Carbon Black Particle Size Research Articles

ELECTRICAL CONDUCTIVITY OF RUBBER COMPOUNDS: REVISITING THE INFLUENCE OF FUNDAMENTAL CARBON BLACK PROPERTIES

ABSTRACT Carbon blacks are electrically conductive; however, when carbon black is used as particulate reinforcement in a rubber compound, the compound electrical conductivity can vary from insulative to fully conductive depending on the loading level and properties of the carbon black. An investigation of the influence of three fundamental properties of carbon black—particle size, structure, and porosity—on rubber compound electrical conductivity was conducted. The deconvolution of these three parameters within the study allows for conclusive results to be drawn on what drives compound electrical conductivity and the underlying principles. The work is split into two parts: (1) a determination of the influence of particle size and structure and (2) the influence of porosity. Particle size traces its influence back to numerous particles are in a given volume of rubber compound. Structure’s influence on electrical conductivity varies with the particle size of the carbon black and is for the first time traced back to the aspect ratio of the aggregates. Porosity is separated as a variable in this work by introducing discrete levels of porosity to nascent carbon blacks via gasification. The results show that the impact of carbon black porosity on electrical conductivity in rubber compounds arises from a change in its envelope density and is not due to any change in the inherent aggregate conductivity.

Influence of carbon black particle size on fatigue life of rubber compound by varying strain and temperature

AbstractFatigue failure is one of the most critical failure modes in engineering structures. The fracture process proceeds through two major phases: crack nucleation and subsequent crack propagation leading to the ultimate failure. With special reference to rubber products especially tyre, the fatigue crack growth characteristics have been well understood with good approximation by many researchers. But the experimental research on crack nucleation is in the nascent stage. In the present study, we have focused on the role of filler particle size, temperature and strain on crack nucleation and fracture surface morphology of unfilled and carbon black (CB)‐filled natural rubber (NR) compounds. Three different kinds of ASTM grade carbon blacks, namely, N134, N234 and N339 have been used to determine the effect of filler particle size on crack initiation. All compounds have been tested at room temperature (i.e., RT 25°C), 70°C and 100°C with different strain amplitudes (50%, 75%, 100%, and 125%) to understand its effect on damage mechanics. It is observed that at a given strain and temperature, compound with N134 has better fatigue life in comparison to the N234 and N339. It is also found that with increasing temperature, fatigue life is being reduced for all the compounds. Optical microscope and field emission scanning electron microscope (FESEM) along with micro computational tomography (CT) have been utilized to understand the failure mechanism which reveal the presence of initial flaws as filler protrusions that creates micro cracks during fatigue loading and thus leads to crack nucleation.

Effect of carbon black particle size in chitin sponges on microplastics adsorption

Microplastics (MPs) pollution is becoming a serious challenge, but the adsorption efficiency of adsorbents cannot meet the high requirements of environmental protection, and the adsorption mechanism of MPs is not clear at present. To improve the MPs adsorption efficiency of chitin sponges, this work introduced carbon black (CB) with different particle sizes into chitin matrix to prepare Chitin-CB sponge (ChCB) and explored the relationship between embedded adsorbent particle size and its adsorption effects on MPs. With the decrease of CB particle size from 180 to 40 μm, the removal efficiency of MPs increased from 83.9% to 90.2%. The primary driving force of MPs adsorption was proved to be π-π interaction. Smaller CB provided higher surface energy, enhanced the π-π interactions to MPs and thus showed higher removal efficiency. The results of adsorption kinetics indicated that the MPs adsorption on ChCB fitted with the pseudo-second-order model, indicating that the adsorption process is chemisorption. The results of isotherm at different temperatures and the thermodynamic parameter calculation showed that MPs adsorption conformed to the Freundlich isotherm model, and the adsorption process of MPs is multi-layer spontaneous adsorption. The adsorption intensity value was in the range of 0 ∼ 1, suggesting that ChCB was strong adsorbent material. Moreover, the high porous ChCB shows high water adsorption and excellent physical properties, which facilitated to its application on MPs adsorption. These findings provided valuable experience for the study of the adsorption mechanism of MPs and could guide the design of MPs adsorption materials.

Ex Situ Study on the Co-Preparation of Pitch and Carbon Black from Petroleum Residue to Improve the Cost-Efficiency of the Pitch Synthesis Plant.

This study aims to improve the economic efficiency of the pitch synthesis reaction on the pilot plant by optimizing the pitch synthesis reaction and utilization of the byproduct. The pitch was synthesized using a 150 L pilot plant with pyrolyzed fuel oil as a precursor. The pitch synthesis reaction is carried out through volatilization and polycondensation, which occur at 300 and 400 °C. Volatilization is terminated during heating; thus, additional soaking time is meaningless and reduces the process efficiency. Soaking time is a major variable when the synthesis temperature exceeds 400 °C. The byproduct is generated through volatilization; thus, its chemical characteristics are only influenced by the reaction temperature. The byproduct consists of various polycyclic aromatic hydrocarbons. The average molecular weight and yield of the byproduct increase with the reaction temperature. Carbon black was synthesized using chemical vapor deposition from the byproduct. The particle size of carbon black was controlled by the used precursor (byproduct), and the electrical conductivity of prepared carbon black has a maximum of 58.0 S/cm. Therefore, carbon black, which is synthesized from the byproduct of pitch synthesis, is expected to be used as a precursor for conductive material used in lithium-ion batteries or supercapacitors.

Significant Influence of Bound Rubber Thickness on the Rubber Reinforcement Effect.

In this work, the contribution of different types of carbon blacks (N115, N330, N550, N660) and their primary and secondary thermally cracked recovered carbon blacks to the mechanical properties of NR composites was evaluated. The thermally cracked recovered carbon blacks were prepared by cracking the rubber composites at 500 °C and de-hybridizing them at 900 °C. The characterization of the thermally cracked recovered carbon blacks by scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy showed that carbon blacks after primary and secondary thermal cracking recovery were more prone to aggregation and exhibited a higher degree of carbon defects. The number and type of functional groups on the surface of these carbon blacks were significantly reduced. For NR composites with pristine samples added, the mechanical properties and the bound rubber content tests showed that the mechanical properties of the NR composites became weaker with the increase in carbon black particle size. The bound rubber content also decreased with increased carbon black particle size. The mechanical properties of the NR composites reinforced with carbon black recovered by primary and secondary thermal cracking would therefore decrease. The results of AFM and DSC tests further confirmed the decreasing trend of bound rubber. The present work demonstrates the effect of bound rubber content variation on the mechanical properties of rubber, demonstrates the morphology of bound rubber more visually, and provides new insights into the reinforcement theory of CB.

The Carbon Black Dispersion Index DICB: A Novel Approach Describing the Dispersion Progress of Carbon Black Containing Battery Slurries

The targeted adjustment of carbon black (CB) particle size in electrode slurries is a key step in battery production. Based on the energy input and dispersion device, the resulting particle structure of CB differs significantly. Most frequently, especially in more recent publications, the median particle size was used to describe changes during dispersion. However, this value does not contain enough information to describe the dispersion progress of bimodally distributed particles sufficiently. In this short communication, a novel approach describing the dispersion progress of CB containing slurries is introduced. This method was developed utilizing the hierarchical structure and fragmentation behavior of CB. The Carbon Black Dispersion Index DICB allows quick and easy assessment of the dispersion progress by isolating the CB aggregates of the bimodal distribution. This value offers major benefits with regards to quality control and production monitoring.

Modeling Approaches for the Description of the Carbon Black Particle Size in Batch and Continuous Dispersion Processes for Lithium-Ion Battery Slurries

Energy storage is a key technology for alternative power trains like electric and hybrid electric vehicles. Lithium-ion batteries (LIB) are widely used for this purpose due to their high energy density and elaborated developmental state. Also, the increasing usage of electrified transportation leads to ever-increasing demands on LIBs in terms of fast charging ability and power density. The fragmentation of carbon black (CB) aggregates and agglomerates, respectively, has high impact on the resulting microstructure and mechanical integrity as well as conductivity of electrodes and furthermore, the electrochemical performance of LIBs [1]. To achieve optimized cell performances and to reduce the process times or increase throughputs while conserving the slurry quality, a method to predict the CB particle sizes based on simulations and experiments has been developed.This work demonstrates how the dispersion process can be modelled, thus laying the foundation for an optimized microstructure of the electrode right at the beginning of the process chain. For this purpose, a high-intensity batch process in a planetary mixer is investigated and modelled for the description of the CB fragmentation, and the approach is then applied to a continuous twin-screw extruder. Through the use of computational fluid dynamics, theoretical equations and considerations, and experimentally obtained data, the models are parametrized and can be used to predict the result of the dispersion process in form of the CB particle size. The critical values here are the shear rate in the laminar flow and the viscosity of the slurry, which determine the transferred energy onto the particles during the process. By appropriately modelling these characteristic values, it is possible to transfer the models to machines of different types and designs.Furthermore, it is shown how the predicted particle size of CB affects the microstructure of the electrodes. For this purpose, an innovative structural parameter is calculated from mercury intrusion measurements of manufactured electrodes, which expresses the internal porosity of the CB particles, or of the conductive microstructure, respectively. Based on the modelled CB particle size, this parameter can already be used to estimate the developing microstructure of the electrodes depending on the selected process parameters during dispersion. Such an approach is the basis for further work in order to holistically depict and digitalize the entire process chain of the LIB production and its counteracting influences.The experimental process data (power uptake of dispersion machines, viscosities, CB particle sizes), electrode structures, electrode properties (adhesive tensile strengths, spec. resistances) and cell performance data are shown to illustrate the approaches and the value of the created models. All LIB cathodes investigated consist of industrially relevant formulations (> 95 wt% active material NMC622, < 2.5 wt% CB). Reference s : [1] Mayer, J. , Almar, L., Asylbekov, E., Haselrieder, W., Kwade, A., Weber, A. and Nirschl, H., Influence of the Carbon Black Dispersing Process on the Microstructure and Performance of Li‐ion Battery Cathodes, Energy Technol. (2019)

Influence of process variables on shoe polish viscosity

Valourisation of non-biodegradable wastes into value added products like shoe polish can indeed be an effective tool for waste management and climate change mitigation. However, having appropriate shoe polish viscosity is important for customer satisfaction as too thick or too thin shoe polish may not result in desired customer satisfaction. The aim of this study was to investigate the effects of process variables (water repellant nature, process temperature, carbon black source and particle size, as well as, composition type and quantity) on shoe polish viscosity. The viscosity values of the various samples of shoe polish produced using carbon black pigments from batteries, pyrolytic rubber tyres, plastic bottle and water sachets wastes were determined. From the results obtained, it could be observed that shoe polish samples that had almost the same value of dynamic viscosity (η = 0.2389) with that of the commercial Kiwi shoe polish included the shoe polish with used vegetable oil as water repellant and the shoe polish with dye sourced from discarded batteries and plastic bottle wastes but with particle sixe of 0.80 mm. On comparison of the viscosity values of other shoe polish samples with that of the Kiwi shoe polish, it was observed that all shoe polish samples evaluated for all the distinctive process variables except temperature had comparable viscosity with that of Kiwi shoe polish. The real difference in viscosities of the shoe polish samples was observed when the process temperature was below 60 °C. This indicates that temperature as a process variable is the main determining factor regarding the viscosity of the shoe polish samples.

Fatigue crack growth behavior and morphological analysis of natural rubber compounds with varying particle size and structure of carbon black

AbstractCarbon black (CB) is an essential ingredient of any rubber compound to achieve the desired strength, stiffness, wear, and fatigue resistance. Depending on the function of a tire component (tread, sidewall, apex, etc.), different types of CBs, varying in particle sizes and structures, are used. On prolonged exposure to cyclic loading, rubber compounds lose their strength due to mechanical fatigue. In this study, the fatigue crack growth (FCG) behavior of unfilled and CB‐filled natural rubber compounds is investigated with varying particle size and structure (N115, N134, N220, N234, N330, and N339). FCG properties have been measured using a Tear and Fatigue Analyzer under various strain levels and temperatures. Microscopic analysis revealed that compounds with lower particle size and high structure CB showed better distribution and dispersion of CB throughout the whole matrix. Lower particle size with higher surface area displayed superior FCG resistance compared to the higher particle size CB. FCG of above compounds has also been studied at three different temperatures such as room temperature (25°C), 70°C, and 100°C. Significant increase in FCG rate was observed with increase in temperature due to the thermo‐oxidative degradation and reduction of strain‐induced crystallization.

Production and analysis of electrically conductive polymer – Carbon-black composites for powder based Additive Manufacturing

In laser powder bed fusion, micro-particles are selectively fused by a laser to produce parts, layer-by-layer. While this process offers a high freedom of design, the variety of commercially available materials, especially composites are limited. Conductive polymers blends, are very interesting for many applications, especially as sensors with freely definable shape. First, the amount of carbon-black needed to make the composite electrically conductive has to be determined; this limit is called percolation threshold (PT). The PT depends on many properties, such as particle size and shape of both polymer and carbon-black and will be determined experimentally. In this work, polypropylene is dry mixed with different types of micron sized carbon blacks. The PT and the conductivity is determined by means of impedance spectroscopy.Finally, layers are printed to evaluate the processability of the new composite.

Aqueous carbon black dispersions stabilized by sodium lignosulfonates

Six different sodium lignosulfonates with varying degrees of sulfonation (0.14–1.29 sulfonate groups per phenylpropane unit) and molecular weights (Mw = 6000–330,000 g/mol) were evaluated for their ability to disperse carbon black in aqueous media. Rheological and particle size measurements of carbon black dispersions indicated that lignosulfonates with low degree of sulfonation function as good carbon black dispersants. The dispersion efficiency did not correspond directly to the amount of lignosulfonate adsorbed on the surface of carbon black. The lignosulfonates have an ability to enhance the colloidal stability by electrostatic repulsion, and the likely mechanism of stabilization is a combination of electrostatic repulsion and steric hindrance.Graphical abstractEffect of lignosulfonates on carbon black particle size

Effect of Carbon Black on Rutting and Fatigue Performance of Asphalt

As an additive to improve the performance of asphalt binder, tire pyrolysis carbon black is gradually being used in road engineering, but the effect of carbon black (CB) with different particle sizes on asphalt modification remains to be further studied. In this study, three kinds of particle sizes and three kinds of contents of CB were used to modify asphalt, and different tests were conducted to research the high temperature performance and fatigue resistance of carbon black modified asphalt binder. It is found that the addition of CB can enhance the rutting resistance and medium temperature fatigue performance of virgin asphalt binder in general. However, for CB of 270 μm and 2.6 μm, its addition under certain contents lead to the decrease of high temperature performance and fatigue performance of the asphalt binder. For aged asphalt, the addition of CB decreases the rutting resistance and improves the fatigue resistance. The recommended content and particle size of CB are 2% and 2.6 μm. This study refines the complex effects of CB on asphalt properties, providing a reference for determining the size and content of CB in asphalt modification.

Chemical resistance of NR/SBR rubber blends for surfaces corrosion protection of metallic tanks in petrochemical industries

Abstract In this work, a series of Natural Rubber (NR)/Styrene Butadiene Rubber (SBR) blends were formulated to protect metallic petrochemical storage tanks from corrosive media. Therefore, these blends tested against a 10% HCl solution for 72 hr at room temperature. Blends series were prepared with different ratios of NR/SBR; 25/75, 30/70, 35/65, 40/60, 45/55, 50/50, and 55/45. Three types of carbon black (N-330, N-660, and N-762) were added individually to the 45/55 blend. Hardness, tensile strength, modulus, and elongation properties were tested before and after immersion in the 10% HCl attack media. All these mechanical properties decreased after immersion action accept hardness property. Up to 45 phr NR content, the hardness increased linearly independent on immersion action, but HCl immersion gives higher hardness values. Tensile strength increased up to 40 phr NR content with and without immersion and the immersion action decreased tensile values. The highest elongation value obtained with 35/65 blend with and without immersion. The 45 phr NR content gives the higher modulus, while the lowest value obtained with the 30 phhr content. For 45/55 blend, the hardness increased as the carbon black particle size decreased and immersion action gives higher hardness values. The tensile strength decreased linearly with the carbon black surface area, while with the medium surface area, the highest modulus and lowest elongation obtained.

Influence of the Carbon Black Dispersing Process on the Microstructure and Performance of Li‐Ion Battery Cathodes

The influence of the dispersion process and the carbon black (CB) particle size on the resulting structure and, hence, on the properties of lithium‐ion battery cathodes is investigated. N‐methyl‐2‐pyrrolidone‐based cathode slurries with 95.5 wt% (NCM622) and a high mass content (82.5 wt%) are processed in a planetary mixer PMH10 from NETZSCH with varying high‐speed stirrer tip speeds. Particle size analyses are carried out to measure the CB particle size at different time steps of the dispersion process. The resulting cathodes are characterized to determine mechanical and electrical properties. The microstructure of chosen electrodes is reconstructed and quantified by focused ion beam/scanning electron microscopy tomography and correlated with experimental data. In addition, discrete element method simulations are used for a deeper understanding of the dispersion process and breakage of CB aggregates. Correlations between process, structure, and properties of lithium‐ion battery cathodes are revealed.

Capacity Distribution of Large Lithium‐Ion Battery Pouch Cells in Context with Pilot Production Processes

The increasing relevance of automotive lithium‐ion battery cells spotlights the importance of economic production in a high quantity. In this context, production technology for large battery formats is of great relevance. Therefore, it is necessary to identify effects on important cell properties, and based on this, develop an understanding of the interaction between process parameters and product properties. Large‐format cells are not comprehensively examined, particularly, in a large sample size, analyzing cell properties in terms of distributed values. Hence, there is so far no statistical data concerning large‐format batteries and their distributed discharge capacity and self‐discharge. For this reason, and in contrast to other studies, the scope of this work is to investigate a large sample size of 79 industrial‐scale 9 Ah battery cells to ensure statistical relevance and generate distributed data of cell properties. For this purpose, a large number of cells are produced and extensively electrochemically investigated. Subsequently, the essential parameters are correlated with the electrode parameter of carbon black particle size. Hence, the foundation for this process–product–property relationship is laid.

Study on dispersibility of thermally stable carbon black particles in ink using asymmetric flow field-flow fractionation (AsFlFFF)

Carbon black (CB) has excellent chemical and physical properties including strong chemical strength and electrical conductivity. CB is widely used in various industries such as semiconductor, tire, rubber, ink, paint, toner and resin. When used in ink, as the CB particle size and the size distribution become smaller and narrower, respectively, they tend to be better dispersed, and the glossiness and stability of the ink increases.In the present study, asymmetrical flow field-flow fractionation (AsFlFFF) was employed to analyze the size distribution of CB particles used in ink. CB suspensions were prepared by dispersing CB powder in aqueous media containing copolymeric dispersing agents of hydrophobic (styrene) and hydrophilic (acrylic or maleic acid) monomers. Experimental parameters of AsFlFFF were optimized for analysis of the CB particles.Although the mean sizes obtained by AsFlFFF and dynamic light scattering (DLS) were in good agreements for those with narrow size distributions, DLS failed to distinguish among the CB suspensions having broad size distributions, whereas AsFlFFF differentiated them easily. Results indicated that the CB particles were dispersed better with copolymeric dispersing agents having an aromatic polymer with OH functionality than those with COOH functionality. It was also observed that, as the mean size of the CB particles decreases and the size distribution becomes narrower, the ink become thermally more stable.

Electrical and Tensile Properties of Carbon Black Reinforced Polyvinyl Chloride Conductive Composites

Conductive polymer composites are becoming more important and useful in many electrical applications. This paper reports on the carbon black (CB) reinforced polyvinyl chloride (PVC) conductive composites. Conductive filler CB was reinforced with thermoplastic PVC by compression molding technique to make conductive composites. The particle size of CB was measured, as it affects the electrical conductivity of the composites. Different types of CB-PVC compression-molded composites were prepared, using CB contents from 5 to 30 wt %. The electrical and tensile properties of these composites were studied and compared. Improved electrical properties were obtained for all CB-PVC conductive polymer composites compared to virgin PVC composite. However, the tensile properties of the CB-PVC composites increased up to 15 wt % CB loading, and then decreased, and elongation at break decreased with increasing CB loading. The structure of the CB, PVC and CB-PVC composites were studied by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopic analysis. ATR-FTIR spectra provide evidence of the formation of CB-PVC composites. The microstructural analyses showed a good dispersion of CB in PVC matrix.

Enhanced microwave processing of epoxy nanocomposites using carbon black powders

The conversion of electromagnetic energy into heat depends largely on the dielectric properties of the material being treated. Therefore, the knowledge of dielectric properties of the test specimen is required in order to understand the extent of curing using microwaves. In this study, a detailed investigation is carried out by considering a number of carbon black (CB) samples having particulate sizes in the range of 15–65nm. The dielectric properties of the synthesized CB/epoxy nanocomposites, before and after microwave curing, are measured using the advanced cavity perturbation method (CPM). It is observed that the CB/epoxy nanocomposite having smallest particulate size i.e., 15nm attains the maximum value of dielectric constant (εr′) and loss tangent (tanδ) of 10.79 and 0.05, respectively. These results indicate that the epoxy reinforced with the CB having least particulate size would interact more effectively with microwaves, which are confirmed by the experimental data showing that the nanocomposite with smallest CB particle size of 15nm requires the minimum curing time. The dielectric properties especially the loss factors of fully cured samples are found to decrease after curing indicating that the dielectric properties of post cured samples can provide an idea about the extent of curing. At last, thermal, mechanical and morphological analyses are also performed on all the microwave cured epoxy samples.

Effect of carbon black content and particle size on the phase evolution of aluminum oxy nitride (AlON)

In this work aluminum Oxy-nitride (γ-AlON) crystals were synthesized by Co-precipitation processing from Al(NO3)3 solution, magnesium acetate and nanosized carbon particles as the source of Al3+, Mg2+ and reducing agent, respectively. The effects of the nanosized carbon and Mg2+ content and particle size on the formation of AlON phase were investigated by means of XRD, SEM and EDS analysis. Our results indicated that AlON powder could be synthesized when the resultant precursors were calcined at 1700°C for 2h under flowing N2. Under optimal additional content of C (7.1wt%), the resultant AlON powders exhibited the primary particle size of about 2–4µm with a specific surface area of 3m2/g.

Influence of Particle Size of Carbon Black in Rubber Matrix on Its Vibration Characteristics

Influence of Particle Size of Carbon Black in Rubber Matrix on Its Vibration Characteristics