Carbon Black Ratio Research Articles

Modeling of Carbon Mortar Color Expression Using Artificial Neural Network.

Colored concrete uses pigments and white Portland cement (WPC) to perform decorative functions together with structural function. Pigments are used in permanent coloring of concrete with colors different from the natural color of the cement or the aggregates with mixing WPC. In this study, an artificial neural networks study was carried out to predict the color evaluation of black mortar using pigment and carbon black. A data set of a laboratory work, in which a total of 9 mortars were produced, was utilized in the Artificial Neural Networks (ANNs) study. The mortar mixture parameters were nine different pigment and carbon black ratios. Each mortar was measured at ten locations on the surface and averaged. Color can be evaluated by measurements of tristimulus values L* , a* and b* , represented in the chromatic space CIELAB. The L* value is a measure of luminosity (0 darkness), from completely opaque (0) to completely transparent (100); a* is a measure of redness (-a* greenness) and b* of yellowness (-b* blueness). ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of three input parameters that cover the pigment, carbon black and WPC and, an output parameter which is the color parameters of the black colored mortar. The results showed that ANN can be an alternative approach for the predicting the color parameters using mortar ingredients as input parameters.

Facile synthesis of cobalt oxide as electrocatalyst for the oxygen reduction reaction in microbial fuel cells

Cost-effective cobalt oxides were synthesized at mild condition as alternatives to platinum catalyst for oxygen reduction in microbial fuel cells (MFCs). The catalysts were prepared by heating Co(NO3)2 above its decomposition temperature together with carbon black (CB). At a catalyst loading of 5 mg/cm2, cobalt oxide cathodes with a Co(NO3)2 to CB ratio of 0.732:1 produced a maximum power density of 1220 mW/m2, which was slightly lower than that of Pt/C cathodes (1360 mW/m2). Further increase in the loading of cobalt oxides resulted in an increase in performance. The maximum power densities produced by cobalt oxide cathodes increased to 1400 mW/m2 at a catalyst loading of 20 mg/cm2 and 1540 mW/m2 at 30 mg/cm2, which outperformed the Pt/C control. The durability of cobalt oxide catalysts was comparable to that of Pt/C in single-chamber MFCs with biological contamination. The costs of cobalt oxide catalysts were much lower than that of Pt/C catalyst, even when the loading of cobalt oxides was several times higher than Pt/C catalyst. These findings show that the facilely synthesized cobalt oxides were cost-effective catalysts for oxygen reduction in air-cathode MFCs.

Resistance Reduction Effect by SDX® in Lithium-Ion Batteries

1. Introduction Practical uses of lithium-ion batteries(LIB) are rapidly growing especially in large batteries for full electric vehicle(EV), plug-in hybrid electric vehicle(PHEV) and so on, but improvements of their characteristics(“high-energy density”, “high power”, “long cycle-life”, “safety” and “lower cost”) are still strongly demanded. SDX® is a surface coated aluminum current collector(AL) with carbon black(CB) and organic binder, and the thickness of the coated layer is about 1μm, and SDX®makes a cell internal resistance lower and adhesion between cathode active materials and AL stronger, so as to improve battery performance dramatically[1,2]. The control of the internal resistance of LIB by the clarification of the mechanism is one of the biggest key items to improve them. So the mechanisms of the interface resistance between cathode active material layer and AL have been investigated and discussed[3]. In general, cell internal resistance is separated simply into electronic resistance and ionic resistance. We successfully separated the electronic resistance into material resistance and interface resistance between cathode active material layer and AL. And then we independently measured the material resistance and the interface resistance by Electrode Resistance Meter(HIOKI E.E. CORPORATION) which can separate electrode resistance into material and interface resistance. In the battery which used LFP as cathode active material, the quantitative investigation of the contribution of SDX® and conducting additives to the electronic resistance reduction was provided by the result of measurement using Electrode Resistance Meter(Fig.1). The interface resistance of the cathode with AL was higher than the material resistance of that by almost one order of magnitude. The interface resistance of the cathode with SDX® was lower than that with AL by almost one order of magnitude. It is not only presumed that the interface resistance is dominant in the electronic resistance but confirmed that the interface resistance is maintained at lower level by SDX®. Because the interface resistance was reduced by SDX®, it has been reported that conducting additives could be reduced much in cathode[4]. By application of SDX®, it was confirmed that the interface resistance of LFP could be decreased largely irrespective of a distribution state of conducting additives. As a result, cell internal resistance and discharge capacity retention of LFP was constant irrespective of coating speed[5]. In this paper, more detailed examination will be carried out, and resistance reduction effect by SDX®in LIB will be tried to be clarified. 2. Experiment Firstly, the preparation of electrode slurry was carried out by dispersing LFP as a cathode active material, CB as a conducting additive and polyvinylidene difluoride(PVdF) as binder into N-methylpyrrolidone(NMP). The compounding ratio of LFP, CB and PVdF was set to 90:5:5 as a solid mass ratio. Secondly, cathode electrodes were prepared by coating the slurry onto AL or SDX®and dried, before they were pressed at several conditions(e.g. 1.6, 2.0 or 2.5g/cc). By laminating one sheet of anode and one sheet of cathode, pouch type cell was assembled. 3. Results and discussion The material resistance and the interface resistance of the cathode were measured by Electrode Resistance Meter(Fig.2). The interface resistance of the cathode with AL increased as the electrode density lowered and finally the interface resistance of the cathode of electrode density of 1.6g/cc with AL could not be measured because of high resistance. On the other hand, it was confirmed that the interface resistance of the cathode with SDX®was constant irrespective of the electrode density. Cell internal resistance(DCR) were measured(Fig.3). The cell DCR with AL increased when the electrode density lowered, and the cell of the cathode of electrode density of 1.6g/cc with AL did not work because of high resistance. It was confirmed that the cell DCR with SDX® was constant irrespective of the electrode density showing similar behavior to the interface resistance of the cathode with SDX®. Cell discharge performance was also evaluated(Fig.4). It confirmed that the cell discharge performance of the cathode of electrode density of 2.5g/cc with AL was almost same as that with SDX®. But when the electrode density with SDX® lowered, especially at high rate(10, 20C), the cell capacity retention with SDX®was improved.

Full Factorial Experiment to Determine and Predict Impact of Cerium Amount on Fuel Cell Performance

Understanding the relationship between mobile additives in the membrane and critical electrode factors is important for enabling cost-effective and long-lasting fuel cell systems. This work investigates performance impacts due to the interaction between cathode variables and cerium loading in the membrane. A statistical model is applied to separate the importance of each factor with respect to the performance signal. It was found that the ionomer to carbon black ratio has the largest effect on current density. The electrode ionomer type is a secondary effect only under very dry conditions. The conclusion is that optimizing ionic conductivity in the cathode is the most important factor for maintaining performance when cerium ions are present.

Dope dyeing of lyocell fiber with NMMO-based carbon black dispersion

NMMO-based carbon black (CB) dispersion was prepared and its properties as well as its compatibility with lyocell spinning solution were further investigated. Modified lignosulfonate (SP) was verified to be the preeminent dispersant for the preparation of NMMO-based CB dispersion with mass ratio of SP to CB 20% and water to NMMO 13%. The compatibility of NMMO-based CB dispersion with lyocell spinning solution had close relation with dispersant structure and CB content. Mass ratio of CB to cellulose affects the mechanical properties, color strength and crystallinity of lyocell fiber. 0.5% CB increased the breaking strength and elongation of lyocell fiber, whiles breaking strength and elongation of the lyocell fiber were reduced slightly when 2.0% CB was used. The dope dyed fiber showed excellent rubbing and washing fastness as well as migration resistance to water, ethanol and acetone.

The effect of graphite and carbon black ratios on conductive ink performance

Conductive inks based on graphite and carbon black are used in a host of applications including energy storage, energy harvesting, electrochemical sensors and printed heaters. This requires accurate control of electrical properties tailored to the application; ink formulation is a fundamental element of this. Data on how formulation relates to properties have tended to apply to only single types of conductor at any time, with data on mixed types of carbon only empirical thus far. Therefore, screen printable carbon inks with differing graphite, carbon black and vinyl polymer content were formulated and printed to establish the effect on rheology, deposition and conductivity. The study found that at a higher total carbon loading ink of 29.4% by mass, optimal conductivity (0.029 Ω cm) was achieved at a graphite to carbon black ratio of 2.6 to 1. For a lower total carbon loading (21.7 mass %), this ratio was reduced to 1.8 to 1. Formulation affected viscosity and hence ink transfer and also surface roughness due to retention of features from the screen printing mesh and the inherent roughness of the carbon components, as well as the ability of features to be reproduced consistently.

PROPERTIES OF SBR FILLED WITH CARBON BLACK AND ARAMID PULP HYBRID FILLER: COMPARISON BETWEEN PREDISPERSED ARAMID PULP AND CONVENTIONAL ARAMID PULP

ABSTRACT Compounds of SBR incorporated with hybrid filler of carbon black (CB) and aramid pulp were prepared. The ratio of CB to aramid pulp was varied and its effects on viscoelastic and mechanical properties of the rubber were investigated. Two aramid pulp types were used in this study: conventional aramid pulp (CAP) and the predispersed aramid pulp (PAP). The rubber–filler interaction as indicated by bound rubber content decreases with increasing aramid pulp loading, regardless of the aramid pulp type. This results in a decrease in tensile and abrasion properties with increasing fiber loading. The energy dissipation properties of the hybrid composites are also poorer than those of the CB/SBR composite, as reflected by the heat buildup values. Use of predispersed aramid fiber resulted in improved dispersion of the fiber in SBR. Thus, Mooney viscosities of the PAP-filled systems are lower than those of the CAP-filled systems, but the percentages of elongation at breaks are higher. The distinct feature of aramid fiber/CB hybrid SBR composites is their high moduli over an extended range of temperatures up to 80°C that is unattainable with the use of CB alone.

Synergistic effect of carbon black and carbon-silica dual phase filler in natural rubber matrix

In this article, the synergistic effects of carbon black (CB) and modified carbon–silica dual phase filler (MCSDPF) on the properties of natural rubber (NR) were investigated. MCSDPF was prepared by modifying carbon–silica dual phase filler (CSDPF) with bis(3-triethoxysilylpropyl)tetrasulphane (Si-69). Fourier transform infrared spectroscopy and thermogravimetric analyzer analyses revealed that Si-69 was successfully grafted to CSDPF. NR-based compounds containing various combinations of MCSDPF and CB were prepared through a mechanical mixing. Investigations of mechanical properties, ageing resistance, abrasion resistance, dynamic mechanical properties, and morphology of tear fractured surface of MCSDPF/CB/NR vulcanizates were conducted. Our study shows that adding MCSDPF led to significant improvement in the tear resistance, fatigue life, and elongation at break of MCSDPF/CB/NR vulcanizates. Optimum stoichiometric combination of MCSDPF and CB inside the NR matrix was derived (ratio of MCSDPF and CB in wt% = 15/50), which showed synergistic effects of MCSDPF upon CB that was ultimately reflected in their tensile strength, wet skid resistance, and rolling resistance. POLYM. COMPOS., 35:1466–1472, 2014. © 2013 Society of Plastics Engineers

Microstructure and rheological properties of titanium carbide-coated carbon black particles synthesised from molten salt

Homogeneous titanium carbide (TiC) coatings were prepared on carbon black (CB) particles by firing them with metallic titanium (Ti) powder in KCl or KCl–LiCl for 4 h at 750–850 °C. As-prepared TiC-coated CB retained the spherical shape of as-received CB, indicating that the ‘template-growth’ mechanism had dominated the reaction process. TiC coating thickness could be readily tailored by simply adjusting the Ti to CB ratio (Ti/C) of the initial starting mixture. The true density of TiC-coated CB particles increased with Ti/C, reducing the density difference between them and other aggregates used in castable systems and potentially improving the castables consistency. Zeta potential measurement, sedimentation comparison and rheology testing revealed that water-wettability and dispersivity of CB were improved significantly after TiC coating.

Effect of substrate and catalyst on the transformation of carbon black into nanotubes

Structural transformation of carbon black (CB) into nanotubes and nano-onion like structures in the presence of bimetallic catalysts (Fe and Ni) is reported and the influence of the substrate (alumina and stainless steel) in the structural transformation is studied. In addition, the importance of a specific weight ratio of CB to catalyst in the transformation of amorphous CB into graphitic nanostructures is verified. The experiments were carried out at 1,000 °C in a horizontal tube furnace under N2 atmosphere. The samples were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy and also thermomagnetic analysis (Curie-temperature determinations) were done to assess thermally induced magnetic phase changes. All the characterization techniques showed the resulting structures were influenced by the substrate and weight ratio for CB to catalysts. However, there was no significant difference in the magnetic performance of the resulting structures obtained on different substrates.

Molten salt synthesis and characterization of SiC coated carbon black particles for refractory castable applications

Silicon carbide (SiC) coatings were prepared on carbon black (CB) particles after 6 h at 1100 °C by a molten salt synthesis (MSS) technique. By controlling the Si to CB ratio (Si/C) in the initial batch mixture, the SiC coating thickness could be readily tailored to meet practical requirements in real castable systems. True densities of CB particles after SiC coating increased with Si/C. The zeta potential values indicated that their dispersivity was improved evidently over a wide range of pH. At a given shear rate, the apparent viscosity of a water suspension containing SiC-coated CB was significantly lower than that of a water suspension containing as-received uncoated CB, indicating the improved flowability of SiC-coated CB in water. The improvements in both the water-dispersivity and flowability of SiC coated CB particles would make them a promising candidate carbon material for future castable applications.

Carbon black modification of mesophase pitch-based carbon fibers

The effects of carbon black (CB) on the microstructural development within mesophase pitch-based carbon fibers are reported. Unlike carbon nanotubes, which were previously studied for modifying fiber microstructure, CB represents a significantly lower cost alternative making it more favorable for industrial application. Additionally, the aspect ratio of CB is much closer to unity than carbon nanotubes, which have an aspect ratio ∼100 to 1000. Fibers were produced by first dispersing CB into a synthetic mesophase pitch at a dilute concentration of 0.3wt%. These precursor materials were spun and then processed into carbon fibers. Unmodified (0wt%) carbon fibers exhibited a severe radial texture with increasing orientation of graphitic pleats away from the fiber core. Carbon fibers modified with CB showed a strong flat layer structure, with only a slight increase in pleat folding away from the core. This difference in structure was also accompanied by a decrease in the number of fibers that exhibited “pac-man” splitting. No discernable reduction was observed in the graphitic crystallinity (interplanar spacing and crystallite size) or axial orientation of crystallites within the fiber, as a result of nanomodification.

Preparation of nanoscale carbon black dispersion using hyper-branched poly(styrene-alt-maleic anhydride)

Hyper-branched poly(styrene-alt-maleic anhydride) (BPSMA) was used as a dispersant to disperse carbon black (CB) in aqueous media. The dispersing ability of BPSMA for CB was estimated by measuring the particle size, zeta potential, stability to temperature and centrifugal stability of BPSMA-dispersed CB dispersions. The experimental results showed that BPSMA prepared with a molar ratio of 4-vinylphenyl methanethiol (VPMT), St and MA at 6:47:47 and a mass ratio of BPO and (VPMT+St+MA) at 1:50 exhibited optimal dispersing ability when the CB dispersion was at pH 8, and a mass ratio of BPSMA and CB was about 1:5. Compared to linear poly(styrene-alt-maleic anhydride) (LPSMA), BPSMA prepared CB pigment dispersion with a smaller particle size, a more narrow particle size distribution and higher stabilities.

Study on Reinforcement of SBR by the Blending System of Nanosilica and Carbon Black

Reinforcement of SBR composites by nanosilica blending with carbon black (CB) can bring obviously synergistic effects. Compared with single use of nanosilica, the mechanical performances of the vulcanized SBR (styrene butadiene rubber) were greatly improved and the best mechanical performance is at the blending ratio of CB N330/silica at 50/5. Compared with single use of carbon black, the anti-fatigue and anti-aging performances of the vulcanized blending system were improved remarkably, and the anti-fatigue performance showed an increasing tendency with the increase of nanosilica, and the anti-aging performance will reach to the maximum value when the blending ratio of CB N330/silica is at 40/15. The modification mechanism of blending system is given.

Surfactant‐dispersed carbon black in polyimide nanocomposites: Spectroscopic monitoring of the dispersion state in the polymer matrix

AbstractThe effects of an anionic surfactant on the dispersion of carbon black (CB) for the purpose of forming conducting composite films were examined with ultraviolet–visible (UV–vis) absorption spectroscopy. To obtain a good dispersion and size reduction of aggregated CB in a polymer matrix, sodium dodecyl sulfate (SDS), used as a surfactant, was introduced into a CB suspension. A set of concentrations with various ratios of CB to SDS (ranging from 1 : 0.4 to 1 : 10) was established before mixing with poly(amic acid) (PAA), a precursor of pyromellitic dianhydride and oxydianiline, was performed. The CB/PAA solution mixtures were submerged under an ultrasonic bath for several hours, then cast onto dry plate glasses, and finally subjected to thermal imidization to produce CB/polyimide (PI) nanocomposite films with various CB weight fractions ranging from 0.025 to 0.50 wt %. A method for evaluating the absorbance at 500 nm of the CB/PI nanocomposite films was established. The absorbance of CB/PI nanocomposite samples of various thicknesses was also normalized to get rid of the effects of the different thicknesses. UV–vis spectra showed that the minimum weight ratio of CB to SDS in the nanocomposite films that achieved well‐dispersed CB and still had transparent properties was 1 : 2.0. Transmission electron microscopy demonstrated that CB was dispersed homogeneously in the PI matrix, and the size of the aggregated CB was affected by the amount of the surfactant. The dielectric properties of the nanocomposite films without the surfactant increased by approximately 2 orders of magnitude with an increasing mass weight fraction of CB and decreased when the surfactant was added. The surfactant also reduced the tensile strength of the CB/PI nanocomposites when the CB/SDS ratio was higher than 1 : 2.0. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

The influence of synergistic stabilization of carbon black and clay on the electrical and mechanical properties of epoxy composites

Studies of acetone-based suspensions suggest a synergistic stabilization of clay by carbon black (CB) that involves a haloing effect (i.e., CB surrounding clay). This unique microstructural development ultimately influences the electrical and mechanical properties of epoxy composites that contain both particles. With the addition of 0.5 wt.% clay, electrical conductivity increases by an order of magnitude for CB filled epoxy (relative to composites containing no clay), but no significant improvement is observed in storage modulus. Composites containing equal concentrations of CB and clay show reduced electrical conductivity, but significant improvement in storage modulus (relative to the composites containing equal amount (wt.%) of either CB or clay alone). Both electrical conductivity and storage modulus improve in composites containing a 1:2 clay:CB (wt/wt) ratio. This synergy between CB and clay is a useful tool for simultaneously improving the electrical and mechanical properties of solution-processed composites.

ＮＲ／ＳＢＲブレンド系ゴム組成物の力学的特性とカーボンブラックの分配挙動

Grip performance and braking distance of a tire strongly depend on the frictional characteristics between the tread (the part which touches to the road surface) rubber and the road surface. To meet the complex needs of a tire, a polymer blend is commonly used and the fillers in the polymer blend may have a great influence on tire properties. In this paper, a bias dispersion state of carbon black (CB) in polymer blended rubber composites consisting of styrene butadiene rubber (SBR) and natural rubber (NR) was observed by scanning probe microscope (SPM). It was indicated that the SBR/CB interaction in rubber composite was stronger than that of the NR/CB interaction by measuring tensile strength in NR/SBR blended rubber composites. It was found that island patterns of SBR phase were formed in the polymer and more carbon blacks were segregated in SBR phase than in NR phase. Then a method to predict the distribution ratio of CB in SBR phase was proposed according to characteristic behavior of storage modulus in dynamic viscoelasticity. And the concentration of CB in SBR phase was estimated to be about twice as large as that in NR phase.

Characterization of Carbon Filler Distribution Ratio in Polyisoprene/Polybutadiene Rubber Blends by High-Resolution Solid-State 13C NMR

The distribution ratio of carbon black (CB) in a blend of polyisoprene rubber (IR) and polybutadiene rubber (BR) is characterized using high-resolution solid-state 13C NMR. The relationships between the line width of the polymer's resonance lines and CB contents are estimated for both the IR/CB and BR/CB composites from the dipolar decoupling/magic angle spinning (DD/MAS) 13C NMR spectra. For the IR/CB composite, the IR line width increases with the increasing CB content. A similar relationship is obtained between the BR line width and CB contents for the BR/CB composite. These relationships are used as calibration curves. On the basis of these calibration curves, the distribution ratio of CB in the IR/BR rubber blend is determined. It is found for the IR/BR/CB composite that the amount of CB in the BR phase is approximately twice as high as that of CB in the IR phase, irrespective of the CB content. The sum of the amounts of CB in both the IR and BR phases, determined from the above 13C NMR experiments, mostly agree with the amount of CB originally added to the compound. This verifies the validity of the CB distribution determination method by 13C NMR, as proposed in this study. A comparison with a CB-gel method, which can only be used for unvulcanized rubber blends, further confirms the results obtained from the 13C NMR.

Viscoelastic properties of natural rubber composites reinforced by defatted soy flour and carbon black co-filler

Filler mixtures of defatted soy flour (DSF) and carbon black (CB) were used to reinforce natural rubber (NR) composites and their viscoelastic properties were investigated. DSF is an abundant and renewable commodity and has a lower material cost than CB. Aqueous dispersions of DSF and CB were first mixed and then blended with NR latex to form rubber composites using freeze-drying and compression molding methods. A 40% co-filler reinforced composite with a 1 : 1 DSF : CB ratio exhibited a 90-fold increase in the rubber plateau modulus compared with unfilled NR, showing a significant reinforcement effect by the co-filler. The effect, however, is lower than that observed in the carboxylated styrene–butadiene rubber composites reported earlier, indicating a significant effect from the rubber matrix. The co-filler composites have elastic moduli between those of DSF and CB reinforced composites. Stress softening and recovery experiments indicated that the co-filler composites with a higher CB content tend to have a better recovery behavior; however, this can not be simply explained from the recovery behaviors of the single filler (DFS and CB) composites. CB composites prepared by freeze-drying show a strain-induced reorganization of fillers. Strain sweep experiment data fit with the Kraus model indicates the co-filler composites with a higher CB content are more elastic, which is consistent with the recovery experiments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Properties of a carbon filled cyclic olefin copolymer

AbstractThis article investigates electrical conductivity and rheological aspects of cyclic olefin copolymer (COC) composites containing both carbon fiber (CF) and carbon black (CB) at various concentrations. The different formulations of carbon filled COC were compression molded in such a manner that the formed circular sheets exhibited preferred in‐plane filler orientation. Through‐plane and in‐plane conductivity were measured by 2‐probe and 4‐probe methods, respectively, while an ARES rheometer in dynamic mode was employed to measure the storage modulus and complex viscosity. It was found that formulations with CF:CB ratios around 3 and where the CB content was close or below its critical percolation concentration resulted in higher electrical conductivity while maintaining the viscosity of the composite at a level acceptable for polymer processing machinery. For those composites containing both fillers, collaborative associations between the CB and CF fillers were found in the established percolating network structure, producing measured conductivities which exceeded the estimated values by the additive rule by up to sixfold. An empirical expression to handle hybrid filler systems is proposed in this work based on the standard percolation model. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1808–1820, 2007