Search

Combining the several mixed phase structures and property profiles with a conductive, high aspect ratios nanofiller such as carbon nanotubes, graphene, and carbon black, specific morphological structures in melt spinning can be reached that offer much more potential for developing new functional fibers. Thus, understanding and controlling filler localization inside the developing phase morphology during melt spinning are the keys to the necessary structures. This work aimed to offer the possibility of producing fibers from electrically conductive polymer composites with a high filler concentration. First, the influence of different commercially available nanofillers, such as multi-wall carbon nanotubes (MWCNTs), graphene and carbon black on Polyamide 6 (PA6)-based nanocomposite melt-spun fibers were examined. Following the lab-scale melt spinning experiments, PA6/MWCNT-CB nanocomposite filaments containing 10 wt% nanofiller (each 5 wt%), were chosen for a pilot-scale bicomponent melt spinning process to investigate the influence of the nanocomposite core material feeding parameters on the properties of melt-spun fibers. The electrical conductivity decreased by half (from 3.13E-02 to 6.72E-03) when melt flow rate was increased from 3 g/min to 6 g/min. Scanning electron microscopy micrographs and thermal gravimetric analysis thermograms showed that the change in MFR values significantly affected the nanocomposite filaments' surface properties. [ABSTRACT FROM AUTHOR]

We have developed a carbon nanotube (CNT) pad to replace carbon black, which is essential for electric muscle stimulation (EMS) suits that can provide efficient exercise effects in a short time. The optimized CNT pad had 10 times lower concentration but showed 20 times lower resistance than the carbon black pad. In the case of the peak voltage indicating the EMS performance, it was confirmed that the CNT (4.0 wt%) was 25.9 V and the carbon black (40 wt%) was 6.5 V, which was about 4 times better. CNT added increased from 4.0 wt% to 10.0 wt%, and the peak voltage increased from 25.9 V to 26.8 V, but the output voltage was not significantly improved compared to the amount of CNT added. These experimental results are expected to show higher EMS properties than carbon black because carbon nanotubes and silicon are agglomerated to form a particle-like shape. [ABSTRACT FROM AUTHOR]

A cost-effective cement composite material has been developed for grounding systems, utilizing carbon black, carbon nanotubes, and steel fibers as conductive dopants. The electrical conductivity, mechanical properties, and fluidity of cement composites are investigated, and the synergetic mechanism of multiple conductive dopants in cement composites is revealed based on microscopic means. The results show that the combination of carbon black, carbon nanotubes, and steel fibers facilitates the establishment of efficient conductive networks in cement composites. The addition of 5 % carbon black, 0.3 % carbon nanotubes (by weight of cement), and 0.6 % steel fibers (by volume of composite) reduced the resistivity of the cement composite from 5568 Ω·cm to 310 Ω·cm after 28 days of curing. Then, it decreased to 267 Ω·cm after natural drying in laboratory environment until the 90th day. In addition, the resistivity of cement composites varies less than 5 % in environments ranging from −20°C to 50°C. Furthermore, the compressive and flexural strengths were 30.06 MPa and 6.17 MPa, and the flow diameter was 167 mm, which provided good mechanical strength and workability for conventional engineering applications. This paves an effective way for the further application of cement composites in grounding systems. • Electrically conductive cement composite was developed using carbon black, carbon nanotubes, and steel fibers. • Carbon black, carbon nanotubes, and steel fibers has synergistic combination effect to composite. • The distribution of carbon black, carbon nanotubes, and steel fibers within the cement composites is closely observed. • This combination of conductive dopants facilitates large-scale production of electrically conductive cement composites. [ABSTRACT FROM AUTHOR]

This paper investigated the influence of carbon black (CB) and carbon nanotube (CNT), used at 0–1%, by volume, on mechanical performance and piezoelectricity of 0–3 γ–C 2 S–based piezoelectric composite. The γ–C 2 S–based piezoelectric composite was prepared through carbonation of the proportioned mixture. Parameters d 33 , g 33 , and ε r were characterized with the CB and CNT additions. The influence of PZT size and volume on these parameters were also studied. Tested results showed that a greater PZT average size and volume significantly improved the d 33 , g 33 , and ε r values of γ–C 2 S–based piezoelectric composite given the increased contact among PZT particles. The use of 1.0% CB can lead to 50% and 265% enhancements in d 33 and ε r , respectively. Such improvements in d 33 and ε r values were 50% and 190%, respectively, with the addition of 0.3% CNT. This is attributed to the enhanced conductivity of γ–C 2 S–based piezoelectric composite, which can promote the poling of PZT particles. Moreover, the compressive strength of γ–C 2 S–based piezoelectric composite were improved by 12 and 3 MPa with the use of CB and CNT, respectively. In addition, the γ–C 2 S–based piezoelectric composite had 2–6 folds greater d 33 and ε r values given the similar CB and CNT contents relative to those of cementitious piezoelectric composite. Therefore, the use of CB and CNT can advance the development of γ–C 2 S–based piezoelectric composite with enhanced mechanical performance and piezoelectricity. [ABSTRACT FROM AUTHOR]

Carbon nanotube (CNT)-, surface-modified CNT: acid (–COOH) modified (MCNT) or base (–OH) modified (OHCNT), carbon black (CB)-filled fluoroelastomer (FE) and unfilled FE were prepared (CNT/FE, MCNT/FE, OHCNT/FE, CB/FE and FE). The thermal properties of the composites were assessed by TGA-GCMS and TGA and compared for all samples. TGA-GCMS results show that degradation products that obtained due to breakage of the CF2-CH2 bond (group A) and CF2-CF2 bond (group B) in base FE, obtained in lower temperatures and higher temperatures of TGA scan respectively, therefore CF2-CF2 bond is more thermally stable than CF2-CH2. For degradation products of group A and group B, the relative abundance decreased in the following orders respectively for all samples: CB/FE, CNT/FE, OHCNT/FE, FE, MCNT/FE; and MCNT/FE, OHCNT/FE, FE, CNT/FE, CB/FE. Therefore nanofillers and particularly surface-modified nanofillers produce less amount of group A degradation products and more amount of group B degradation products and therefore increase the thermal stability of the base FE. For all samples, the volatile degradation products that have the highest intensity are: (C6F7H2)•+, C4H6F+ and C6F11+ and the volatile degradation products are similar except for OHCNT/FE and MCNT/FE. TGA results also show that thermal stability reduced in the following orders in the lower temperature range and higher temperature range respectively: OHCNT/FE, FE, CB/FE, CNT/FE, MCNT/FE; and CB/FE, MCNT/FE, CNT/FE, FE, OHCNT/FE. Totally the results show that OHCNT/FE, MCNT/FE and CNT/FE can be used at high temperatures for making O-rings for very deep oil and gas drilling. [ABSTRACT FROM AUTHOR]

We report the design and simple spray coating fabrication process of a perfect absorber based on carbon nanotubes (CNTs) and carbon black particles with omnidirectional high absorption efficiency beyond 99.9% over the broad wavelength range from 400 nm to 20 μm. The carbon black particles are introduced into the CNT solution to form multi-scale all-carbon-based nanomaterials, effectively modifying the morphology of the sprayed layer to improve the light absorption. The promising absorption characteristics of the CNT–carbon black layer are attributed to not only the intrinsic optical properties of the carbon nanomaterials but also the unique surface nanostructures that efficiently trap light. In addition to serving as absorbers in the coating layer, the CNTs, more importantly, act as connectors between carbon black particles for absorber preparation at a large scale, which is the key to modifying the surface morphology. The all-carbon-based coating layer is also shown to be effective for solar thermal harvesting and self-cleaning function. The developed mixing method for CNTs and carbon black particles in solutions opens a new path for the realization of multi-functional sprayed layers based on CNTs and advances the technology of CNT coatings for scale-up to industry applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Two conductive carbon materials, one with a beaded-like structure (carbon black, ECP) and another with tube-like structure (functionalized multi-walled carbon nanotubes, FMWCNTs), were added into a poly(amide-imide) (PAI) matrix. Combining the advantages of ECP (good compatibility) and FMWCNT (high conductivity), the conductivity was improved from 3.7 S m−1 for PAI/FMWCNT polymer composites to 100 S m−1 for PAI/FMWCNT/ECP ternary conductive polymer composites, much higher than that of the sum of PAI/ECP and PAI/FMWCNT. The tensile strength increased from 40 to 70 MPa. The improved conductive and mechanical properties were mainly due to much more intensive conductive network produced in the PAI/FMWCNT/ECP ternary composites, which is useful for electron flow and stress spread. The number of hydrogen bond was increased by adding ECP into PAI/FMWCNT binary composites, and played an important role in forming the unique morphology as evident by Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD) measurements. These conductive composites have potential for flexible electronic applications. [ABSTRACT FROM AUTHOR]

Carbon-metal hybrid materials have shown promising performance as electrocatalysts for CO 2 reduction. Here, a comparative study of how different carbons supports influence this reaction is presented. The tested carbon supports were graphene oxide, multi-walled carbon nanotubes, carbon black and activated carbon while the metal complex selected was copper(II) phthalocyanine (CuPc). The CuPc supported on carbon nanotubes (CNT) and carbon black were found to give higher faradaic efficiencies (FE) for reduced carbon products, i.e. 66.3% and 81.8%, respectively compared to graphene oxide (0.0%) and activated carbon (12.8%). Amongst various sizes of CNT, long and thin tubes (in the range of 10–30 nm diameter size, 10–30 μm length) demonstrated higher FE (66.3%) relative to shorter and thicker ones (7.4%). Additionally, the novel use of CNT synthesized from post-consumer plastic waste was also explored as a potential carbon support material. It demonstrated comparable performance to commercial CNT in terms of FE (70.4%). Image 1 • Carbon nanotubes (CNTs) and carbon black were found superior for CO 2 reduction. • Long (10–30 μm) and thin (10–30 nm Ø) CNTs provided better faradaic efficiency. • The plastic waste derived CNTs were successfully applied as carbon support. • Waste derived CNTs resulted in comparable faradaic efficiencies to commercial CNTs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A ternary composite slurry by introducing AC, CB and CNT particles is proposed. • CNT and CB particles serve as bridging and filling effects, respectively. • A unique connection of charge percolation networks in AC/(CB + CNT) slurry was investigated. • Charge transfer enhanced mechanism in AC/(CB + CNT) slurry was explored by CFD simulation. • AC/(CB + CNT) slurry in FCDI exhibits a faster removal salt rate and lower molar energy consumption. Weak contact between activated carbon (AC) particles results in a poor conductivity for the electrode slurry, which limits the improved desalination performance in flow-electrode capacitive deionization (FCDI). Based on the bridging and filling effects of nanoparticles, we report a ternary composite slurry with multi-dimensional sized carbon particles by introducing the carbon nanotubes (CNT) and carbon black (CB) into AC-based slurry, namely AC/(CB + CNT) slurry. Further enhanced electrical conductivity relative to conventional pure AC slurry. By comparison analysis, FCDI system with the ternary carbon composite slurry had a faster average salt removal rate (ASAR) of 1.89 μmol cm−2 min−1 under at 1.2 V in a feed salinity of 2.0 g L−1, which is 3.27 1.92 and 1.46 times that of pure AC, AC/CB and AC/CNT slurry. In long-term operation (1800 min, U = 1.6 V), the AC/(CB + CNT) slurry exhibited a stable ASAR of 4.41 μmol cm−2 min−1 and maintained a charging efficiency (CE) of around 96% and molar energy consumption (E m) of 0.043 kWh mol−1. Electrochemical analysis and computational fluid dynamics (CFD) simulation further confirms that AC/(CB + CNT) slurry enable system with a point-to-line-to-surface connection morphology, which generates a robust charge percolation network with diverse pathway and facilitates the charge transfer. In summary, this study developed a facile strategy for increasing the slurry conductivity to provide a feasible approach in efficient desalination application. [ABSTRACT FROM AUTHOR]

Unidirectional Glass Fiber Reinforced Plastic (GFRP) laminates were prepared by inserting three-dimensional (3D) CNTs/carbon black film or CNTs/graphene oxide (GO) film into the laminates to improve the interlaminar performance. The effects of low-temperature cycles (35 cycles between −58 °C and room temperature (RT)) on the samples were investigated, and the damage caused to the reinforcement layer was directly detected by comparing the interlaminar images. By comparing the experimental results of the double cantilever beam (DCB) and end notch bending (ENF) test, the optimising effect of the new composite film (CNTs/carbon black film) on the interlaminar fracture toughness was verified. The results showed that the interlaminar fracture toughness of CNTs/GO film and CNTs/carbon black film in modes I (ENF test) and II (DCB test) was similar and superior to that of CNTs film. Regarding the effect of the low-temperature cycles on the samples, the change of CNTs/carbon black film and CNTs/GO film is also lower than that of CNTs film. Finally, the matrix interface and failure mechanisms of the interlaminar reinforcement were investigated by scanning electron microscope (SEM). • The superiority of the structure was verified. • The effects of the low-temperature cycle on the samples were investigated by low-temperature treatment. • Damage caused by the low-temperature cycle to the reinforcing layer was directly proved by comparing the interlaminar images. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Fatigue property of CNT/NR and CB/NR composites with similar hardness was compared. • CNT/NR exhibited excellent fatigue resistance at low filler content and strain. • Fatigue property of CB/NR increased with CB content. • Fatigue mechanism was proposed from hysteresis, SIC and stress concentration. Fatigue property is of great importance for the security and reliability of rubber products. The fatigue performance of natural rubber (NR) filled with carbon nanotube (CNT) and carbon black (CB) with different content but similar hardness was investigated. Results indicated that CNT/NR exhibited the best fatigue performance at low CNT content and fatigue strain, while the crack growth was accelerated with the increase of CNT content and strain. As for CB/NR, the fatigue resistance increased with CB content and strain. The different fatigue performance of NR composites was discussed from the perspective of hysteresis, strain-induced crystallization, and stress concentration effect. [ABSTRACT FROM AUTHOR]

Efficient and harmless disposal of landfill leachate has attracted increasing attention. In this study, the bio-electro-Fenton method was investigated and developed to degrade the organic compounds in landfill leachate by hydroxyl radical oxidation. The optimal operational parameters (i.e., pH and external voltage) of the bio-electro-Fenton system were detected. Under the conditions of pH 2, 0.6 V, the highest total chemical oxygen demand (COD) decrement efficiency was obtained (about 70%), with apparent removal constant at 6 h (k app-6h) of about 0.12 h−1. Subsequently, to further increase the degradation efficiency, functionalized carbon black and functionalized carbon nanotube (FCNT) were prepared as catalysts for the cathode electrode modification. With 0.4 mg/cm2 FCNT coated on the cathode electrode, 91.3% of the organic compounds were degraded, remaining only 84 mg/L COD (k app-6h = 0.24 h−1). In all the reactors, the COD was mainly decreased in 0–6 h, contributing to over 68% of the total degradation efficiency. In the bio-electro-Fenton system, the bio-anode electrode could enhance H 2 O 2 production and the conversion between Fe2+ and Fe3+ by strengthening electrons generation and transportation via the oxidation of organics by biofilms (dominant with Geobacter) covered on the carbon brush. [Display omitted] • Refractory organics in leachate could be degraded by bio-electro-Fenton process. • 70% COD in leachate was degraded under pH 2 and 0.6 V conditions in MEC system. • 91.3% COD in leachate was degraded when cathode electrode was modified by FCNT. • COD was mainly degraded in 0–6 h, contributing to over 68% of the total efficiency. • Biofilm (mainly Geobacter) could enhance electrons generation and transportation. [ABSTRACT FROM AUTHOR]

Here we report a carbon-black-modified g- C3N4 nanocomposite prepared by a convenient method and its photocatalytic performance, which was compared with other carbon-material-, carbon nanotube ( CNT)-, C60-, and graphene ( GR)-modified g- C3N4 nanocomposites. X-ray diffraction, N2 adsorption, UV-vis spectroscopy, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, and photoluminescence were used to characterize the prepared composite material. The results reveal that incorporating g- C3N4 with carbon materials decreases the bandgap and the electron-hole recombination rate of the prepared catalysts. No significant difference was observed in the structural and optical properties among these four series of carbon-material-modified g- C3N4 nanocomposites. Carbon-based materials cannot act as visible-light sensitizers but they can facilitate the separation and transport of photogenerated carriers. These composites obey a tentative reaction mechanism similar to rhodamine B ( RhB) photocatalytic degradation. Carbon-black-modified g- C3N4 exhibits comparable activity and stability as those of GR-modified g- C3N4 , which is better than the modification by C60 and CNTs. Compared to CNTs, GR, and C60 , carbon black is a cheap and effective carbon source with excellent photocatalytic performance for the preparation of carbon material/g- C3N4 nanocomposites. [ABSTRACT FROM AUTHOR]

To improve the electrochemical performance of Na 2 Li 2 Ti 6 O 14 , carbon black (CB), graphene (GN) and carbon nanotube (CNT) are introduced to fabricate high conductive Na 2 Li 2 Ti 6 O 14 /CB, Na 2 Li 2 Ti 6 O 14 /GN, Na 2 Li 2 Ti 6 O 14 /CNT and Na 2 Li 2 Ti 6 O 14 /CB/GN/CNT by a solid state method. It can be found that only CNT forms a complete three-dimensional conductive network which embeds the randomly distributed Na 2 Li 2 Ti 6 O 14 particles, leading to an improvement of electronic conductivity. The results of cyclic voltammetry, electrochemical impedance spectroscopy and charge–discharge tests reveal that Na 2 Li 2 Ti 6 O 14 /CNT obtains the lowest redox polarization and the highest peak current among all the five samples. As a result, Na 2 Li 2 Ti 6 O 14 /CNT shows the best cycling and rate performances among all the five samples. It reveals a charge capacity of 111.4 mAh g −1 at 100 mA g −1 , 110 mAh g −1 at 200 mA g −1 , 103.9 mAh g −1 at 300 mA g −1 and 98.9 mAh g −1 at 400 mA g −1 . For comparison, bare Na 2 Li 2 Ti 6 O 14 only displays a charge capacity of 89.9 mAh g −1 at 100 mA g −1 , 79.7 mAh g −1 at 200 mA g −1 , 73.7 mAh g −1 at 300 mA g −1 and 69.4 mAh g −1 at 400 mA g −1 . It indicates that the introduction of CNT is more effective to improve the performance of Na 2 Li 2 Ti 6 O 14 than CB, GN and CB/GN/CNT. [ABSTRACT FROM AUTHOR]

As a novel anode material for lithium-ion batteries, Pb(NO3)2can deliver an initial discharge capacity as high as 1310.8 mAh g−1. However, its capacity retention is poor upon repeated cycles. In this work, carbon black (CB), graphene (GN) and carbon nanotube (CNT) are used as conductive additives to fabricate Pb(NO3)2/CB, Pb(NO3)2/GN and Pb(NO3)2/CNT, respectively. It is observed that CB and GN fail to form uniform three-dimensional conductive network for Pb(NO3)2. As a result, Pb(NO3)2/CB and Pb(NO3)2/GN do not show obviously improved electrochemical properties compared to bare Pb(NO3)2. For comparison, CNTs provide cross-linking conductive cages for Pb(NO3)2particles. It can be found that CNT coating can significantly enhance the electrochemical property of Pb(NO3)2. Pb(NO3)2/CNT reveals a reversible charge capacity of 495.2 mAh g−1after 45 cycles at a current density of 50mAg−1, which is much higher than that of bare Pb(NO3)2(227.4 mAh g−1), Pb(NO3)2/CB (278.0 mAh g−1), Pb(NO3)2/GN (327.2 mAh g−1). Even cycled at 200mAg−1, Pb(NO3)2/CNT can maintain a reversible lithium storage capacity of 411.7 mAh g−1. All these results suggest that Pb(NO3)2/CNT is a promising anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Polymer composites containing conductive fillers that utilize the piezoresistive effect can be employed in flexible pressure sensors. Depending on the filler used, different characteristics of a pressure sensor such as repeatability, sensitivity, and hysteresis can be determined. To confirm the variation of the pressure sensing tendency in accordance with the dimensions of the filler, carbon black (CB) and carbon nanotubes (CNTs) were used as representative 0-dimension and 1-dimension conductive fillers, respectively. The piezoresistive effect was exploited to analyze the process of resistance change according to pressure using CB/PDMS (polydimethylsiloxane) and CNT/PDMS composites. The electrical characteristics observed for each filler were confirmed to be in accordance with its content. The pressure sensitivity of each composite was optimized, and the pressure-sensing mechanism that explains the difference in sensitivity is presented. Through repeated compression experiments, the hysteresis and repeatability of the pressure-sensing properties were examined. [ABSTRACT FROM AUTHOR]

A two-step analytical model based on a percolation network model and electron tunneling theory has been developed to predict the electrical resistivity and percolation threshold of a hybrid nanocomposite system comprising carbon black (CB) and carbon nanotube (CNT). The nanostructure of a tunneling network consisting of CNT and CB agglomerates has been generated to study the effects of various parameters on electrical conductivity. Electron tunneling is the primary mechanism for electrical percolation, which is incorporated into the model by considering the effective tunneling distance of CNTs. Later, a percolation network model is introduced to evaluate the electrical properties of the hybrid nanocomposite. Our results indicate that a high level of alignment leads to a significant decrease of the percolation threshold with an increase in conductivity, while a low CB volume fraction with low intrinsic electrical conductivity degrades the percolation and overall conductivity. Our results also reveal that the addition of CB as a second filler in a hybrid nanocomposite leads to improvements in conductance and percolation threshold. Analytical results show that the current model agrees well with existing experimental data, which reveals that tunneling and percolation are the dominant mechanisms for transition behavior in electrical conductivity. • The electrical resistivity behavior of a hybrid nanocomposite has been modeled. • A greater improvement in conductance is achieved by the incorporation of hybrid CB/CNT filler. • Aspect ratio, maximum orientation angle, and agglomerate size are effective factors. • Large CB agglomerate surface area facilitates the establishment of percolation paths. • Model predictions agree well with experimental data. [ABSTRACT FROM AUTHOR]

Ultrahigh power is needed beyond the state-of-the-art supercapacitors for emerging technologies. Towards this goal, nanostructured carbon materials have been extensively studied but unfortunately encountered with the difficulty in practical applications, which is largely due to their limited packing densities. In this work, we utilize a highly dense commercial activated carbon to develop high-rate nanocomposite electrodes and ultrahigh-power supercapacitors by compositing activated carbon with carbon nanomaterials, including zero-dimensional carbon black, one-dimensional carbon nanotube, and two-dimensional graphene. Enabled by the mixed packing (forming a unique point-to-line-to-plane contact morphology), diverse electrical conduction (forming a well-interconnected three-dimensional electrical conduction network), and varied porosity (forming a well-defined hierarchical porous structure) from these multiple constituents, the optimized quaternary nanocomposite electrode possesses a good combination of facilitated electron transport and enhanced ion diffusion and thus a twofold higher rate capability (capacitance retention: 83.3% vs. 28.9% at 80 A g−1 vs. 0.5 A g−1), twofold higher power density (84.1 kW kg−1 vs. 41.9 kW kg−1), and superior high-rate cycling stability (capacitance retention: 80.2% vs. 65.9% after charge/discharge at 10 A g−1 for 30,000 cycles) than its conventional activated carbon counterpart, while its high volumetric power density (50.5 kW L−1) strengthens its practical usefulness. Our research represents a novel approach to fabricate commercially available materials into practically useful ultrahigh-power supercapacitors at low cost, which may also be employed as a universal strategy to develop high-performance nanocomposites to benefit a wider range of application technologies. [ABSTRACT FROM AUTHOR]

We report on a hybrid carbon-based composite for zero temperature coefficient of resistance (TCR) heating element, forming edge-island type composite comprised of carbon nanotubes (CNTs) and carbon blacks (CBs) with a polydimethylsiloxane. The island-shaped CB composite is placed between a copper connection electrode and the CNT composite, acting as both a buffer and distribution layer against current flow for a zero TCR. The degree of control over this zero TCR was characterized by examining the thickness ratio between the CNT and CB layers. The optimized edge-island composite structure showed a constant normalized resistance (with <3% deviation) to 200 °C with a rapid heating property. This edge-island composite structure could be widely used for heat-related or sensor applications, solving safety, and accuracy issues. [ABSTRACT FROM PUBLISHER]

• Self-sensing capability of ECC with different carbon-based materials was assessed. • Carbon fibers (CF), carbon nanotubes (CNT) and carbon black (CB) were used. • Specimens cured for 7, 28, 90 and 180 days were used for self-sensing assessment. • Tests were performed under compression, splitting tension and four-point bending. • Self-sensing is valid for all curing ages and under different loading conditions. Self-sensing capability of 7-, 28-, 90- and 180-day-old Engineered Cementitious Composites (ECC) incorporated either with carbon fibers (CF/ECC-CF) at micro-scale or multi-walled carbon nanotubes (CNT/ECC-CNT) and carbon black (CB/ECC-CB) at nano-scale were investigated herein. Mechanical properties (compressive strength, splitting tensile strength/deformation, flexural strength/deformation) of different-age mixtures were evaluated. Control mixture (ECC-Control) without any carbon-based material was also produced and tested for comparison. Depending on the loading condition, equipment utilizing either direct current (DC) or alternating current (AC) was used for self-sensing assessments. Results showed that carbon-based materials generally improve the mechanical properties of ECC-Control specimens depending on the type of carbon-based materials, specimens' age and loading conditions. All specimens sensed different types of damage except 180-day-old ECC-Control specimens loaded under uniaxial compression and splitting tension due to abrupt increments in impedance results exceeding the limits of testing device which revealed the importance of presence of electrically-conductive materials for achieving enhanced self-sensing capability independent of aging, testing configuration/equipment, loading conditions and microcrack characteristics. CF is the best to improve self-sensing capability of ECC-Control specimens for all ages and loading conditions. Self-sensing performances of ECC-CNT and ECC-CB are comparable and utilization of nano-size carbon-based materials is suggested in cases where reversibility in self-sensing is needed. [ABSTRACT FROM AUTHOR]