Conductive Carbon Black Research Articles

Effect of blend ratio on the morphology and electromagnetic properties of nanoparticles incorporated natural rubber blends

Abstract Natural rubber/epoxidized natural rubber (NR/ENR) composites with 30 wt% conductive carbon black (CCB) were prepared by tow-roll mechanical mixing. Influences of NR/ENR blend ratios on the morphology and electromagnetic properties of CCB/NR/ENR composites were studied. Thermodynamic and morphological analysis indicated that co-continuous NR/ENR blend favored the formation of CCB network, providing the composites with superior electromagnetic properties. Electrical conductivity, dielectric loss and reflection loss over C-band (8–12 GHz) of CCB/NE/ENR composite were found to be a function of NR/ENR ratio, and reached the optimum value of 0.34 S/m, 0.31 and −23.58 dB when NR/ENR was 70/30 (wt./wt.), respectively. A morphology-promoted electromagnetic wave attenuation mechanism was proposed.

Exploring the Combined Effect of Electron Beam and Conductive Carbon Black on the Mechanical, Dynamic Mechanical, Thermal, and Electrical Properties of Ethylene Acrylic Elastomer

ABSTRACTThe electron beam-crosslinked and conductive carbon black-reinforced ethylene acrylic elastomer composites have been developed for various applications. The inter-connectivity of conductive carbon black agglomerates are clearly observed from the high-resolution transmission electron photo micrographs. The tensile strength of the composites has remarkably increased with increasing conductive carbon black loading up to 350 radiation dose. The dielectric permittivity (ϵ′) and AC conductivity (σac) increase with an increase in conductive carbon black loading. The electron magnetic shielding interference of the developed composites has been measured using X-band frequency range, and the electron magnetic shielding interference increases with an increase in conductive carbon black loading.

Modifying membrane anode in a microbial fuel cell to improve removal of gaseous ethyl acetate without reducing generation of electricity

An S-type flow-field pipe-microbial fuel cell (SFP-MFC) was developed to remove ethyl acetate (EA) from an air stream. Features of the SFP-MFC included the use of polyvinyl alcohol and a membrane electrode assembly (PVA-MEA) as the gas diffusion membrane and proton exchange membrane (PEM), which separated the anode from the cathode. The performance of the SFP-MFC system was evaluated with an empty bed residence time (EBRT) of 14.35s and an organic loading rate of 63−3700g/m3/h, with or without the modification of the PVA-MEA electrode using conductive carbon black (CCB). Experimental results revealed that the maximum elimination capacity (EC) and voltage were 2288g/m3/h and 330mV, respectively, which were obtained when the PVA-MEA was modified using CCB. The PVA-MEA that was modified with CCB exhibited a 90% higher EA elimination capacity than the PVA-MEA without CCB modification. Moreover, the SFP-MFC system exhibited buffering at high organic loading, reducing the microbial inhibition by toxic pollutants. The maximum EC and EBRT of the modified SFP-MFC were 3−10 times higher and 2−12 times shorter, respectively, than those of biotrickling filters.

Size and shape of graphene layers in commercial carbon blacks established by Debye refinement

The size and the shape of graphene layers in commercial conductive carbon blacks, Super P and Super S, have been determined from powder X-ray diffraction data. Using a refinement procedure based on the fundamental diffraction equation of Debye, it is shown that the ordered regions within the layers of both materials are of elliptical shape, curved in a cylindrical fashion along the longer axis of the ellipse. The regions are greater in Super P, ellipse axes 5.4 and 2.2 nm, than in Super S, 4.6 and 2.1 nm, and less curved (curvature radii 12.7 and 11.7 nm, respectively). There is no crystallographic registry between layers, which are equidistantly stacked into concentric groups of six or seven, on average.

Poly(vinylidene fluoride) Nanocomposites with Simultaneous Organic Nanodomains and Inorganic Nanoparticles

Nanostructured polymeric dielectric composites, based on poly(vinylidene fluoride) (PVDF), conductive carbon black (CB), and an unsaturated ionic liquid (IL), 1-vinyl-3-ethylimidazolium tetrafluoroborate ([VEIM][BF4]), were fabricated by melt blending and electron beam irradiation (EBI) methods. Our strategy forms simultaneous double nanophases in the PVDF matrix, that is, homogeneously dispersed CB nanoparticles and organic PVDF-g-IL nanodomains. The organic nanodomains were produced by microphase separation of the PVDF-g-IL chains from the PVDF matrix at melt state in the electron beam (EB) irradiated PVDF/IL-CB nanocomposites. Furthermore, the CB nanoparticles were fully adhered with these nanodomains, and novel structures with nanodomains@CB nanoparticle were achieved. Such nanodomains@CB nanoparticle structures showed a synergetic nucleating effect on the PVDF crystallization and led to the formation of dominant nonpolar α phases in the nano-PVDF/IL-CB composites. Because of the nanodomains adhesion ...

G-C3N4/conductive carbon black composite as Pt-free counter electrode in dye-sensitized solar cells

The composites of g-C3N4 and conductive carbon black (CCB) were prepared by a simple ball-milling process and explored as the counter electrode for dye-sensitized solar cells (DSCs). The enhanced electrocatalytic activity for I3− reduction can be demonstrated when CCB was incorporated into g-C3N4. The charge-transfer resistance of g-C3N4/CCB (1:1, mass ratio) composite electrode was 2.4Ωcm2, which is much lower than those of the individual g-C3N4 and CCB electrodes, indicating predominant synergistic effect of g-C3N4 and CCB in electrocatalytic activity. Under illumination of 100mWcm−2, the DSC with g-C3N4/CCB (1:1) composite counter electrode achieved a conversion efficiency of 5.09%, which is comparable to that of the cell with Pt counter electrode.

Reinforcement of Multiwalled Carbon Nanotube in Nitrile Rubber: In Comparison with Carbon Black, Conductive Carbon Black, and Precipitated Silica

The properties of nitrile rubber (NBR) reinforced by multiwalled carbon nanotube (MWCNT), conductive carbon black (CCB), carbon black (CB), and precipitated silica (PSi) were investigated via viscoelastic behavior, bound rubber content, electrical properties, cross-link density, and mechanical properties. The filler content was varied from 0 to 15 phr. MWCNT shows the greatest magnitude of reinforcement considered in terms of tensile strength, modulus, hardness, and abrasion resistance followed by CCB, CB, and PSi. The MWCNT filled system also exhibits extremely high levels of filler network and trapped rubber even at relatively low loading (5 phr) leading to high electrical properties and poor dynamic mechanical properties. Although CCB possesses the highest specific surface area, it gives lower level of filler network than MWCNT and also gives the highest elongation at break among all fillers. Both CB and PSi show comparable degree of reinforcement which is considerably lower than CCB and MWCNT.

Isothermal and Non-Isothermal Crystallization Kinetics of Conductive Polyvinylidene Fluoride/Poly(Ethylene Terephthalate) Based Composites

This work deals with isothermal and non-isothermal crystallization kinetics of electrically conductive polyvinylidene fluoride/poly(ethylene terephthalate) (PVDF/PET) based composites. It completes our previous work in which we related the crystallinity of these conductive PVDF/PET based composites to their through-plane resistivity [1]. Isothermal crystallization was described using the logarithmic form of the Avrami equation and it was observed that the crystallization rate of the PVDF phase inside the composite became slower compared to that of neat PVDF. In non-isothermal crystallization, the Avrami exponent of PVDF phase did not show any noticeable variation; however, that of PET phase, which contains the major part of the conductive carbon black (CB) and graphite (GR) additives, showed an evident decrease compared with neat PET. It was also observed that, at the same cooling rate, the crystallization rate of PVDF and PET phases inside the composite was slower than that of neat PVDF and PET.

Fish embryo toxicity assessment of o-dianisidine in Clarias gariepinus and its electrochemical treatment in aquatic samples using super conductive carbon black

The present study tested fish embryo toxicity (FET) ofo-dianisidine (o-dian) on African catfish (Clarias gariepinus) and its electrochemical treatment through electro-oxidation of real aquatic samples for the first time.

An experimental investigation of the effect of strain on the electrical conductivity of a shape memory polymer

A thermally triggered shape memory polymer (SMP) was prepared by blending electrically conductive carbon black (CB) into the resin prior to curing. The CB filled composite can then be activated through resistive heating. With the aim of using such SMPs in reconfigurable structures and/or actuators, the effect of strain on the conductive nature of the SMP composite was investigated. The study has specifically focused on changes to conductivity in, i) the transverse direction during tensile elongation to assess the impact of the Poisson effect, and ii) in samples deformed in compression. The dynamic response characteristics of the electrically activated SMP were also tested to assess the feasibility of using the composite in tunable vibration damping applications. Findings have shown that the pattern of changes in the transverse conductivity, which is marked by an increase-decrease-increase sequence, resembles that seen in the axial direction. SEM imaging of the samples was performed along the axial and transverse axes of deformation and shows no anisotropy in the CB filler distribution. To demonstrate potential uses of a conductive SMP in the sub-Tg temperature range, a discussion of a vibration damping application has been included.

Quality factor of Melt blend processed polypropylene/poly (acrylonitrile-butadiene-styrene)/ conducting carbon black blends

Polypropylene(PP)/Acrylonitrile-butadiene-styrene (ABS) was prepared with melt blending technique by using twin screw extruder as a function of conducting carbon black (CCB) loading. Two compatabilizer such as polypropylene grafted maleic anhydride (PP-g-MA) and styrene/ether-co-butadiene/styrene (SEBS-g-MA) are used (5wt % each) to obtain the refined morphology. The structural analysis has been done by using X-Ray diffraction (XRD). The variation in interplaner spacing disclosed to the improved electrical properties. The electrical analysis confirm that the Quality (Q) factor and dissipation factor increases as a function of CCB loading. The modified blend CCB (for 10 %) loading offer the very high Q factor (18 × 103). The optimization of Q-factor achieved as a function of CCB loading. This investigation may be suitable for the coating and barrier application in marine and communication domain.

Paints and Coatings Drive the Conductive Carbon Black Market

Paints and Coatings Drive the Conductive Carbon Black Market

Effect of plasticizer on the electrical, thermal, and morphological properties of carbon black filled poly(propylene)

Poly(propylene) (PP)/carbon black (CB) composites are melt‐blended in a Brabender mixer with varying CB content. With the special‐grade conductive CB, the surface resistivity of PP/CB composite was reduced by 13 orders of magnitudes by increasing the CB content from 0 to 15 wt%. The plasticizer poly(ethylene glycol) di‐methyl ether (PEGDME) is used (0–5 wt%) to improve the dispersion of the CB in the polymer matrix and to reduce the surface resistivity of the composites. But the PEGDME plasticizer used here has no positive effect on the surface resistivity of the composites; in fact, it enhances the surface resistivity value by one order of magnitude at higher concentration (5 wt%). The scanning electron microscopy (SEM) pictures indicate that the presence of foreign material (plasticizer) especially at higher concentration disrupts the continuous carbon network inversely affecting the conductivity values. Finally, the optimization of the input variables (CB and PEGDME loading) is done using the design of experiment approach. POLYM. COMPOS., 38:2472–2479, 2017. © 2015 Society of Plastics Engineers

Construction of an Interconnected Nanostructured Carbon Black Network: Development of Highly Stretchable and Robust Elastomeric Conductors

In the present work, a strong filler–filler network of conductive carbon black was strategically established in an elastomer matrix, which leads to a unique combination of electrical and mechanical properties. The novelty of our composites was the development of a strong percolated morphology of nanostructured conducting carbon black particles by the incorporation of relatively large nonreinforcing spherical silica particles, inside the soft elastomer matrix. This technique allowed us to fabricate solution styrene butadiene rubber (S-SBR) composites with outstanding electrical conductivity of 40 S/m, tensile strength ∼10 MPa, and extensibility up to 200%. Furthermore, the electrical conductivity was strain-independent up to 50% elongation strain. The electrical conductivity was found to be unaltered after 2000 loading–unloading cycles. This is the first ever report of a robust elastomeric system with such high electrical conductivity where all the basic ingredients used were selected from well-known comme...

Contactless microfluidic pumping using microchannel-integrated carbon black composite membranes.

The ability to pump and manipulate fluid at the micron-scale is a basic requirement for microfluidic platforms. Many current manipulation methods, however, require expensive and bulky external supporting equipment, which are not typically compatible for portable applications. We have developed a contactless metal electro-osmotic micropump capable of pumping conductive buffers. The pump operates using two pairs of gallium metal electrodes, which are activated using an external voltage source and separated from a main flow channel by a thin micron-scale polydimethylsiloxane (PDMS) membrane. The thin contactless membrane allows for field penetration and electro-osmotic flow within the microchannel, but eliminates electrode damage and sample contamination commonly associated with traditional DC electro-osmotic pumps that utilize electrodes in direct contact with the working fluid. Our previous work has demonstrated the effectiveness of this method in pumping deionized water. However, due to the high resistivity of PDMS, this method proved difficult to apply towards manipulating conductive buffers. To overcome this limitation, we fabricated conductive carbon black (CB) powder directly into the contactless PDMS membranes. The increased electrical conductivity of the contactless PDMS membrane significantly increased micropump performance. Using a microfluidic T-channel device and an electro-osmotic flow model, we determined the influence that CB has on pump pressure for CB weight percents varying between 0 and 20. The results demonstrate that the CB increases pump pressure by two orders of magnitude and enables effective operations with conductive buffers.

Electrical, dielectric, and dynamic mechanical properties of conductive carbon black/epoxidized natural rubber composites

Electrically conductive epoxidized natural rubber filled with conductive carbon black was prepared. The AC conductivity ( σAC), dielectric constant ( ɛ′), loss factor (tan δ*) and dynamic mechanical properties of the composites were studied. It was found that the epoxide groups in epoxidized natural rubber molecules positively contributed to AC conductivity, dielectric constant, and tan δ* of the composites. Especially, the composite with epoxidized natural rubber containing 50% mol epoxide (epoxidized natural rubber–50) showed better electrical and dynamic mechanical properties than the composites with epoxidized natural rubber–25 or NR. The effects of conductive carbon black loading level on electrical conductivity and dielectric constant of the epoxidized natural rubber–50/conductive carbon black composites was also studied. The percolation threshold was found at very low content of conductive carbon black at volume fraction of 0.07 with the critical exponent value 2.04. Furthermore, the glass transition temperatures of epoxidized natural rubber–50/conductive carbon black composites were higher than those of epoxidized natural rubber–25/conductive carbon black or NR/conductive carbon black composites, and increased with conductive carbon black content.

Preparation and structural evolution of well aligned-carbon nanotube arrays onto conductive carbon-black layer/carbon paper substrate with enhanced discharge capacity for Li–air batteries

This study demonstrates the preparation of well aligned-carbon nanotube (WA-CNT) arrays onto a carbon paper substrate with a conductive carbon-black layer by the catalyst seed-impregnated chemical vapor deposition method. The prepared WA-CNT arrays were then characterized by scanning electron microscopy for different growth temperatures, standard linear velocities of feed vapors, and ferrocene-to-xylene ratios in the feed vapors. Results indicate that the optimal WA-CNT arrays of length 40–50μm and diameter 30–40nm were obtained at the growth temperature range of 750–800°C, standard linear velocity of 1.40cms−1, and ferrocene-to-xylene molar ratio of 1:50–1:30. These results provide new insights into the growth mechanism of CNT arrays, which involves cross-coupling of chemical reaction and mass transfer based on reaction engineering theory. The samples prepared in the study can be used as catalyst supports in air electrodes considering their three-dimensional porous structure, approximately linear channel, controllable length and diameter distribution, and excellent CNT conductivity. Electrochemical measurement indicated that the WA-CNT arrays/carbon-black layer/carbon paper substrate composites achieved relatively high discharge capacity of 2930mAhg−1(CNTs) at a current density of 0.05mAcm−2 in Li–air batteries, which far exceeded other carbonaceous materials in Li–air batteries.

Prediction of Microwave Absorption Behavior of Grading Honeycomb Composites Based on Effective Permittivity Formulas

Microwave absorbing honeycomb composites with grading coating thickness are prepared by impregnation of aramid paper frame within water solutions of conductive carbon blacks. Based on effective medium method, grading impedance in the composites can be theoretically expressed by a linear approximation of the inversely tapered effective permittivity at wave propagation direction, which provides a feasible way to optimize the design of microwave absorbing honeycomb structures. The consistent result of calculations and experimental measurements for positive impedance grading design confirms the broadband absorption effect in high frequencies.

Effects of multi‐walled carbon nanotubes and conductive carbon black on electrical, dielectric, and mechanical properties of epoxidized natural rubber composites

The influence of multi‐walled carbon nanotubes (MWCNTs) and conductive carbon black (CCB) on cure, electrical, dielectric, and mechanical properties of epoxidized natural rubber (ENR) composites was investigated. It was found that short MWCNTs (S‐MWCNTs) with low loading significantly affected the cure characteristics in a way similar to high loading of CCB. Moreover, the ENR/S‐MWCNTs composites exhibited high AC conductivity, dielectric constant, and dielectric loss tangent (tan δ) compared to the ENR/CCB and ENR/L‐MWCNTs (long MWCNTs) composites. In addition, the S‐MWCNTs composites showed the lowest percolation threshold concentration, defined as the lowest loading to form conductive paths in the insulating ENR matrix. This might be attributed to the comparatively high interfacial polarization, with good dispersion and distribution, of the S‐MWCNTs in ENR matrix. These characteristics were confirmed by TEM imaging and by a high bound rubber content, corroborating strong filler–rubber interactions in the ENR/S‐MWCNTs composites. However, the L‐MWCNTs composites showed the lowest electrical and other related properties, despite the highest aspect ratio and specific surface area of this filler. This might be because of the flocculation of nanotubes by mutual entanglement, leading to a poor uneven distribution in the ENR matrix. POLYM. COMPOS., 38:1031–1042, 2017. © 2015 Society of Plastics Engineers

Carbon-based nanofillers/Poly(butylene terephthalate): thermal, dielectric, electrical and rheological properties

The influence of distinct carbon based nanofillers: expanded graphite (EG), conducting carbon black (CB), thermally reduced graphene oxide (TRGO) and multi-walled carbon nanotubes (CNT) on the thermal, dielectric, electrical and rheological properties of polybutylene terephthalate (PBT) was examined. The glass transition temperature (Tg) of PBT nanocomposites is independent of the filler type and content. The carbon particles act as nucleation agents and significantly affect the melting temperature (Tm), the crystallization temperature (Tc) and the degree of crystallinity of PBT composites. PBT composites with EG show insulating behaviour over the tested concentration range of 0.5 to 2 wt.-% and hardly changed rheological behaviour. CB, CNT and TRGO induce electrical conductivity to their particular PBT composites by forming a conducting particle network within the polymer matrix. CNT reached the percolation threshold at the lowest concentration (<0.5 wt.-%), followed by TRGO (<1 wt.-%) and CB (<2 wt.-%). With the formation of a particle network, the flow behaviour of composites with CB, CNT and TRGO is affected, i.e., a flow limit occurs and the melt viscosity increases. The degree of influence of the carbon nanofillers on the rheological properties of PBT composites follows the same order as for electrical conductivity. Electrical and rheological results suggest an influence attributed to the particle dispersion, which is proposed to follow the order of EG < < CB < TRGO < CNT.