Carbon Black Mixture Research Articles

Binary Network of Conductive Elastic Polymer Constraining Nanosilicon for a High-Performance Lithium-Ion Battery.

Silicon-based anodes are attracting more interest in both science and industry due to their high energy density. However, the traditional polymeric binder and carbon additive mixture cannot successfully accommodate the huge volume change and maintain good conductivity when cycling. Herein, we report a multifunctional polymeric binder (PPTU) synthesized by the cross-linking of conducting polymer (PEDOT:PSS) and stretchable polymer poly(ether-thioureas) (PETU). The multifunctional polymeric binder could be curved on the surfaces of nanosilicon particles, forming an interweaving continuous three-dimensional network, which is beneficial to electron transfer and the mechanical stability. Furthermore, the binder is elastic and adhesive, and which can accommodate the huge volume change of silicon to keep its integrity. Utilizing this multifunctional polymeric binder instead of commercial poly(acrylic acid) binder and carbon black mixtures, the nanosilicon anode demonstrates enhanced cycling stability (2081 mAhg-1 after 300 cycles) and rate performance (908 mAhg-1 at 8 Ag-1). The multifunctional polymeric binder has high conductivity, elasticity, and self-healing properties is a promising binder to promote progress toward a high performance lithium-ion battery.

In-situ graphene platelets formation and its suppression during reactive spark plasma sintering of boron carbide/titanium diboride composites

Boron carbide composites with 10 vol.% TiB2 were prepared by reactive sintering of B4C, TiO2, and carbon black powder mixture at the temperature of 1800 °C, under a pressure of 70 MPa in a vacuum. The combined effects of electric current and in-situ reactions led to a significant overheating of the central part of the sample, while no overheating was observed for hot press and non-reactive SPS processes. A lower electrical resistivity of TiB2 produced a significant Joule heating of boron carbide, leading to its partial decomposition to form gaseous boron and graphene platelets. Homogenous, fully dense and graphene-free samples were obtained when employing an insulating Al2O3 paper during reactive SPS. A short dwell time (30 s after a degassing step of 6 min) and the uniform distribution of fine TiB2 grains were the main advantages of isolated SPS over the reactive hot press and SPS processes, respectively.

Carbon reduction of Ti3AlC2 phase for TiC nanosheet production

ABSTRACT In this study, we investigated the formation of TiC nanosheets from carbon black and Ti3AlC2 mixtures in NaCl-KCl eutectic salt. The effects of raw material ratio, molten salt ratio, and heating temperature on TiC formation were studied in detail. Results show that carbon black may enhance the decomposition of amounts of Ti3AlC2 at 1,100°C by heat treatment without salt addition, while molten salt plays key roles in the total decomposition of Ti3AlC2 and the formation of TiC nanosheets at 1,000°C. Higher heating temperature and excess carbon black benefits the synthesis of high content TiC. The as-synthesized TiC nanosheets are approximately 15 nm thick and 80–220 nm long. We propose a possible reaction mechanism that governs TiC formation in molten salts and explain the observations based on kinetic considerations.

Modification of rubber compositions by carbon nanotubes

The description of the method developed by the authors of modification of the carbon black (CB) reinforced rubber composition by addition multiwall carbon nanotubes (CNTs) into its composition is presented. The process includes the pre-formation of a mixture of CB with CNT by their joint treatment in a liquid, which ensures deagglomeration of CNTs and uniform distribution of CNTs and CB among themselves, subsequent drying, loosening and addition into the rubber composition with stirring. The amount and composition of hybrid nanofiller (CB and CNTs), as well as the method of CNTs inclusion: CB addition, CB substitution or its partial substitution is determined by a calculation that takes into account the ratio between the specific surface of CB and CNTs and the average particle size. Comparison of the predicted values of CNTs and CB with experimental data for rubber compositions with optimal characteristics based on both natural and synthetic rubbers shows the high efficiency of the applied method.

3D-structured organic-inorganic hybrid solid-electrolyte-interface layers for Lithium metal anode

The solid-electrolyte-interface (SEI) layer plays a key role in lithium ion batteries, obstructing undesirable electrolyte decomposition by selective lithium ion transport into the active electrode materials. However, lithium metal anodes (LMAs) suffer from infinite volume expansion during metal deposition/stripping cycles, where the typical 2D SEI layers have a limitation in covering three-dimensionally growing lithium metal. In this study, 3D-structured organic-inorganic hybrid SEI (3D-hyb-SEI) layers were prepared using a sulfur copolymer (SCP)- poly(sulfur-random-1,3-diisopropenylbenzene) (poly (S-r-DIB)), and carbon black (CB) mixtures. Sulfur atoms of poly(S-r-DIB) form inorganic Li2S by conversion reactions with lithium ions, and the remaining DIB molecules react with the electrolyte to form organic SEI compounds. The 3D-hyb-SEI layers guide stable and durable lithium metal deposition/dissolution cycles by protecting the 3D-structured LMA, as evident from the significantly stable and long-term cycle life over 1,000 cycles, with an average Coulombic efficiency value of ~99.0%. The practicability of the 3D-hyb-SEI layers was demonstrated by a full-cell test with a commercial NCM622 cathode, whereby high energy and power densities of ~540 Wh kgelectrode−1 and ~2,840 W kgelecrode−1, respectively, were achieved with high cycling stability.

Determination of Three Typical Metabolites of Pyrethroid Pesticides in Tea Using a Modified QuEChERS Sample Preparation by Ultra-High Performance Liquid Chromatography Tandem Mass Spectrometry.

Pyrethroid pesticides are widely used on tea plants, and their residues of high frequency and concentration have received great attention. Until recently, the residues of typical metabolites of pyrethroid pesticides in tea were unknown. Herein, a modified “quick, easy, cheap, effective, rugged and safe” (QuEChERS) method for the determination of three typical metabolites of pyrethroid pesticides in tea, using ultra performance liquid chromatography tandem mass spectrometry, was developed. The mixture of florisil, octadecylsilane, and graphite carbon black was employed as modified QuEChERS adsorbents. A Kinetex C18 column achieved good separation and chromatographic peaks of all analytes. The calibration curves of 3-phenoxybenzoic acid (3-PBA) and 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA) were linear in the range of 0.1–50 ng mL−1 (determination coefficient R2 higher than 0.999), and that of cis-3-(2-chloro-3,3,3-trifluoroprop-1-en-1-yl)-2,2-dimethylcyclopropanecarboxylic acid (TFA) was in the range of 1–100 ng mL−1 (R2 higher than 0.998). The method was validated and recoveries ranged from 83.0% to 117.3%. Intra- and inter-day precisions were lower than or equal to 13.2%. The limits of quantification of 3-PBA, 4-F-3-PBA, and TFA were 5, 2, and 10 μg kg−1, respectively. A total of 22 tea samples were monitored using this method, and 3-PBA and TFA were found in two green tea samples.

Testing the role of electrode materials on the electro-Fenton and photoelectro-Fenton degradation of clopyralid

This work studies the effect of the anode and cathode materials on the degradation of the herbicide clopyralid. Different electrochemical advanced oxidation processes (EAOPs), including electrochemical oxidation with electrogenerated hydrogen peroxide (EO-H2O2), electro-Fenton (EF), and photoelectro-Fenton (PEF) were carried out. The first experiments were focused on the effect of the cathode, where the use of the hydrophobic carbon felt modified by the deposition of carbon black & PTFE mixture (MCF) improves the H2O2 production in comparison to a conventional carbon felt (CF), regardless of the anode material employed. On the other hand, a laser-made Ti/Ru0.3Ti0.7O2 mixed metal oxide (MMO) and a commercial boron-doped diamond (BDD) were compared as anodes. Results obtained point out that the MMO anode promotes the accumulation of this oxidant (H2O2) in bulk. Once characterized by the production of hydrogen peroxide, the second part of this study focused on the degradation of clopyralid with the MCF cathode with different EAOPs. Results demonstrate that clopyralid fastly degrades in the sequence EO-H2O2 < EF < PEF, and almost complete mineralization occurs for EF and PEF employing MMO or BDD as the anode. Synergy effect study shows that irradiation of 9 W UVC produces a positive synergistic effect of 81.7% and 41.55% (for the PEF-MMO and PEF-BDD, respectively), ascribed to the additional removal of aromatic intermediates by the UVC and the activation of H2O2. At the end of the treatment, mineralization of the herbicide was attained at 1.22 kW h (g−1 TOC). Finally, considering the lower cost of the prepared MMO, these findings demonstrate the potentiality of using modified carbon felt combined with the laser-made Ti/Ru0.3Ti0.7O2 anode for the treatment of polluted waters.

Combustion of Titanium-Carbon Black High-Energy Ball-Milled Mixtures in Nitrogen: Formation of Titanium Carbonitrides at Atmospheric Pressure.

In this work, titanium carbonitrides were synthesized by self-propagating high-temperature synthesis (SHS) in nitrogen. For the first time, the synthesis of titanium carbonitrides by combustion was realized in nitrogen at atmospheric pressure. The synthesis was carried out by subjecting high-energy ball-milled titanium–carbon black powder mixtures to combustion in a nitrogen atmosphere. The influence of the ball milling time on the phase composition of the products of SHS conducted in the Ti+0.3C reaction mixture was studied. It was found that the titanium–carbon black mixtures need to be milled for a certain period of time for the combustion synthesis to yield a single-phase carbonitride product.

Printed Resistive Sensor Array Combined with a Flexible Substrate for Ethanol and Methane Detection

In this research, we combined printed electrodes and a flexible substrate to develop a low-cost, resistive, gas sensor with small energy consumption. The ability to measure a gas is derived from an analysis of the resistance change resulting from gas molecules adsorbed by a polymer. With the sensor array coated with various polymers, we can identify the gas type and its concentration. Eight combinations of electrode with different width and gap were designed. The electrodes were printed on PET substrates with silver ink. Sensing material developed with mixture of Polyvinylpyrrolidone (PNVP), Carbon Black (CB) and solvent ethylene glycol (EG) was then coated on the sensors and tested with ethanol and methane. The layout design of the width and gap with the greatest sensitivity towards gases is 20 μm/20 μm. The limit of detection (LOD) is 40 ppm for ethanol and 36 ppm for methane; the resistance changes of the two gases are apparently opposite. Besides this, sensors coated with other sensing materials developed with combination of CB,polymers, poly(4-vinylpyridine)(P4VP) and polystyrene (PS) with solvent, EG and Tetrahydofuran (THF) respectively were measured with gases at varied concentration to derive the sensitivity of each. According to these experiments, a flexible gas sensor shows a great potential to achieve the purpose of establishing a wearable sensing platform.

Niobium-added titanium oxides powders as non-noble metal cathodes for polymer electrolyte fuel cells – Electrochemical evaluation and effect of added amount of niobium

An appropriate evaluation of oxide-based compound powders as non-platinum cathodes for polymer electrolyte fuel cells is required to investigate the active sites of oxide-based cathodes for the oxygen reduction reaction. A mixture of carbon black powder as an electro-conductive material with oxide catalysts that had low electrical conductivity was attempted to evaluate the oxygen reduction reaction (ORR) activity. An appropriate mixture of carbon black and the oxide catalysts let to the electrochemical activation of the oxide surface by the formation of electron conduction networks. Using the carbon black mixture, the niobium-added titanium oxides heat-treated at 700 °C for 10 min under Ar containing 4% hydrogen without carbon materials were focused on to reveal the dependence of ORR activity on the added amount of niobium. The ORR activity of the niobium-added titanium oxides increased the Nb mole percentage from 0 to 20. This was due to the increase in the ratio of the Ti3+/(Ti4++Ti3+), and suggests that the active sites were Ti3+ and/or oxygen vacancies in the anatase phase. On the other hand, although the ratio of the Ti3+/(Ti4++Ti3+) of the oxide with an Nb mole percentage of 30 was almost twice as that with an Nb mole percentage of 20, the ORR activities were almost the same. This might be responsible for the deposition of the amorphous phase composed of Nb2O5, which consisted of a thin layer on the surface of the oxide particles and had low ORR activity.

Particle packing in bimodal size carbon black mixtures and its effect on the properties of styrene-butadiene rubber compounds

Particle packing, together with other filler characteristics, can be considered as an important structural parameter of fillers, affecting on the properties of rubber compounds. For this purpose, N220 and N550 carbon blacks with nearly similar structure and surface chemistry but different particle sizes were selected. N220/N550 showed the maximum packed density at the composition 35/65 according to the accepted theory for bimodal packing of spheres. A correlation between the packing behavior of carbon blacks mixtures and physical, electrical and rheological behaviors of filled rubber compounds was investigated. A synergic effect in compounds properties was observed before the vulcanization reaction at the maximum packed composition of carbon-blacks. The synergic effect was attributed to the dense and highly immobilized rubber trapped inside packed structure of carbon blacks aggregates, but it didn't appear for the vulcanizates due to the adverse effect of immobilized rubber on the chemical cross-link density formed during vulcanization reaction. • Particle packing is an important structural parameter in rubber reinforcement. • There is a correlation between particle packing and the properties of filled rubber compounds. • A synergic effect in properties was observed at the maximum packed composition of fillers before vulcanization. • The synergic effect was due to the highly immobilized rubber trapped in the filler network. • The synergic effect was absent in some properties after vulcanization.

Microstructure evolution of Cu-TiC composites with the change of Ti/C ratio

In this work, Cu-TiC composites have been successfully prepared by adding Ti and carbon black powder mixture into Cu melts. The microstructure evolution of the composites with the change of Ti/C ratio and its mechanism has been investigated. It is found that when Ti and carbon black powder mixture is added into Cu melts, Ti will react with carbon black to form TiC, which makes the carbon black be wetted. Then the unreacted Ti will be dissolved and further reacted with the wetted carbon black to form more TiC. However, the formed TiC particles are dispersed difficultly and tend to aggregate into agglomerations. Increasing the Ti/C ratio is an effective method to improve the distribution of TiC. It is found that, comparing with the Cu-4Ti-1C, non-stoichiometric TiCx with smaller x which has the better wettability with Cu melts can be synthesized in the Cu-5Ti-1C and Cu-6.67Ti-1C. As a result, TiC particles are more uniformly distributed in the prepared Cu-Ti-C composites with higher Ti/C ratio.

Numerical Prediction of Multiscale Electronic Conductivity of Lithium-Ion Battery Positive Electrodes

The electronic conductivity, at the multiscale, of lithium-ion positive composite electrodes based on LiNi1/3Mn1/3Co1/3O2 and/or carbon-coated LiFePO4, carbon black and poly(vinylidene fluoride) mixture is modeled. The electrode microstructures are acquired numerically in 3D by X-ray tomography and FIB/SEM nanotomography and numerically segmented to perform electrostatic simulations using Fast Fourier Transform (FFT) method. Such simulations are easy and quick to perform because they are directly computed on the grid represented by the voxels in the 3D volumes. Numerical results are compared with experimental measurements of the multiscale electronic conductivity by broadband dielectric spectroscopy (BDS). A good prediction is realized for the bulk conductivities of the C/LiFePO4 phase and the CB/PVdF mixture. The combination of X-ray and FIB/SEM tomography, FFT simulation method, and BDS is thus well adapted to understand the influence of the electrode composition and microstructure on its electronic conductivity.

Effects of Nitridation Time and Precursor Particle Size on Yield of β-SiAlON Synthesized from Calcined Kaolinite

Carbothermal reduction and simultaneous nitriding (CTRN) of natural aluminosilicates is a method used to obtain phases of Si–Al–O–N system. SiAlON phases have important applications, such as high technology ceramics, for wear parts, cutting tools or special purpose refractory materials. In this study carbothermal reduction and nitriding reactions of kaolinite obtained from Balikesir-Duvertepe area of Turkey were studied. The mean particle sizes of kaolinite used for CTRN process were 6.4, 4.67, and 2.29 μm, respectively. The reactions of kaolinite and carbon black mixture carried out at 1400°C for 2, 4, and 8 h. CTRN process was conducted in an atmosphere controlled tube furnace in nitrogen flow of 4 cm3/min. All products were examined by XRD and SEM to determine the transformation, morphology and chemical composition. The results showed that the most of SiAlON transformations occurred at 1400°C for 8 h. It was observed that when decreasing the mean particle size of the starting material the transformation of kaolinite to SiAlON was increased.

A systematic study of kinetics in mesocarbon microbeads anodes in presence of nano-conductive additives

Nano-conductive additives in composite electrodes play a significant role in influencing the electrochemical performance of the carbon anode in Li-ion batteries. These additives with a high electronic conductivity lead to the formation of a uniform solid-electrolyte interfacial layer, improved cycle life, and rate capability. In this work, the parameters that lead to such a performance improvement, namely the kinetic and transport properties, are carefully studied with carbon black (CB), carbon nanotubes (CNT) and a mixture of the two as conductive additives in mesocarbon microbeads (MCMB) anode. Experimental measurements indicate that the electrochemical reaction rate is controlled by interfacial kinetics up to moderately high C-rate (<6C). Though nano-additives do not affect the solid phase diffusivity, the diffusion of Li-ion is considerably influenced by stages and their coexistence that is revealed through X-ray diffraction of cells at different depths of discharge. Using electrochemical impedance spectroscopy of half-cells cycled at different temperatures, the activation energy for charge transfer reaction and activation energy for SEI layer diffusion are estimated. The results exhibit an improvement in electron transfer and an ionically conducting SEI layer with the use of a mixture of CB and CNT as conductive additives. It is expected that the estimated kinetic and transport parameters and their temperature dependence for the additives under consideration will be of tremendous utility in the thermal, electrochemical, or aging modeling of batteries employing MCMB as anode material.

The Effect of Mechanical Activation on the Physico-Chemical Properties of Carbon Black and Rubber Mixtures Filled with It

The Effect of Mechanical Activation on the Physico-Chemical Properties of Carbon Black and Rubber Mixtures Filled with It

The effect of the ink composition on the performance of carbon-based conductive screen printing inks

Conductive carbon-based screen printable inks are used in a wide range of applications. The aim of the comprehensive study was to monitor how the fundamental components affect the ink performance. In the present work there were prepared several variants of carbon-based inks. The higher ratio of carbon black in the graphite (G):carbon black (CB) mixture, and also the higher total carbon amount have been confirmed to cause an increase in viscosity in the shear rates range from 200 to 1000 s−1. The lowest sheet resistance values were observed with 3:1 G:CB ratio. Increasing of the total carbon amount from 15 to 35 wt% has led to improvement in conductivity with final value of 32.4 Ω sq−1. The increasing ratio of lower boiling point solvents (4-hydroxy-4-methyl-2-pentanone, ethyl alcohol) has led to the improvement of the sheet resistance (lowest value of 22.73 Ω sq−1), while the roughness values increased. In the case of rheological properties evaluation, the ethyl cellulose content modification (increase from 2 to 10 wt% in the binder) resulted in increasing viscosity dependencies. In addition, the increase of the ethyl cellulose content had minimal impact on the roughness, but positive impact on the conductivity. On the other hand, it was identified an unobvious trend after modifying the binder by polyvinylpyrrolidone. To achieve the desired effect on the sheet resistance, volume resistivity and roughness of the printed layers it is necessary to specify the most proper ethyl cellulose:polyvinylpyrrolidone ratio. The main reason is the interaction between the two polymers within the binder.

Experimental and Modeling Study on the Curing Properties of Natural Rubber Composites Filled with Varying Proportions of Carbon Black, Modified Bentonite and Raw Bentonite

The aim of this study was to investigate the effect of replacing carbon black (CB) with inexpensive and environmentally friendly fillers – bentonite (BNT) and modified bentonite (M-BNT), on the curing properties of natural rubber (NR) composites. A control sample (unfilled NR) and thirteen NR composites filled with varied proportions of CB (x1), M-BNT (x2), and BNT (x3) based on a third degree – simplex lattice mixture design of experiment (DOE) were prepared in this study. Rheometric results showed that 33% substitution of CB with M-BNT provides the highest elastic torque values. Mixture of 10phr CB and 5phr M-BNT (CB/M-BNT/BNT 10/5/0) produces synergistic effect on curing. The presence of CB increases vulcanization rate due to its high basicity and low oxygen content while M-BNT serves as vulcanizing accelerator due to the present amine groups. Coefficients of reduced hierarchical models showed that the main factors contributed mainly on the curing parameters: β1 for the torque values, β2 for the scorch and curing time, and β3 for CRI. High values of coefficient of determination (r2) were computed particularly for MH (98.20%), ΔS (99.13%), ts2(95.68%), tc90(95.70%) and CRI (95.97%) establishing best fit between the model and experimental values.

Polyamide 6 composite fibers with incorporated mixtures of melamine cyanurate, carbon nanotubes, and carbon black

AbstractPolyamide 6 (PA6) composite filament yarns were produced by the simultaneous incorporation of melamine cyanurate (MeCy) with multiwalled carbon nanotubes (CNTs) and carbon black (CB) into a composite matrix in a melt‐spinning process. The results show that the simultaneous incorporation of MeCy with CNTs or CB additives provided filaments with a uniform black color. Tensile analysis confirmed that a reinforcing effect was achieved when CB was used, whereas the CNTs induced a reducing effect on the filament tenacity. With regard to the burning behavior, the flame‐retardant action of MeCy was preserved in the presence of CB but was significantly hindered when used in combination with CNTs. These results indicate that the mixture of MeCy and CB was much more compatible for the production of reinforced PA6 composite filaments with increased thermal stability and improved flame retardancy over those of the MeCy and CNTs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47007.

Performance Prediction and Scaling Laws of Circular Dielectric Elastomer Membrane Actuators

For a number of emerging mechatronics applications, dielectric elastomers (DEs) appear as a more energy efficient, lightweight, and low-cost solution with respect to established actuation technologies based, e.g., on solenoids or pneumatic cylinders. In addition to large strain, low power consumption, and high flexibility, DE actuators (DEA) are also highly scalable. Since DE membranes can be easily manufactured in different sizes and shapes, an effective approach to scale their performance is based on properly designing the material geometry. Clearly, to perform an optimal scaling the relation between material geometry and performance has to be properly investigated. In this paper, performance scaling by means of geometry is studied for circular out-of-plane (COP) DEAs. Such actuators consist of a silicone elastomer membrane sandwiched between two electrodes (carbon black silicone mixture). DEAs with six different geometries are manufactured, and a model-based strategy is used to find an experimental relationship between geometry and electro-mechanical behavior. In addition, an effective and computationally efficient method for predicting force–displacement characteristics of different geometries is presented. The proposed method allows to easily adapt DEAs to different applications in terms of stroke and force requirement, while minimizing at the same time both characterization and prototyping effort.