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Tryptophan, an essential amino acid playing a pivotal role in various biological processes, stands as a focal point in our investigation. In this study, we introduce a groundbreaking electrochemical sensor that integrates a nanocomposite comprising carbon black (CB) and zinc oxide nanoparticles (ZnO-NPs) for the selective detection of L-tryptophan (Trp). The synthesis of ZnO-NPs, accomplished through the sol-gel technique, was meticulously characterized using XRD, FTIR, and UV-visible methods to unveil their structural and optical properties. The construction of the sensing electrode involved the deposition of a CB/ZnO-NP nanocomposite onto a glassy carbon electrode (GCE) utilizing the drop-coating method. Rigorous evaluation and analysis of the modified glassy carbon electrode were carried out through scanning electron microscopy (SEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The resulting CB/ZnO-NPs/GCE electrode exhibited an augmented surface area and outstanding electrocatalytic activity. Significantly, the CB/ZnO-NP sensor displayed remarkable analytical performance for tryptophan detection over an extensive concentration range from 0.01 to 100 µmol.L−1, featuring a low detection limit of 0.017 µmol.L−1. Moreover, the proposed electrochemical sensor exhibited notable selectivity, specifically targeting tryptophan, emphasizing its potential for diverse analytical applications. This work not only expands our understanding of tryptophan detection but also offers a highly sensitive and selective tool with broad applications in biomedical and environmental fields, underscoring the significance of this innovative sensor in advancing analytical methodologies. [ABSTRACT FROM AUTHOR]

The present study is devoted to investigating the mechanical characteristics of a novel natural rubber (NR)-based elastomer nanocomposite reinforced with carbon black and alumina nanoparticles acting as partial and primary reinforcements, respectively. Before conducting various mechanical tests on the specimens, the vulcanization properties of this elastomer nanocomposite was surveyed. It is demonstrated that adding the alumina nanoparticles to the NR-based elastomer matrix can significantly reduce the cure time and improve the quality of the vulcanizates. Then, the influence of alumina nanoparticles on the modulus, tensile strength, elongation at break, and energy absorption capacity of the elastomer nanocomposite were assessed, and the ideal nanoparticles' weight percentage was determined to be 10%. This is supported by calculating the Reinforcing Efficiency Parameter (REP), indicating that the elastomer nanocomposite with 10% alumina has the best reinforcing efficiency in tensile properties. Also, using the Split Hopkinson Pressure Bar (SHPB), it was found that the material is exceptionally strain-rate sensitive, and the specimens exhibited much higher values of stiffness and energy absorption under high strain-rate loading. It is inferred from the results that the elastomer nanocomposite reinforced with the optimal amount of alumina nanoparticles can be an excellent candidate for energy absorption applications under high strain-rate loadings. [ABSTRACT FROM AUTHOR]

In this study, an optimized model is proposed for predicting the effective conductivity of nanocomposites, which contains conductive spherical fillers above the percolation threshold. The influence of filler properties, interphase regions, filler concentrations, elemental cell sizes as well as contact area on the effective conductivity of nanocomposites was investigated and discussed in detail. The developed model is verified by using the experimental data reported in the literatures, and it is found that the prediction results are fitted well with the experimental results at different particle concentrations. In addition, high levels of filler conductivity, particle concentration, and elemental cell size led to a good conductivity. The maximum conductivity of nanocomposite with σeff = 1,500,000 S/m, Vf = 0.07, r = 10−4 nm, and D = 1250 nm is obtained at Ri = 40 nm and d = 10 nm. Furthermore, the conductivity of nanocomposite is not sensitive to interphase thickness, when d is larger than 25 nm. [ABSTRACT FROM AUTHOR]

Hybrid nanocomposites of high‐density polyethylene have been prepared via the melt‐mixing method in the presence of different amounts of graphene nanoplatelets (GNPs) and conductive carbon black (CB). The electrical conductivity, positive temperature coefficient (PTC), and the correlation between crystallinity and electrical conductivity of hybrid nanocomposites are investigated to study the effect of crystallinity on electrical conductivity. The samples are characterized using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X‐ray diffraction (XRD), and electrical resistivity. SEM micrographs reveal good distribution of CB and GNPs in nanocomposites. According to DSC and XRD results, the crystallinity of samples decreases by the addition of CB and GNP. The electrical conductivity of all the samples increases, whereas in the sample 16% of CB and 1% of GNP electrical conductivity decrease due to GNP acting as a heterogeneous nucleating agent and the numerous incomplete and small crystals formation. The highest electrical conductivity (1.46×10−4 S cm−1) is obtained in the sample high‐density polyethylene (HDPE)/CB18/GNP1, which shows high increment in the PTC curve in the range of 105−120 °C. Also, repeatability and reversibility of PTC in this sample show good potential for use in different applications such as thermistors, temperature sensors, and self‐regulating heaters. [ABSTRACT FROM AUTHOR]

TiC/Al–Cu nanocomposites were fabricated in Al–Ti–C powder systems using carbon black, a mixture of C and carbon nanotubes (C + CNTs), and CNTs via an in-situ method involving combustion synthesis and hot pressing. As the carbon source changed from pure carbon black to the C + CNT mixture and pure CNTs, the size of the TiC nanoparticles decreased gradually. The nanocomposites synthesized based on the C + CNT mixture exhibited the most uniform dispersion of TiC nanoparticles. The 30 vol% TiC/Al–Cu nanocomposite prepared from the C + CNT mixture had the best comprehensive mechanical properties (yield strength (411 MPa), compressive strength (712 MPa), fracture strain (17.2%), hardness (206.8 HV), and wear resistance under the experimental conditions due to having the most uniformly dispersed TiC nanoparticles. The wear mechanism was a combination of plastic deformation, abrasion, and adhesion. This method may be a low-cost and convenient means to control the sizes of in-situ TiC nanoparticles and prepare high-performance TiC/Al–Cu nanocomposites. [ABSTRACT FROM AUTHOR]

In the present work, Zeolite 13X and carbon black nanoparticles (CBNPs) reinforced polyvinylidene fluoride (PVDF) nanocomposites were obtained by a simple solvent casting technique. The structural, morphological and thermal properties of PVDF/Zeolite 13X/CBNPs nanocomposites with various loadings of Zeolite 13X and CBNPs were investigated using Fourier‐transform infrared spectroscopy, X‐ray diffraction, Scanning electron microscopy and thermo‐gravimetric analysis. The dielectric studies were carried out in the 50 Hz–10 MHz frequency range at room temperature. The electromagnetic interference (EMI) shielding effectiveness (SE) of PVDF/Zeolite 13X/CBNPs nanocomposite was investigated in the 8–18 GHz frequency region (X‐band and Ku‐band). The maximum EMI SE of approximately −11.1 dB (8–12 GHz) and −11.5 dB (12–18 GHz) was observed for PVDF/CBNPs nanocomposites with 10 wt% loading of CBNPs. These findings emphasize the application of PVDF/Zeolite 13X/CBNPs nanocomposites as a potential EMI shielding material. [ABSTRACT FROM AUTHOR]

3D printing plays an important role in Industry 4.0 and has versatility to use different materials, including thermoplastic polymers. Polylactic acid (PLA), a bio‐based biodegradable polymer, is used as a potential replacement for petroleum‐based polymers in several applications, and is one of the most popular polymers used in 3D printing. Inorganic/organic nanoparticles can be incorporated in polymers to improve various properties such as thermal, mechanical, and tribological. This work investigates the effect of adding carbon black (CB) and alumina (ALM) nanofillers on the thermal, mechanical, and tribological properties of 3D printed PLA nanocomposites for tribological applications. Both nanofillers promoted progressive enhancement of thermal stability according to TGA. The improvement in the interaction between nanofillers and PLA matrix is revealed by an increase in viscosity of the nanocomposites. The nanocomposites containing 25%wt ALM and 75wt% CB presented better mechanical and wear properties, suggesting synergism between nanofillers and that CB may act as a compatibilizer between PLA and ALM. These results enable selecting the most suitable composition of nanofillers to be added to PLA to create filaments with better tribological properties. [ABSTRACT FROM AUTHOR]

As an energy storage device, Zn–air battery has great market prospects due to its relatively high theoretical energy density, low cost, safe and reliable performances. Since the cathodic oxygen reduction reaction (ORR) is a sluggish kinetic process, efficient electrocatalysts are essential to facilitate the ORR. Herein, we report the one-step synthesis of non-precious metals loaded C–N tubular nanocomposites via the pyrolysis of the mixture composed of dicyandiamide (DCD), Co/Ni acetates, ethylenediamine, and different organic carbon sources like soluble starch(st), β-cyclodextrin(cyc) and carbon black(cb). The prepared nanocomposites present a hollow tubular structure, and the Co/Ni nanoparticles are uniformly distributed on the CN nanotubes. In the prepared catalysts, Co3Ni2/CN(st) exhibits excellent ORR electroactivity close to the Pt/C catalyst in the alkaline medium. An alkaline Zn–air battery is assembled by using the Co3Ni2/CN(st) as the cathodic electrocatalyst. The open-circuit voltage reaches 1.51 V in 6 mol L−1 KOH electrolyte and the maximum power density reaches 331 mW cm−2. At different discharging current densities, the Co3Ni2/CN(st) battery exhibits stable and higher voltage plateaus than the Pt/C battery. The battery can discharge continuously for up to 80 and 51 h, corresponding to the constant discharge current density of 50 and 100 mA cm−2, respectively. The results show that the Co3Ni2/C–N(st) catalyst has potential application prospects as an excellent cathodic material for alkaline Zn–air batteries. CoNi loaded C–N tubular nanocomposites with well-defined hollow tubular structure, synthesized by one-step pyrolyzing the mixture of cobalt//nickel salts, dicyandiamide (DCD) and different carbon sources including soluble starch(st), β-cyclodextrin(cyc) and carbon black(cb), present superior performance as the cathodic catalysts of alkaline Zn–air batteries. [ABSTRACT FROM AUTHOR]

Nanotechnology has been explored recently as a means of enhancing the properties of conventional elastomers for engineering applications. In the current study, the effect of nanofillers on air impermeability properties of Brominated isobutylene‐isoprene rubber (BIIR)/Epoxidized natural rubber (ENR) blend has analyzed for automotive applications. The ENR chosen is ENR 25 and ENR 50 (25 and 50% epoxidation) and prepared the blends in a ratio of 75:25 (BIIR:ENR), and from both blend based composites, a part of carbon black replaced with graphene nanoplatelets (GNP). The physical and thermal properties were compared for both binary blend nanocomposites to study the level of exfoliation and reinforcement behavior of GNP. Morphology studies were employed to reveal the level of interaction between GNP and carbon black in both blends. The influence of epoxidation in the formation of nanostructures in both blends have been evaluated, and the effect of nanostructures on air permeability properties was studied. The air impermeability of BIIR‐ENR 50 nanocomposites were improved with increasing platelet concentration, a 30% improvement in air permeability is obtained for BIIR‐ENR 50 composites over BIIR ‐ENR 25. [ABSTRACT FROM AUTHOR]

Hybrid rubber nanocomposite blends based on (80/20) XNBR/EPDM containing 5 phr Cloisite 10A, 15A 20A, 25A, 93A, 30B, carbon black and silica nanofiller and two types of EPDM-g-MA and ENR 50 containing 5 phr was prepared by a two roll mill. A rheometer test was used to study the curing of the blends, the tensile test was used to study the mechanical strength of the nanocomposite and XRD, FESEM and TEM tests were used to evaluate and observe the morphology of the nanocomposite blends prepared. The results of the rheometer test show that the Cloisite 30B nanofiller, in addition to increasing the torque and optimum cure time, decreased compared to other nanofillers. The results of the XRD test showed that the ENR50 compatibilizer with the Cloisite 30B nanofiller compared to other nanofillers, compared to the EPDM-g-MA compatibilizer, significantly increased the openness of the layers by 2.21 nm. The results of FESEM and TEM confirmed the better distribution of Cloisite 30B nanoparticles in the XNBR/EPDM sample containing ENR 50 compatibilizer. Also, XRD evidence showed that the opening of the nanofiller layers of Cloisite 30B was higher the other nanofillers. This result is consistent with microscopic observations. In addition, all nanoparticles are located in the XNBR phase. The results of the tensile test showed that the modulus and tensile strength of nanocomposite containing Cloisite 30B nanofiller and ENR 50 compatibilizer with other nanocomposites increased. [ABSTRACT FROM AUTHOR]

Hydrogel nanocomposites have been enthusiastically researched as promising candidates with cost-effectiveness and sustainability for solar steam generation and flexible electronics. Based on conductivity derived from salt ions and superior photo-vapor conversion of photothermal nanoparticles, hydrogel nanocomposites hold great potentials for ionotronics and desalination. Here, we report a mechanically robust and multifunctional gel-nacre nanocomposite based on carbon black (CB) nanoparticles strategically embedded in gel-nacre matrix, a physical crosslinked hydrogel reinforced via freeze–thaw and salting out with microphase separation structures. The CB nanoparticles play double roles of acting as nano-crosslinks and providing photothermal conversion capability, coupling gel-nacre matrix with shrinking tendency in saline, contributing to synergistical reinforcement of mechanical performances under saline conditions. The consequent CB@gel-nacre nanocomposite achieves comprehensive mechanical advantages (large strength, high toughness, ductility, and rapid self-recoverability), excellent electrical properties (good conductivity, high sensitivity, fast strain response) as well as photothermal conversion capability. Such versatile gel-nacre nanocomposite provides new opportunities for flexible devices in various scenarios such as ionotronics and desalination. [ABSTRACT FROM AUTHOR]

This paper presents the design, fabrication, and electromagnetic testing of a frequency selective surface (FSS)-based novel hybrid nanocomposite absorber for enhanced electromagnetic absorption. The proposed hybrid absorber consists of an FSS pattern printed over a dielectric substrate backed by aluminum foil, which is integrated together with a customized dielectric nanocomposite sheet. The dielectric sheet comprises the conducting carbon black (CB) nanopowders embedded into the epoxy matrix. The fabricated nanocomposite sheet is first characterized for the effective complex permittivity using the free-space measurement technique, and the measured electromagnetic properties are then used for the design of a hybrid absorber. The proposed hybrid absorber having overall thickness of 2.6 mm shows enhanced −10-dB absorption bandwidth of 3.5 GHz, which is much higher than that of the FSS and CB nanocomposite samples measured individually. The proposed work provides an effective way to combine the absorption properties of FSS with that of a customized dielectric absorber sheet in order to design an efficient hybrid absorber having reduced thickness with enhanced absorption bandwidth for stealth technology and various strategic applications. [ABSTRACT FROM AUTHOR]

Water barrier properties and tribological performance (hardness and wear behavior) of new hybrid nanocomposites under dry and wet conditions were investigated. The new fabricated hybrid nanocomposite laminates consist of epoxy reinforced with woven and nonwoven tissue glass fibers and two different types of nanoparticles, silica (SiO2) and carbon black nanoparticles (C). These nanoparticles were incorporated into epoxy resin as a single nanoparticle (either SiO2 or C) or combining SiO2 and C nanoparticles simultaneously with different weight fractions. The results showed that addition of carbon nanoparticles with 0.5 and 1 wt% resulted in maximum reduction in water uptake by 28.55% and 21.66%, respectively, as compared with neat glass fiber reinforced epoxy composites. Addition of all studied types and contents of nanoparticles improves hardness in dry and wet conditions over unfilled fiber composites. Under dry conditions, maximum reduction of 47.26% in weight loss was obtained with specimens containing 1 wt% carbon nanoparticles; however, in wet conditions, weight loss was reduced by 17.525% for specimens containing 0.5 wt% carbon nanoparticles as compared with unfilled fiber composites. Diffusion coefficients for different types of the hybrid nanocomposites were computed using Fickian and Langmuir models of diffusion. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Different DC electrical conductivity models have been proposed to predict the properties of composite materials. Among these, the Mamunya model gives a good agreement with experimental data for different carbon black nanocomposites below the threshold concentration. In this paper, we extend the study using the Scarisbrick model. However, the percolation phenomenon is not observed and a modified model which takes into account some parameters, such as the aspect ratio and surface area to volume ratio of fillers, is used to accurately justify the conductive network formation. The modified Scarisbrick model shows clearly the percolation phenomenon and gives satisfactory results for the series samples which present high percolation threshold. [ABSTRACT FROM AUTHOR]

The aim of this work was to obtain a suitable dispersion of carbon black (CB) nanoparticles in a polymer matrix using sodium dodecyl sulfate (SDS). The effect of SDS surfactant on dispersion of CB nanoparticles in solvent and epoxy resin and also the corrosion behavior of CB coatings were investigated by means of scanning and transmission electron microscopies, Zeta potential, dynamic light scattering and thermogravimetric analyser. The effect of CB nanoparticles dispersion on corrosion properties of nanocomposites was investigated by electrochemical impedance spectroscopy. The results showed improved corrosion resistance of the modified CB/epoxy coatings. [ABSTRACT FROM AUTHOR]

ABSTRACT This study evaluated physical properties of the nanocomposites reinforced by used coffee grounds. Coffee grounds were ball-milled and filtered in an effort to secure nanoparticles for the fabrication of polyvinyl alcohol (PVA)/coffee nanocomposites. We analyzed the particle size distribution of coffee particles and investigated mechanical and optical properties of the prepared nanocomposites. Carbon black (CB)-filled nanocomposites were also prepared to understand the physical behavior of the nanocomposites reinforced with coffee grounds and to explore the possibility of replacing CBs with nanosized coffee grounds used as a composite filler. It was found that the tensile strength and Young's modulus of PVA/coffee grounds nanocomposites were significantly enhanced compared with those of the PVA/CB nanocomposites. In addition, morphological observation for the nanocomposites was carried out using scanning electron microscopy (SEM). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42043. [ABSTRACT FROM AUTHOR]

Abstract: Polypropylene/carbon black (PP/CB) nanocomposites were prepared by melt compounding to investigate the effect of nanofiller loadings on the thermal and flammability properties of PP. The obtained nanocomposites displayed not only dramatically enhanced thermal stability both under nitrogen and in air, but also improved flame retardancy to some extent. Moreover, the higher the loading level of CB, the better was the improved effect. This enhanced mechanism was attributed mainly to trapping of peroxy radicals by CB nanoparticles at elevated temperature to form a gelled-ball crosslinked network, which act as a barrier to both heat and mass transfer. The thermal-oxidation cross-linking reaction was supported by the results of rheological properties, gel measurements and FTIR analysis. [Copyright &y& Elsevier]

Carbon black/ZnO nanocomposites have been successfully synthesized via a simple aqueous chemical growth method. The preparation of the carbon black/ZnO nanocomposites by adding an appropriate weight of carbon black to the ZnO growth process can be favorable to improve photocatalytic degradation of methyl blue under irradiation of ultraviolet light. Compare with commercial TiO 2 and ZnO nanopowders, carbon black/ZnO nanocomposites can enhance the specific surface area, the light-harvesting ability, and the charge carrier separation for achieving highly efficient photocatalysts under irradiation of both ultraviolet and visible light. The carbon black/ZnO nanocomposites exhibited a low cost and sample approach, high reusability, and high visible-light-induced photocatalytic activity. Image 1 • CB/ZnO nanocomposites can synthesize by a facile aqueous chemical growth method. • CB/ZnO nanocomposites exhibit high photocatalytic efficiency and reusability. • CB/ZnO nanocomposites exhibit higher photodegradation than ZnO and TiO 2 nanopowders. • Carbon black (CB) play a critical role to enhance the photocatalytic efficiency. [ABSTRACT FROM AUTHOR]

In this work, SnO2 and carbon black (CB) nanoparticles (NPs) were used to improve the physical and mechanical properties of polycarbonate films (PC) for industrial applications. Raman spectroscopy proved the successful inclusion of the fillers within the polymeric-based nanocomposites, with a suitable dispersion without changes in the structure and morphology of PC as denoted by scanning electron microscopy (SEM) and X-ray diffraction (XRD). After doping of the PC-based nanocomposites with CB, SnO2 and CB/SnO2 NPs, both the polymer hardness and the elastic modulus of the composites were observed to increase, with the highest value achieved for PC/CB-doped ones. Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DTG) indicated changes in the thermal properties of the polymer composites upon NP doping. Finally, molecular dynamics simulations were used to gain a better understanding about the interactions of PC and NPs in the nanocomposites. Simulation data obtained were in good agreement with experimental ones, which indicates that simulations can be an efficient toll in order to perform a preliminary high-throughput screening of diverse physico-chemical properties of polymeric-based nanocomposites bearing NP fillers before experimental development. [ABSTRACT FROM AUTHOR]