture laws and the effective medium theories. However, these laws fail to interpret experimental data at high concentrations of filler, because the morphological parameters such as particle size, their distribution, and mostly the interphase region between the components are not taken into account. A new model for predicting the complex permittivity of composite materials is presented, taking into account the interaction between the filler and the matrix. We report a study on the dielectric properties of the epoxy polymer/carbon black nanocomposites, with different concentrations of the dispersed conducting particles, at 35 GHz, using the interphase model. The experimental results of the complex permittivity are compared to those obtained by the proposed theoretical model.

Properties of biodegradable poly(butylene succinate) (PBS) composites with carbon black

Biodegradable poly(butylene succinate)/carbon black (PBS/CB) nanocomposite was prepared by melt compounding and the amount of CB loading was 3 wt %. The PBS/CB nanocomposite exhibited not only a good dispersion of aggregates of CB in the PBS matrix, but also an improvement in mechanical and electrical properties as well. The nonisothermal crystallization behavior and crystal structure of neat PBS and its nanocomposite were also studied by differential scanning calorimetry and wide angle X-ray diffraction in detail. The crystal morphology is observed by polarized optical microscopy. The Avrami equation and the Mo equation were employed to describe the nonisothermal crystallization kinetics. The Mo equation was found to be more suitable to predict the whole nonisothermal crystallization process for both neat PBS and its nanocomposite. It was concluded that the addition of CB retarded the crystallization rate compared with that of neat PBS at the same cooling rate, which can be attributed to restricting effect of CB on the segmental motions of the polymer chains. Moreover, the incorporation of the CB particles does not modify the crystal structure of PBS.

Viscoelastic and electrical behavior of poly(methyl methacrylate)/carbon black composites prior to and after annealing

In this letter, both the viscoelastic and electrical properties of poly(methyl methacrylate)/carbon black (PMMA/CB) nanocomposites with different CB concentrations prior to and after annealing were investigated. The linear steady-state recoverable compliance of pure PMMA is independent of annealing as it reflects only polymer-polymer interactions. While the conductivity of PMMA/CB nanocomposites increases gradually with annealing, and the viscoelastic properties show different regions of response depending on the CB concentration. At CB contents below the percolation threshold the recoverable compliances increase after annealing, whereas the reverse trend is found at CB contents above the percolation threshold. This behavior is related to the interplay between network formation and particle-particle interactions.

Atomic layer deposition of ZnO on carbon black as nanostructured anode materials for high-performance lithium-ion batteries

Although zinc oxide (ZnO), a low-cost and naturally abundant material, has a high theoretical specific capacity of 987 mA h g-1 for hosting lithium ions, its application as an anode material has been hindered by its rapid capacity fading, mainly due to a large volume change (around 228%) upon repeated charge-discharge cycles. Herein, using carbon black (CB) powder as a support, ZnO-carbon black (denoted as ZnO-CB) nanocomposites were successfully fabricated using the atomic layer deposition (ALD) method. This method was able to produce strong interfacial molecular bindings between ZnO nanoclusters and the carbon surface that provide stable and robust electrical contact during lithiation and delithiation processes, as well as ZnO nanoclusters rich in oxygen vacancies (OVs) for faster Li-ion transport. Overall, the nanocomposites were able to deliver a high discharge specific capacity of 2096 mA h g-1ZnO at 100 mA g-1 and stable cyclic stability with a specific capacity of 1026 mA h g-1ZnO maintained after 500 cycles. The composites also have excellent rate capability, and a reversible capacity at a high 1080 mA h g-1ZnO at 2000 mA g-1. The facile but unique synthesis method demonstrated in this work for producing nanostructures rich in OVs and nanocomposites with strong coupling via interfacial molecular bindings could be extended to the synthesis of other oxide based anode materials and therefore could have general significance for developing high energy density lithium ion batteries.

Multiscale metrologies for process optimization of carbon nanotube polymer composites

Carbon nanotube (CNT) polymer nanocomposites are attractive multifunctional materials with a growing range of commercial applications. With the increasing demand for these materials, it is imperative to develop and validate methods for on-line quality control and process monitoring during production. In this work, a novel combination of characterization techniques is utilized, that facilitates the non-invasive assessment of CNT dispersion in epoxy produced by the scalable process of calendering. First, the structural parameters of these nanocomposites are evaluated across multiple length scales (10−10 m to 10−3 m) using scanning gallium-ion microscopy, transmission electron microscopy and small-angle neutron scattering. Then, a non-contact resonant microwave cavity perturbation (RCP) technique is employed to accurately measure the AC electrical conductivity of the nanocomposites. Quantitative correlations between the conductivity and structural parameters find the RCP measurements to be sensitive to CNT mass fraction, spatial organization and, therefore, the processing parameters. These results, and the non-contact nature and speed of RCP measurements identify this technique as being ideally suited for quality control of CNT nanocomposites in a nanomanufacturing environment. When validated by the multiscale characterization suite, RCP may be broadly applicable in the production of hybrid functional materials, such as graphene, gold nanorod, and carbon black nanocomposites.

Fe3O4–carbon black nanocomposite as a highly efficient counter electrode material for dye-sensitized solar cell

Iron oxide–carbon black (Fe3O4–CB) nanocomposite has been proposed as a cost–effective alternative counter electrode (CE) to the conventional Pt in a dye sensitized solar cell (DSSC). The Fe3O4–CB nanocomposite at three different weight ratio (1:1, 1:2 and 2:1) was prepared by a simple solution mixing process and the material was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopy techniques. The performance of the three Fe3O4–CB nanocomposite CEs was assessed with respect to Fe3O4, CB and Pt in a conventional DSSC consisting of N719 dye sensitized TiO2 (P25) photoanode in contact with an electrolyte containing the I−/I3− redox couple. The electrocatalytic activities of the various CEs towards triiodide (I3−) reduction were analyzed by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization analysis. The photocurrent voltage (J–V) characteristics of the DSSCs assembled with various counter electrodes were assessed at a light intensity of 80mWcm−2. The DSSC assembled with Fe3O4–CB nanocomposite (1:2) CE showed the best photovoltaic performance in terms of a high power conversion efficiency of 6.1% which is superior to that of sputtered Pt (4.1%). The simple preparation, excellent electrocatalytic activity and low-cost nature allow the Fe3O4–CB nanocomposite to be a promising alternative CE to Pt for use in DSSCs.

Comparative study of effect of corrosion on mild steel with waterborne polyurethane dispersion containing graphene oxide versus carbon black nanocomposites

Recently developed strategies for graphene oxide and carbon black nanocomposites have enabled production of robust waterborne polymer nanocomposites with enhanced nanoparticle dispersion and barrier protection performance. In this article, we have presented processing, morphology and properties of waterborne polyurethane (WPU) reinforced with synthetic polymer of polyvinyl alcohol (PVA) modified GO/zinc oxide (GO/ZnO) and functionalized carbon black/ZnO (CB/ZnO) nanocomposites. The incorporation of nanofillers into PVA matrix offers the opportunity to develop nanocomposites with enhanced anchoring effect and barrier protection properties. For the first time, we have compared CB and GO nanocomposites for its corrosion protection, latter was found to be superior in resistance to corrosion than former. The prepared nanocomposites were characterized by XRD, FESEM, XPS, Raman spectroscopy and contact angle measurements. The corrosion resistant properties were investigated by potentio-dynamic polarization studies using Tafel parameters and electrochemical impedance spectroscopy. Incorporation of 0.1–0.3 wt% of nanofillers in WPU dispersion has produced effective nanocomposite, with a resistance to corrosion on mild steel. This observation is in good qualitative agreement with the surface wettability and dispersion level of the nanocomposite in waterborne medium. This study has showed a new approach for synthetic polymer PVA anchored GO/ZnO and CB/ZnO which acts as filler in waterborne medium enhances the anti-settling behavior and resistance to corrosion. Moreover, by comparing these results reveal that, PVA anchored GO supported nano ZnO is higher in performance than PVA anchored CB supported nano ZnO in WPU dispersion.

Energy storage in symmetric and asymmetric supercapacitors based in carbon cloth/polyaniline-carbon black nanocomposites

Fil: Bavio, Marcela Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Tandil. Centro de Investigaciones En Fisica E Ingenieria del Centro de la Provincia de Buenos Aires; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ingenieria Olavarria. Departamento de Electromecanica. Grupo INTELYMEC; Argentina

Preparation of UHMWPE/carbon black nanocomposites by in situ Ziegler–Natta catalyst and investigation of product thermo-mechanical properties

A new bi-supported Ziegler–Natta catalyst was prepared successfully by supporting TiCl4 on the carbon black (CB) and magnesium dichloride. Then, this catalyst was used to prepare ultrahigh molecular weight polyethylene (UHMWPE) nanocomposites via in situ polymerization. The effects of difference molar ratios of triisobutylaluminum as activator to TiCl4, polymerization temperature, pressure of monomer and polymerization time on productivity of the catalyst were studied. The maximum activity was obtained at [Al]/[Ti] = 121:1. Increasing monomer pressure raised catalyst activity. Increasing temperature to 60 °C increased the polymerization yield; however, the higher temperature decreased the productivity of the catalyst. Scanning electron microscopic images showed that homogeneous dispersion of CB nanoparticles in the polymeric matrix was achieved without any agglomeration of CB. The crystallization behavior was evaluated using differential scanning calorimeter. The results showed that the crystallinity degree of UHMWPE slightly increased with increasing of CB, indicating that the CB acted as hindrance and nucleating agent. Furthermore, with introducing CB to polymeric matrix up to 1.6 wt%, the melting temperature and crystallization temperatures were slightly increased. The thermogravimetric analysis showed that incorporation of CB has improved thermal stability of polymeric matrix compared to pure UHMWPE. Viscoelastic properties were also investigated using dynamic mechanical thermal analysis. Obtained results showed that with introducing CB, the storage and loss modulus were improved especially at low temperatures and the glass transition temperature was slightly altered. Significant incensement in mechanical properties of the polyethylene was observed by adding nanofiller, in the other words, the presence of CB considerably improved tensile strength, Young’s modulus, and yield stress.

Synergistic effect of zero-dimensional spherical carbon nanoparticles and one-dimensional carbon nanotubes on properties of cement-based ceramic matrix: microstructural perspectives and crystallization investigations

In the present investigation, hybrid effect of spherical carbon nanoparticles and carbon nanotubes as zero- and one-dimensional entities, respectively (synthesized by novel CVD route), on properties of cement ceramic matrix was studied. Ceramic matrix composites were fabricated using different dosages (% by wt. of cement) of as-synthesized nanoadditive (labeled as rCNTs) and tested for their resistance to compression at increasing hydration curing times of 7, 14, and 28 days. Evolution of different inorganic crystalline phases in composites was examined using X-ray diffraction (XRD). Improvement in mechanical behavior of composites was explained on the basis of microstructural observations using field emission scanning electron microscopy (FE-SEM). Electrical behavior was evaluated using four-probe method and it was observed that addition of nanoadditive had a semiconducting influence on ceramic matrix composites. Thermal behavior of composites was investigated using thermogravimetric analysis (TGA) and compared with that of unreinforced counterpart. All the properties of rCNT composites were compared with carbon black (pCB) cement mortar nanocomposites. Obtained results indicated a maximum improvement of 13.5% in strength in case of 0.125% rCNT cement mortar composite. Electrical and thermal properties were improved with incorporation of rCNTs indicating significant potential for the practical application of low-cost novel rCNT in the preparation of cement-based materials of high strength and smart functionality.

Ratiometric electrochemical sensor for effective and reliable detection of ascorbic acid in living brains.

The in vivo detection of ascorbic acid (AA), one of the physiologically important cerebral neurochemicals, is critical to probe and understand brain functions. Electrochemical sensors are convenient for AA detection. However, conventional electrochemical sensors usually suffer from several challenges, such as sluggish electron transfer kinetics for AA oxidation and poor reproducibility. To address these challenges, here we report ratiometric electrochemical sensors for effective and reliable detection of AA in living brains. The sensors were constructed by immobilizing preassembled thionine/Ketjen black (KB) nanocomposites onto glassy carbon (GC) electrodes or carbon fiber microelectrodes (CFMEs). The KB in the rationally functionalized nanocomposites efficiently facilitated AA oxidation at a relatively negative potential (∼-0.14 V) without particular physical or chemical pretreatment, forming the basis of selective measurement of AA. With a well-defined and reversible pair of redox wave at -0.22 V, the assembled thionine acted as an internal reference to substantially alleviate the lab-to-lab, person-to-person, and electrode-to-electrode variations. The in vitro experiments demonstrated that the sensors exhibited extremely high reproducibility and stability toward selective measurement of AA. More, with operational simplicity and robustness in analytical performance, the designed sensors were successfully applied to in vivo effectively, selectively, and reliably monitor the dynamic change of cerebral AA associated with pathological processes (i.e., salicylate-induced tinnitus as the model) in living rats' brains. This study not only offers a new strategy for construction of ratiometric electrochemical sensors but also opens a new way for selective and reliable detection of neurochemicals for probing brain functions.

Prediction of the DC electrical conductivity of carbon black filled polymer composites

Different DC electrical conductivity models have been proposed to predict the properties of composite materials. Among these, the Mamunya model gives a good agreement with experimental data for different carbon black nanocomposites below the threshold concentration. In this paper, we extend the study using the Scarisbrick model. However, the percolation phenomenon is not observed and a modified model which takes into account some parameters, such as the aspect ratio and surface area to volume ratio of fillers, is used to accurately justify the conductive network formation. The modified Scarisbrick model shows clearly the percolation phenomenon and gives satisfactory results for the series samples which present high percolation threshold.

Enhanced thermoelectric performance of highly conductive poly(3,4-ethylenedioxythiophene)/carbon black nanocomposites for energy harvesting

The thermoelectric performance of para-methylbenzenesulfonate (p-MeBzs) doped highly conductive poly(3,4-ethylenedioxythiophene) (PEDOT) can be improved by the use of carbon black fillers. Thermoelectric nanocomposites were prepared via chemical polymerization. Dodecylbenzenesulfonic acid (DBSA) was introduced before polymerization to act simultaneously as a surfactant for formation of micelles of carbon black and as a doping agent. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize the morphology of PEDOT coated carbon black and PEDOT. Electrical conductivity of the composites improved with increase in weight percentage of carbon black from 0% to 30%. Extended chain conformations and increase in electron delocalization reduces the carrier hopping barriers. These contribute to the enhancement of charge carrier mobility. Although electrical conductivity is directly proportional to the increase in the filler content, Seebeck coefficient is more or less constant. Relatively small changes of thermal conductivity can be attributed to the phonon scattering effect in both the carbon black and the thermally insulating PEDOT layers. This study reports that the power factor of the composite was estimated to be 0.993μW/mK2 for 10wt% filler content and was more than 1.7 times higher than that for pure PEDOT, and the maximum figure of merit (ZT) value was 0.0012 at room temperature.

Enhancement of electroactivity of platinum–tungsten trioxide nanocomposites with NaOH-treated carbon support toward methanol oxidation reaction

Platinum–tungsten trioxide nanocomposite electrocatalysts on carbon black support (Pt–WO3/C) are synthesized and their electrocatalytic performances toward methanol oxidation reaction (MOR) are investigated in this study. Tungsten trioxide, which derived from the hydrolysis of tungsten hexachloride (WCl6) in dimethylformamide (DMF) solution, is firstly deposited onto pristine or NaOH-treated Vulcan XC-72 carbon black (C or Cs) support to obtain tungsten trioxide/carbon black (WO3/C or WO3/Cs) nanocomposites, and then Pt nanoparticles are decorated onto these nanocomposites by polyol method to obtain Pt–WO3/C or Pt–WO3/Cs electrocatalysts. XRD and TEM characterizations are performed to examine the WO3 structures and the size distributions of the Pt nanoparticles. The effects of WO3 loading, annealing temperature and the NaOH-treatment of carbon black support on MOR mass activity and CO-tolerance ability of the electrocatalysts are investigated. The electrocatalyst (PtW(0.08)Cs200) with the WO3/Cs nanocomposite derived from a DMF solution containing 0.08M WCl6, using NaOH-treated XC-72 carbon black as the support and annealed at 200°C, achieves the highest MOR activity among all the electrocatalysts synthesized in this study. The MOR performances of PtW(0.08)Cs200 is superior to that of the commercial E-TEK Pt(20wt%)/C and E-TEK PtRu(20wt%)/C electrocatalysts under the same test conditions.

New insights into the elasticity and multi-level relaxation of filler network with studies on the rheology of isotactic polypropylene/carbon black nanocomposite

The elasticity and multi-level relaxation behavior of filler network in isotactic polypropylene/carbon black nanocomposites were systematically studied, which was instructive for the development and application of viscoelastic materials.

Design of mass-controllable NiCo2S4/Ketjen Black nanocomposite electrodes for high performance supercapacitors

NiCo2S4/Ketjen Black nanocomposites have been successfully fabricated on nickel foam by a facile two-step solution-based method. The Ni1K0.25 electrode has a competitive areal specific capacitance, good rate capacitance and excellent cycling stability.