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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]

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]

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]

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]

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]