Search

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]

Carbon-based conductive polymer composites have attracted wide attention as candidates for high-performance flexible electric heaters. Herein, a poly(m-phenylene isophthalamide) (PMIA)/carbon black (CB) composite is proposed as electric heating films that can successfully realize stable and safe operation at high temperatures of > 200°C under a safe voltage as low as 20 V. The conductive filler content has a significant effect on the microstructure and electrical properties of the PMIA/CB composites. An optimized CB content of 20 wt.% in the PMIA polymer matrix not only guarantees uniform spatial dispersion, but also provides sufficient and stable conductive networks. As a result, the PMIA/CB composites present high heating temperature, rapid heating ability, good heating uniformity, and excellent heating reliability. Meanwhile, taking advantage of the high thermal stability, superior mechanical strength, and excellent flame retardancy of the PMIA polymer matrix, the PMIA/CB composites exhibit superior thermal endurance and self-extinguishing capabilities, leading to significantly enhanced operating safety. This study will open new avenues for the development of high-performance electrothermal composite films for medium- to high-temperature applications. [ABSTRACT FROM AUTHOR]

Pt2Ca nanoparticles with a mean size diameter of 6 nm can be prepared by heating K2PtCl6, CaH2, carbon black and KCl at 400–500 °C. A mechanism study suggests that the formation of the Pt2Ca phase at moderate temperature is enabled by the fast ion transport via the vacancies in the KCl–CaH2 solid solution. The Pt2Ca nanoparticles exhibit high performance for the oxygen reduction reaction in acid due to optimal adsorption energy of the oxygen intermediate. [ABSTRACT FROM AUTHOR]

Owing to the widespread use and improper emissions of carbon black nanoparticles (CBNPs), the adverse effects of CBNPs on human health have attracted much attention. In toxicological research, carbon black is frequently utilized as a negative control because of its low toxicity and poor solubility. However, recent studies have indicated that inhalation exposure to CBNPs could be a risk factor for severe and prolonged pulmonary inflammation and fibrosis. At present, the pathogenesis of pulmonary fibrosis induced by CBNPs is still not fully elucidated, but it is known that with small particle size and large surface area, CBNPs are more easily ingested by cells, leading to organelle damage and abnormal interactions between organelles. Damaged organelle and abnormal organelles interactions lead to cell structure and function disorders, which is one of the important factors in the development and occurrence of various diseases, including pulmonary fibrosis. This review offers a comprehensive analysis of organelle structure, function, and interaction mechanisms, while also summarizing the research advancements in organelles and organelle interactions in CBNPs-induced pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Currently, the primary focus for scientific authorities and regulatory departments revolves around water pollution. In this regard, photocatalysis has emerged as a highly effective, affordable, and goal‐oriented approach. Thus, recognizing the urgency of this issue, we focused our efforts towards developing a novel ternary photocatalytic structure based on mesoporous SrSnO3, combined with polypyrrole‐doped carbon black (PPC) and platinum nanoparticles (Pt NPs). Pt NPs, PPC and SrSnO3‐based nanocomposite photocatalyst was developed through a very simple chemical method followed by ultrasonication and photoreduction techniques. XRD analysis confirmed orthorhombic phase of SrSnO3, while the formation of the ternary nanocomposite among Pt NPs, PPC and SrSnO3 has been confirmed by X‐ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared (FTIR) spectroscopy. Transmission electron microscopy (TEM) revealed the presence of Pt NPs (5–15 nm), beads/dense cocoon like structures of PPC along with rod, spherical and needle shape nanostructures of SrSnO3 in newly created ternary photocatalyst. Diffuse reflectance spectroscopy (DRS) showed lowering of band gap energy in case of Pt@PPC/SrSnO3. Newly developed Pt@PPC/SrSnO3 nanocomposite worked efficiently when employed on colorless insecticide imidacloprid (IMD) and on colored methylene blue (MB) dye under UV‐light. Pt@PPC/SrSnO3 photocatalyst exhibited excellent performance with 96.03 % removal of pollutant IMD in only 20 min, almost 296 % more efficient than bare SrSnO3. Furthermore, the Pt@PPC/SrSnO3 ternary photocatalyst showed rapid removal of MB with almost total elimination of dye molecule in just 16 min. [ABSTRACT FROM AUTHOR]

Methodologies across the dispersion preparation, characterization, and cellular dosimetry of hydrophilic nanoparticles (NPs) have been developed and used extensively in the field of nanotoxicology. However, hydrophobic NPs pose a challenge for dispersion in aqueous culture media using conventional methods that include sonication followed by mixing in the culture medium of interest and cellular dosimetry. In this study, a robust methodology for the preparation of stable dispersions of hydrophobic NPs for cellular studies is developed by introducing continuous energy over time via stirring in the culture medium followed by dispersion characterization and cellular dosimetry. The stirring energy and the presence of proteins in the culture medium result in the formation of a protein corona around the NPs, stabilizing their dispersion, which can be used for in vitro cellular studies. The identification of the optimal stirring time is crucial for achieving dispersion and stability. This is assessed through a comprehensive stability testing protocol employing dynamic light scattering to evaluate the particle size distribution stability and polydispersity. Additionally, the effective density of the NPs is obtained for the stable NP dispersions using the volumetric centrifugation method, while cellular dosimetry calculations are done using available cellular computational modeling, mirroring approaches used for hydrophilic NPs. The robustness of the proposed dispersion approach is showcased using a highly hydrophobic NP model (black carbon NPs) and two culture media, RPMI medium and SABM, that are widely used in cellular studies. The proposed approach for the dispersion of hydrophobic NPs results in stable dispersions in both culture media used here. The NP effective density of 1.03–1.07 g/cm3 measured here for black carbon NPs is close to the culture media density, resulting in slow deposition on the cells over time. So, the present methodology for dispersion and dosimetry of hydrophobic NPs is essential for the design of dose–response studies and overcoming the challenges imposed by slow particle deposition. [ABSTRACT FROM AUTHOR]

Hansen Solubility Parameters (HSP), viewed in the context of similarity whenever dispersion is focused, offer valuable insights into the surface characteristics of nanoparticles. However, existing methods for determining HSP via the sedimentation of nanoparticles require multiple probe liquids, resulting in time‐consuming, costly experiments with potential health risks. To address this, we developed a two‐step strategy that enables a systematic selection of liquids. The key element of the approach is to first identify the rough location of the Hansen sphere in the three‐dimensional Hansen space using a well‐chosen set of probe liquids of different polarities and chemical structures. Then, depending on the outcome of the first step, a particular choice of liquids is made for the final HSP determination. Taken together, the introduced procedure reduces the amount of required liquids for experiments from currently more than ten to a maximum of seven chosen based on a well‐defined, coherent methodology. Validation was performed on carbon black, non‐pigmentary nano‐scale titania, silicon/carbon composites, and lanthanum cobaltite particles, i. e. relevant materials that are commonly utilized in fuel cells, batteries, cyclohexene oxidation, catalytic combustion, photocatalysis, and heterogeneous Fenton reactions. The study showcases the potential to save time, costs, and efficiently determine HSP values in a comparable manner. [ABSTRACT FROM AUTHOR]

Carbon nanofiber (CNF) films or mats have great conductivity and thermal stability and are widely used in different technological processes. Among all the fabrication methods, electrospinning is a simple yet effective technique for preparing CNF mats, but the electrospun CNF mats are often brittle. Here, we report a feasible protocol by which to control the alignment of carbon black nanoparticles (CB NPs) within CNF to enhance the flexibility. The CB NPs (~45 nm) are treated with non-ionic surfactant Triton-X 100 (TX) prior to being blended with a solution containing poly(vinyl butyral) and polyacrylonitrile, followed by electrospinning and then carbonization. The optimized CB-TX@CNF mat has a boosted elongation from 2.25% of pure CNF to 2.49%. On the contrary, the untreated CB loaded in CNF displayed a lower elongation of 1.85% because of the aggregated CB spots created weak joints. The controlled and uniform dispersion of CB NPs helped to scatter the applied bending force in the softness test. This feasible protocol paves the way for using these facile surface-treated CB NPs as a commercial reinforcement for producing flexible CNF films. [ABSTRACT FROM AUTHOR]

The present work describes the synthesis of an electroactive nanocomposite consisting of carbon black (CB) and polyaniline (PANI) obtained by in situ oxidative polymerization. Monomer P1 was used as a polyaniline precursor. P1 has surfactant properties that allow obtaining core–shell structures dispersed in an aqueous medium. The nanocomposite, together with silver nanoparticles (AgNPs) as an electrocatalytic element, was used to modify the surface of a glassy carbon electrode (GCE) for glucose detection. Electroactive areas were calculated using the Randles–Sevick equation. The results showed that the CB-PANI.1-1/AgNP nanocomposite exhibited a larger electroactive surface area (0.3451 cm2) compared to AgNP alone (0.0973 cm2) or the CB-PANI.1-1 composite (0.2989 cm2). Characterization of CB-PANI.1-1/AgNP, by cyclic voltammetry in the presence of glucose, showed a new oxidation peak with a maximum current close to 0.7 V due to the oxidation of glucose to gluconolactone. The amperometry test at 0.7 V showed a linear response with R2 of 0.999 as a function of the analyte concentration. The glucose sensor presented a linear detection range of 1 to 10 mM, a sensitivity of 41 µA mM−1 cm−2, and a limit of detection (LOD) of 520 µM. [ABSTRACT FROM AUTHOR]

Case bonded solid rocket motors hold significant importance in both the defense and aerospace industries which typically consist of an insulating layer, a solid propellant, and a liner layer serving as an adhesive between the insulator and solid propellant. In this investigation, the aim was to assess the critical mechanical properties of five different HTPB based liner formulations under ambient conditions, as well as at elevated and reduced temperatures. The liner formulations incorporated micro carbon black, nano carbon black, nano silica, and nano titania as fillers. A comprehensive characterization study encompassing mechanical and thermal properties was conducted to evaluate the performance of these potential rocket motor liners. Mobility reduction of polymer chains and bond strengthening at lower temperatures led to the enhancement in mechanical properties of all filled and unfilled liners with decline in temperature. All mechanical properties of filled liner formulations increased significantly compared to unfilled formulation at all temperatures. Enhancements in mechanical properties were more pronounced with carbon blacks as fillers. Thermal analyses of each formulation revealed that there were improvements in the thermal properties of filled liners compared to unfilled one. [ABSTRACT FROM AUTHOR]

• Waste PET bottles converted to carbon black for supercapacitors via 450 °C pyrolysis. • Sodium acetate WIS electrolyte gave highest potential window, capacitance at 2.4 V. • Supercapacitors achieved 233 F/g capacitance and 186.6 Wh/kg energy density. • CB showed 89.2 % crystallinity, 60 nm particles, and layered structure. • Demonstrates sustainable method to recycle PET waste into valuable energy materials. This study explores the conversion of polyethylene terephthalate (PET) waste into carbon black for its use in supercapacitors, offering a sustainable solution to waste management and energy storage needs. PET bottles were pyrolysed in an inert environment to produce carbon black. This plastic waste derived carbon was then characterised and used for electrode fabrication to explore its potential in supercapacitor applications. The supercapacitive properties of these electrodes were evaluated using cyclic voltammetry and charge–discharge techniques in various "Water-in-salt" electrolytes (WIS). WIS are the electrolytes in which the concentration of water is less than the concentration of salts by weight and volume. electrolytes. Sodium acetate (CH 3 COONa) exhibited the highest potential window and specific capacitance among the tested electrolytes. The derived carbon black demonstrated promising electrochemical performance, with a specific capacitance of 233 F/g and an energy density of 186.6 Wh/kg. These findings underscore the potential of carbon black derived from waste PET bottles as an effective material for supercapacitors, contributing to sustainable energy storage solutions and waste reduction. [ABSTRACT FROM AUTHOR]

• Pt&M/NC (M = Fe, Co) catalysts with an ultralow Pt loading (<3 wt%) are prepared. • In Pt&M/NC (M = Fe, Co), Pt is in the individual nanoparticles with the size < 2 nm. • M is conducive to create the spatial confinement effect to anchor Pt nanoparticles. • Synergistic effect of Pt, M and NC cause the good catalytic performance of Pt&M/NC. • This work provides a new method to reduce Pt use for ORR catalysts. In this work, we have prepared Pt and M nanoparticles on nitrogen-doped carbon catalysts (Pt&M/NC, M = Fe, Co) with an ultralow Pt loading (<3 wt%) from room reduction of Pt and 3d transition metals by sodium borohydride on NC, where NC is firstly from pyrolysis of carbon black together with melamine. In Pt&M/NC (M = Fe, Co), Pt and 3d transition metals are in the individual nanoparticles with the size < 2 nm, where M is conducive to create the spatial confinement effect to anchor Pt nanoparticles. Meanwhile, Pt&M/NC (M = Fe, Co) has more internal defects than those of Pt/NC and M/NC. Owing to the synergistic effect of Pt and M together with NC, electrochemical results show that Pt&Co/NC has the ORR peak potential and half wave potential of 0.863 and 0.840 V vs. RHE, respectively, where they are 0.848 and 0.827 V vs. RHE for Pt&Fe/NC, more positive than that of Pt/NC. The average electron transfer number of Pt&M/NC (M = Fe, Co) is more than 3.8, close to the four-electron transfer way. This work provides a new method to reduce Pt use for ORR catalysts. [ABSTRACT FROM AUTHOR]

• OER catalyst NiCoO x @CB was prepared successful through a spray-drying method. • The method is simple, environmentally friendly and easily scaled up. • NiCoO x particles exhibited average size <8 nm, offering numerous active site. • Wrapped structure could prevent active component from agglomerating during OER. • NiCoO x nanoparticles exist as an alloy oxide, promoting interatomic synergies. The search for the simple and convenient design method of a non-precious metal oxygen evolution catalyst is still an emerging strategy today. Usually, nano-alloy oxide can enhance the catalytic activity for large specific surface area and active site, which have been widely studied for the purpose of developing active electrocatalysts for water splitting, while, nanoparticles are fundamentally less stable and prone to substantial size growth in long-term operations. Therefore, a framework of hierarchical porous composite microsphere with NiCoO x nanoparticles wrapped by Carbon Black (NiCoO x @CB) was fabricated successfully through spray-drying in this paper. Benefitting from the porous nanostructure and 0 D nano-alloy oxide active site, a remarkable OER performance with a low overpotential for 241 mV at 10 mA·cm−2 in alkaline media was exhibited. And, from the support of wrapped structure, NiCoO x @CB showed a superior durability with 90 h for nanoparticles were prevented to reunion during the reaction. Also, the heterogeneous interfaces with strong charge transfers between CB and NiCoO x nanoparticles could enhance OER performance (NiCoO x showed 265 mV at 10 mA·cm−2). The proposed method in this paper work provide a facile route to construct the porous composite microsphere with excellent OER electrocatalytic activity based on non-noble metal oxide wrapped by CB. [ABSTRACT FROM AUTHOR]

• Re nanoparticles are prepared by a joint reduction method of carbon and hydrogen. • The as-obtained Re nanoparticles are only about 108.6 nm with a slight C and O. • The presence of carbon black can significantly reduce the particle size of products. • A further reduction of hydrogen can decrease the contents of C and O residues. Ultrafine powders are crucial for the preparation of high-performance Re-based materials via low-temperature sintering. In this work, a joint reduction method of carbon and hydrogen is proposed to prepare Re nanopowder for the first time. The former carbon black can significantly reduce the particle size of final products, and the latter hydrogen reduction can decrease the contents of carbon and oxygen residues. And the as-obtained rhenium nanopowder is only about 108.6 nm with a slight carbon (0.019 wt%) and oxygen (0.03 wt%). This method is straightforward, easy to implement, low-cost and conducive to the large-scale industrial production. [ABSTRACT FROM AUTHOR]

A new, facile, and template-free method to prepare high surface area microporous carbon nanocubes (CNCs) from a mixture of graphene oxide nanoribbons (NRs), graphene oxide, and carbon dots is reported. The nanoribbons, approximately 30 nm wide and with lengths ranging from a few tens of nanometres up to several micrometres, were obtained from the oxidation of Black Pearls 2000 carbon black in nitric acid solution. The non-purified nanoribbons further contained additional fragments of graphene oxide, and of graphene oxide quantum dots. Slow pyrolysis of the nanoribbon mixture with slow heating rates, e.g., 3 °C/min, yielded carbon nanocubes approximately 250 nm in size with surface areas greater than 900 m2/g. Heating rates of 50 °C/min led to carbons with ∼800 m2/g surface area but bulk morphology. Precipitating the nanoribbons in potassium hydroxide solution, followed by carbonization, yielded microporous nanoparticle aggregates that were 20 nm in size with surface areas greater than 2000 m2/g. The particles exhibited complex, quasi-spherical morphology. Pyrolysis of other products obtained from oxidation in HNO 3 of different grades of carbon black, specifically graphene oxide nanoparticles and quantum dots, yielded high surface area microporous carbons but with bulk morphology regardless of the processing conditions. Despite the lower surface area and pore volume of the CNCs in comparison to the nanospheres, the former contained ultramicropores that were highly accessible to CO 2 as a molecular probe and had excellent selectivity of CO 2 over N 2. Hence, CNC materials have promising properties for applications where particle surface-to-volume ratios, high internal surface areas, and abundant super and ultramicropores are desired. [Display omitted] [ABSTRACT FROM AUTHOR]

• Carbon nanoparticle aggregation and coalescence behavior. • Integration of coalescence dynamics into a CCA model. • Thermophoretic sampling is superior to filter sampling. • Experimental morphology and morphology by simulation agreed well. The coalescence behavior of carbon nanoparticle, such as soot and carbon black, has not been so much discussed. This study delves into the intricate behavior of nanoparticle aggregates, with a keen emphasis on the variations in their shape and size based on coalescence dynamics. The coalescence rate obtained from previous experimental results was implemented in an aggregate mean free path cluster–cluster aggregation model. The effect of coalescence on morphology was examined by classifying the aggregates obtained using the cluster–cluster aggregation model in terms of their complexity. We contrasted the results of cluster–cluster aggregation simulation with experimental aggregate shape analyzing electron microscopy images and experimental primary particle size distribution. When neglecting coalescence, proportion of branched-shape aggregates was higher, whereas accounting for coalescence resulted in predominantly ellipsoidal or spherical particles. Contrasting simulations with experimental data reveals that filter-sampling methods may overemphasize aggregate complexity. Contrarily, thermophoretic sampling provided a closer match to simulation predictions. A pivotal finding was that the coalescence model, when coupled with accurate experimental sampling techniques, aligns closely with the experimental observations. [ABSTRACT FROM AUTHOR]

Modifying stainless steel (SS) surfaces with biocompatible materials is a practical approach to making SS an efficient electrode material for microbial electrochemical systems (MESs). However, a simple, cost-effective method to modify large-size SS is still missing. Here, we proposed to use spray coating to modify SS mesh (SSM) with acetylene black (AB) nanoparticles to make SSM an efficient anode material for MESs. The SEM images and Raman spectrum confirmed that AB nanoparticles could be uniformly coated onto the surface of SSM. The AB nanoparticles dramatically increased the specific surface area and biocompatibility of SSM. Consequently, when tested as the anode in MESs, the AB-coated SSM exhibited excellent biofilm formation ability, while the bare SSM saw inferior biofilm formation potential. Moreover, the current density achieved on the AB-coated SSM (1.95 ± 0.1 mA/cm2) was orders of magnitudes higher than that achieved on the bare SSM (0.01 ± 0.01 mA/cm2). Compared to other surface modification methods for SS, spray coating is simple, cost-effective, and most importantly readily for large-size SS electrodes. Therefore, spray coating of carbon nanoparticles holds excellent potential for scaling up SS electrodes for MESs. [Display omitted] [ABSTRACT FROM AUTHOR]