Presence Of Carbon Nanoparticles Research Articles

Chinese ink-coated elastic PU/PET fibers as multifunctional flexible wearable sensors

Textiles as conductive substrates are widely used in sensing applications due to their good elasticity, high stretchability and recoverable deformation. Here, the mask rope (polyurethane/polyester blended fibers) was selected as flexible substrate to load of conductive Chinese ink using surface swelling technique in N, N-dimethylformamide. The presence of carbon nanoparticles in the ink imparts electrical conductivity to the elastic fiber while maintaining the mechanical properties and extensibility of the fiber. This simple and low-cost method allows excellent interfacial adhesion between the conductivity ink layer and the elastic fibers, and the carbon particles do not fall off even when the modified fiber was treated by sonication in water. The ink coated elastic fiber as strain sensor shows excellent stability and sensitive responsiveness after 500 stretch-release cycles. The response and recovery times during the sensitivity experiment of the flexible fiber sensor are 133.79 and 134.76 ms. The sensor exhibits physiological motion detection and quality monitoring capabilities, which can accurately monitor human movements such as walking, wrist movement, throat swallowing and articulation. The sensor also has a good Joule heating effect, and the temperature of the conductive fiber can increase 88.9°C in the 60 s under 15 V voltage. This work develops a simple and efficient, low-cost, mass-producible flexible sensor with potential for physiological activity, temperature, and humidity detection.

Influence of Heat Treatment on Microstructure, Mechanical Properties, and Damping Behavior of 2024 Aluminum Matrix Composites Reinforced by Carbon Nanoparticles.

Nanocarbon 2024 aluminum composites with 0.5 vol. % and 1 vol. % of graphene nanoplatelets and 1 vol. % and 2 vol. % of activated nanocarbon were manufactured through induction casting. The effect of the reinforcements and heat treatment on the performance of the composites was examined. Analysis of the microstructure of the composites before heat treatment suggested the homogeneous dispersion of reinforcements and the absence of secondary carbide or oxide phases. The presence of carbon nanoparticles had a significant impact on the microstructural characteristics of the matrix. This behavior was further enhanced after the heat treatment. The mechanical and damping properties were evaluated with the uniaxial compression test, micro Vickers hardness test, and dynamic mechanical analysis. The yield strength and ultimate strength were improved up to 28% (1 vol. % of graphene nanoplatelets) and 45% (0.5 vol. % of graphene nanoplatelets), respectively, compared to the as-cast 2024 aluminum. Similarly, compared to the heat-treated 2024 aluminum, the composites increased up to 56% (0.5 vol. % of graphene nanoplatelets) and 57% (0.5 vol. % of graphene nanoplatelets) in yield strength and ultimate strength, respectively. Likewise, the hardness of the samples was up to 33% (1 vol. % of graphene nanoplatelets) higher than that of the as-cast 2024 aluminum, and up to 31% (2 vol. % of activated nanocarbon) with respect to the heat-treated 2024 aluminum. The damping properties of the nanocarbon-aluminum composites were determined at variable temperatures and strain amplitudes. The results indicate that damping properties improved for the composites without heat treatment. As a result, it is demonstrated that using small volume fractions of nanocarbon allotropes enhanced the mechanical properties for both with- and without-heat treatment with a limited loss of plastic deformation before failure for the 2024 aluminum matrix.

Carbon Nanoparticles Extracted from Date Palm Fronds for Fluorescence Bioimaging: In Vitro Study.

Numerous studies have been reported on single- and multicolored highly fluorescent carbon nanoparticles (FCNPs) originating from various sources and their potential applications in bioimaging. Herein, multicolored biocompatible carbon nanoparticles (CNPs) unsheathed from date palm fronds were studied. The extracted CNPs were characterized via several microscopic and spectroscopic techniques. The results revealed that the CNPs were crystalline graphitic and hydrophilic in nature with sizes ranging from 4 to 20 nm. The unsheathed CNPs showed exemplary photoluminescent (PL) properties. They also emitted bright blue colors when exposed to ultraviolet (UV) light. Furthermore, in vitro cellular uptake and cell viability in the presence of CNPs were also investigated. The cell viability of human colon cancer (HCT-116) and breast adenocarcinoma (MCF-7) cell lines with aqueous CNPs at different concentrations was assessed by a cell metabolic activity assay (MTT) for 24 and 48 h incubations. The results were combined to generate dose-response curves for the CNPs and evaluate the severity of their toxicity. The CNPs showed adequate fluorescence with high cell viability for in vitro cell imaging. Under the laser-scanning confocal microscope, the CNPs with HCT-116 and MCF-7 cell lines showed multicolor fluorescence emissions, including blue, green, and red colors when excited at 405, 458, and 561 nm, respectively. These results prove that unsheathed CNPs from date palm fronds can be used in diverse biomedical applications because of their low cytotoxicity, adequate fluorescence, eco-friendly nature, and cheap production.

Formation of Gold Nanoparticles in the Presence of Carbon Nanoparticles

Formation of Gold Nanoparticles in the Presence of Carbon Nanoparticles

Effect of pulmonary surfactant on the dispersion of carbon nanoparticles

Carbon nanoparticles (CNs) are widely used and there has been a great concern about their potential adverse effects on human health. CNs can directly interact with the pulmonary surfactant (PS) lining of alveoli, but the dispersion state of CNs at PS film has not yet been explored. Accumulating evidences indicated that the degree of dispersion of nanoparticles has a strong influence on their biological activities. This study investigated the effect of PS and its major components on the dispersion state of three representative CNs (fullerene C60, nano carbon powder, graphene oxide). The results demonstrated that suspended concentrations of all three CNs were lower in the presence of PS and its lipid component dipalmitoylphosphatidylcholine (DPPC) than in the presence of bovine serum album (BSA). Compared with PS and DPPC, BSA notably reduced the hydrodynamic diameters of CNs. In addition, the absolute zeta potentials of CNs in the presence of BSA was higher than those in the presence of PS or DPPC, and this result corresponds to the increase of surface oxygen contents of CNs, indicating that relatively high surface oxygen content is beneficial for the dispersion of CNs in alveolus. π-A isotherms demonstrated that the surface tension and phase behavior of PS were obviously altered in the presence of CNs. This study revealed the role of PS and different active components in the dispersion of CNs, which is helpful for deeply understanding CNs alveolar transport and the associated potential hazards to lung health. • Interaction of PS with carbon nanoparticles (CNs) leads to the aggregation of CNs. • Lipids and protein components of PS exert different effects on CNs dispersion. • Hydrodynamic diameter/zeta potential impact the dispersion of CNs with PS component. • Surface oxygen content of CNs governs the dispersion of CNs. • CNs exposure leads to the alternation of phase behavior of PS film.

RETRACTED ARTICLE: Genotoxicity and alteration of the Gene Regulatory Network expression during Paracentrotus lividus development in the presence of carbon nanoparticles

AbstractNanoparticles are a newly emerging class of pollutants with eco-toxicological impacts on marine ecosystems; they are characterized by nano-scale size which improves their physical, chemical and biological properties. To better understand the mechanisms of embryotoxicity of carbon-based nanoparticles, the genotoxicity and the perturbation of the Gene Regulatory Network (GRN) expression have been investigated during the development of the sea urchinParacentrotus lividusfrom fertilization to early pluteus stage. Increasing quantities of carbon nanoparticles (C-NPs), 0.5, 2.5 and 25 × 1013C-NPs/500 cm3of filtered seawater were administered during fertilization and the development was monitored up to the early pluteus stage (48 h). DNA damage and gene expression were assayed by Comet assay and Real-Time PCR, respectively. Taken together, our results indicate that embryo malformations taking place in the presence of C-NPs are due to altered regulation of the GNR and to a progressive accumulation of DNA single-strand breaks.

Structural and Biological Activity of Micro-Nanoparticles Produced from Highly Activated Carbonic Adsorbent

Over the recent years, carbon nanoparticles have gained relevance in the field of biomedical application to diminish the level of endo- / exogenous intoxication and oxidative stress products, which occur at different pathological states. However, it is very important that such carbon nanoparticles, specially developed for parenteral administration or per oral usage, possess a high adsorption potential and can remove hazard toxic substances of the hydrophilic, hydrophobic and amphiphilic nature usually accumulated in the blood due to the disease, and also be absolutely safe for normal living cells and tissues of organism. In this work, the stable monodisperse suspension containing very small-sized (1125.3 ±243.8 nm) and highly pure carbon particles with an excellent accepting ability were obtained. UV-spectra, fluorescence quenching constant, and binding association constant were provided by the information about conformational alterations in an albumin molecule in presence of carbon nanoparticles, about the dynamic type of quenching process and low binding affinity between carbon and protein. The later was confirmed by DSC method. In vitro cell culture experiments showed that carbon nanoparticles did not possess cytotoxic effect towards all testing the normal cell lines of different histogenesis, did not show genotoxic effects and were absolutely safe for experimental animals during and after their parenteral administration. These observations may provide more information about how to develop a safe preparation of carbon nanoparticles for different biomedical applications, in particular, as a mean for intracorporeal therapy of various heavy diseases accompanied by the increased endogenous intoxication and the level of oxidative stress.

Experimental studies of optoacoustic effect on the model of erythrocytes in the presence of carbon nanoparticles

Experimental model has been developed to study optoacoustic signal from model blood cells presented by polystyrene microspheres with nanoparticles. It was found out that nanoparticles due to their strong absorption of light significantly affect the coefficient of cellular optical absorption, while the thermophysical parameters, namely the coefficient of thermal expansion, compressibility and isobaric specific heat of cells remain unchanged, since nanoparticles occupy a small intracellular volume compared to the cell volume. Optoacoustic signals were obtained using model solutions at various concentrations of cells and nanoparticles using 1064 nm laser. The results of experimental measurements using LIMO 100–532/1064-U system based on Nd:YAG showed that the amplitude of the optoacoustic signal increased without increasing the temperature in the laser area.

Thermal and hydraulic performance of a heat exchanger working with carbon-water nanofluid

In the present paper, the heat transfer and fluid flow characteristics of a copper-made heat exchanger were experimentally studied. The configuration of the heat exchanger was a double pipe and carbon-water nanofluid was utilised as a heat-exchanging medium within the heat exchanger. Experiments were conducted at volume fractions 0.1–1% and Reynolds number 800–10500. Plausible effect of various parameters including the nanofluid flow rate, nanoparticles’ volumetric concentration and film temperature on the overall heat transfer coefficient (HTC) were investigated. Results showed that carbon/water nanofluid can offer a great potential for cooling applications. It was found that the flow rate of nanofluid; concentration and temperature of nanofluid can enhance the HTC. Interestingly, the presence of carbon nanoparticles within the base fluid resulted in the augmentation of pressure drop. This was because of the enhancement in friction factor parameter between layers of the base fluid and the augmentation in fluid viscosity, which is attributed to the presence of nano-carbons, which increased the pressure drop. Significant improvement in overall HTC was registered (44% enhancement) achieved at vol.% =1. The penalty of 14% was reported for the pressure drop at vol.% = 1, which offers a trade-off between the increase in the value of HTC and augmentation in the value of pressure drop. The maximum value for thermal hydraulic performance of the system was 42.2% at Reynolds number 10200 and vol.% = 1.

Joint Effect of Small Additives of Carbon Nanoparticles of Different Morphologies on the Mechanical Characteristics of Cross-Linked Polyurethanes under Static and Dynamic Loads

Influence of small additives of fullerene, graphene oxide, and their combinations in the ratio of 85 : 15 on the structure and mechanical properties of cross-linked polyurethanes under static and dynamic loads has been investigated. Nanocomposite structures have been studied by X-ray diffraction analysis and scanning electron microscopy. It is shown that the presence of carbon nanoparticles in the composite reduces its strength under both static and shock-wave loads. The synergistic effect of the mixture of carbon nanoparticles manifests itself as an increase in the elastic modulus by a factor of 1.25 in comparison with the initial polymer.

Synergetic effect of fullerene and graphene oxide nanoparticles on mechanical characteristics of cross-linked polyurethanes under static and dynamic loading

The effect of low concentration of fullerene, graphene oxide and their combinations at an 85/15 ratio as additives on structure and mechanical properties of cross-linked polyurethanes has been studied at static and dynamic loading. Structure of nanocomposites has been determined from X-ray analysis and scanning electron microscopy. It has been shown that the presence of carbon nanoparticles in a composite results in its lower strength under both static and shock-wave loads. The synergetic effect of carbon nanoparticles mixture is revealed to have 1.25 times higher Young's modulus as compared with native polymer.

Polymeric membranes based on cellulose acetate loaded with candle soot nanoparticles for water desalination

This study is concerned with modifying cellulose acetate (CA)/polyethylene glycol (PEG) membranes prepared via phase inversion technique in the presence of carbon nanoparticles; candle soot (CS) resulting from combusted candle. CS nanoparticles were analyzed via Fourier transform infrared spectroscopy and transmission electron microscopy. The developed membranes were characterized for their surface morphology, mechanical properties as well as thermal stability. CS nanoparticles contributed in improving the salt rejection % with a slight reduction in the water flux behavior. Employing the annealed cellulose acetate/polyethylene glycol membranes loaded with candle soot nanoparticles provides an adequate approach towards water desalination implementations.

Эффект совместного влияния малых добавок углеродных наночастиц различной морфлогии на механические характеристики сшитых полиуретанов при статических и динамических нагрузках

AbstractInfluence of small additives of fullerene, graphene oxide, and their combinations in the ratio of 85 : 15 on the structure and mechanical properties of cross-linked polyurethanes under static and dynamic loads has been investigated. Nanocomposite structures have been studied by X-ray diffraction analysis and scanning electron microscopy. It is shown that the presence of carbon nanoparticles in the composite reduces its strength under both static and shock-wave loads. The synergistic effect of the mixture of carbon nanoparticles manifests itself as an increase in the elastic modulus by a factor of 1.25 in comparison with the initial polymer.

An efficient fabrication of ZnO–carbon nanocomposites with enhanced photocatalytic activity and superior photostability

Synthesis of carbon nanoparticles (CNPs) and their composite with ZnO has proposed for the first time by combustion of camphor and chemical precipitation method. TEM image shows the surface of ZnO covered by tiny CNPs and acts as structure directing agent that transforms ZnO nanorods to uniform spherical ZnO. CNPs play a vital role to improve the photocatalytic activity and photostability of ZnO up to five runs due to impeding the photo-corrosion of ZnO. Enhance in the photocatalytic activity of ZnO–carbon nanocomposite could be attributed to the excellent dye adsorption capacity, direct photooxidation of dye and suppression of photoinduced electron–hole recombination. The presence of CNPs in nanocomposite served as the main role in accepting the photogenerated electrons due to electronic interaction between ZnO and CNPs. The cytotoxicity studies of meristematic root tip cells of Allium cepa reveals that photocatalytically degraded products were less toxic.

Effect of Morphological Changes due to Increasing Carbon Nanoparticles Content on the Quasi-Static Mechanical Response of Epoxy Resin.

Mechanical failure in epoxy polymer and composites leads them to commonly be referred to as inherently brittle due to the presence of polymerization-induced microcrack and microvoids, which are barriers to high-performance applications, e.g., in aerospace structures. Numerous studies have been carried out on epoxy’s strengthening and toughening via nanomaterial reinforcement, e.g., using rubber nanoparticles in the epoxy matrix of new composite aircraft. However, extremely cautious process and functionalization steps must be taken in order to achieve high-quality dispersion and bonding, the development of which is not keeping pace with large structures applications. In this article, we report our studies on the mechanical performance of an epoxy polymer reinforced with graphite carbon nanoparticles (CNPs), and the possible effects arising from a straightforward, rapid stir-mixing technique. The CNPs were embedded in a low viscosity epoxy resin, with the CNP weight percentage (wt %) being varied between 1% and 5%. Simplified stirring embedment was selected in the interests of industrial process facilitation, and functionalization was avoided to reduce the number of parameters involved in the study. Embedment conditions and timing were held constant for all wt %. The CNP filled epoxy resin was then injected into an aluminum mold and cured under vacuum conditions at 80 °C for 12 h. A series of test specimens were then extracted from the mold, and tested under uniaxial quasi-static tension, compression, and nanoindentation. Elementary mechanical properties including failure strain, hardness, strength, and modulus were measured. The mechanical performance was improved by the incorporation of 1 and 2 wt % of CNP but was degraded by 5 wt % CNP, mainly attributed to the morphological change, including re-agglomeration, with the increasing CNP wt %. This change strongly correlated with the mechanical response in the presence of CNP, and was the major governing mechanism leading to both mechanical improvement and degradation.

Tetsubo-like α-Fe2O3/C nanoarrays on carbon cloth as negative electrode for high-performance asymmetric supercapacitors

To explore novel negative electrode materials with high special capacitance for high-performance asymmetric supercapacitors, in this article, α-Fe2O3/C nanoarrays on carbon cloth with tetsubo-like structure was synthesized as a free-standing negative electrode for supercapacitor. The characterizations indicated that these α-Fe2O3/C nanoarrays are hollow structure and composed of α-Fe2O3 nanocrystals and carbon nanoparticles. In addition, there are plenty of mesopores existed between these α-Fe2O3 nanocrystals and carbon nanoparticles. Due to the hollow porous structure of α-Fe2O3/C nanoarrays and the presence of carbon nanoparticles not only in favor of accelerating the transport of electron and ion in α-Fe2O3/C electrode, but also increasing the active sites for energy storage, the as-synthesized α-Fe2O3/C electrode delivered much enhanced electrochemical performance including a high specific capacitance up to 430.8 mF cm−2 and 391.8 F g−1 at a current density of 1 mA cm−2, good rate capability with a capacitance retention of 73.2% of capacitance retention at 10 mA cm−2 and great cycling stability with only 8.2% capacitance loss after 4000 cycles at a scan rate of 200 mV s−1. By using α-Fe2O3/C as negative electrode and MnO2 as positive electrode, an asymmetric supercapacitor was assembled to examine the electrochemical performance of α-Fe2O3/C in-depth. Benefit from the unique design of the α-Fe2O3/C electrode, the asymmetric supercapacitor exhibited a high energy density of 0.64 mWh cm−3 at the power density of 14.8 mW cm−3 in 1 M Na2SO4 electrolyte and 0.56 mWh cm−3 at the power density of 16.8 mW cm−3 in Na2SO4/CMC gel electrolyte. These satisfactory results prompt the as-fabricated hollow porous α-Fe2O3/C to use as a promising negative electrode material for high-performance supercapacitors.

A novel synthesis method of hierarchical mesoporous MgO nanoflakes employing carbon nanoparticles as the hard templates for photocatalytic degradation

We describe a novel synthesis method for the preparation of bimodal mesoporous MgO nanoflakes and their application in photocatalytic activity for the degradation of methylene blue dye under UV light irradiation. For this purpose, Mg(OH)2/carbon nanocomposite was obtained through the precipitation of magnesium hydroxide in the presence of carbon nanoparticles. X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), and transition electron microscopy (TEM) micrographs have shown that this strategy could be successfully used to prepare bimodal mesoporous MgO nanoflakes with two different pore size distributions centered at 3 and 25nm and a high specific surface area of 216.9m2/g. Furthermore, the product was used as an adsorbent to remove methylene blue dye from aqueous media. The results confirmed that the photocatalytic activity of the synthesized mesoporous MgO was significantly improved due to the presence of such different pore sizes and high specific surface area resulting in higher adsorption, storage, and degradation of dye molecules.

Quantitative Aspects of the Interfacial Catalytic Oxidation of Dithiothreitol by Dissolved Oxygen in the Presence of Carbon Nanoparticles.

The catalytic nature of particulate matter is often advocated to explain its ability to generate reactive oxygen species, but quantitative data are lacking. We have performed molecular characterization of three different carbonaceous nanoparticles (NP) by 1. identifying and quantifying their surface functional groups based on probe gas-particle titration; 2. studying the kinetics of dissolved oxygen consumption in the presence of suspended NP's and dithiothreitol (DTT). We show that these NP's can reversibly change their oxidation state between oxidized and reduced functional groups present on the NP surface. By comparing the amount of O2 consumed and the number of strongly reducing sites on the NP, its average turnover ranged from 35 to 600 depending on the type of NP. The observed quadratic rate law for O2 disappearance points to a Langmuir-Hinshelwood surface-based reaction mechanism possibly involving semiquinone radical. In the proposed model, the strongly reducing surface site is assumed to be a polycyclic aromatic hydroquinone whose oxidation to the corresponding conjugated quinone is rate-limiting in the catalytic chain reaction. The presence and strength of the reducing surface functional groups are important for explaining the catalytic activity of NP in the presence of oxygen and a reducing agent like DTT.

Binding analysis of carbon nanoparticles to human immunoglobulin G: Elucidation of the cytotoxicity of CNPs and perturbation of immunoglobulin conformations

The chemical compositions, sizes and fluorescent properties of synthesized carbon nanoparticles (CNPs) were characterized. Escherichia coli (E. coli) cells were used as a model to study the cytotoxicity of CNPs, and the results of the cellular uptake of CNPs yielded excellent results: the CNPs demonstrated good biocompatibility and were non-toxic to the growth of the E. coli cells. Moreover, to assess the potential toxicity of CNPs to human health, the binding behavior of CNPs with human immunoglobulin G (HIgG) was examined by fluorescence quenching spectroscopy, synchronous fluorescence spectroscopy and circular dichroism spectroscopy under physiological conditions. The fluorescence quenching constants and parameters for the interaction at different temperatures had been calculated according to Scatchard. The thermodynamic parameters, such as enthalpy change (ΔH), entropy change (ΔS) and free energy change (ΔG), were calculated, and the results indicated strong static quenching and showed that van der Waals forces, hydrogen bonds and hydrophobic interactions were the predominant intermolecular forces stabilizing the CNP–HIgG complex. Synchronous fluorescence and circular dichroism spectra provided information regarding the conformational alteration of HIgG in the presence of CNPs. These findings help to characterize the interactions between CNPs and HIgG, which may clarify the potential risks and undesirable health effects of CNPs, as well as the related cellular trafficking and systemic translocation.

Simultaneous detection of pathogenic bacteria using an aptamer based biosensor and dual fluorescence resonance energy transfer from quantum dots to carbon nanoparticles

We report on a method for simultaneous detection of the pathogens Vibrio parahaemolyticus and Salmonella typhimurium. It is based on dual fluorescence resonance energy transfer (FRET) from green-emitting quantum-dots (gQDs) and red-emitting quantum-dots (rQDs) as donors, and on novel amorphous carbon nanoparticles (CNPs) that act as acceptor. The gQDs were modified with an aptamer (Apt 1) recognizing V. parahaemolyticus, and the rQDs with an aptamer (Apt 2) recognizing S. typhimurium. The fluorescence of both QDs is strongly quenched in the presence of CNPs. However, on addition of the target analytes, the QDs-aptamer-target complex is formed and quenching by CNPs is suppressed. The fluorescence of the QDs is linearly proportional to the concentration of the two pathogens in the range from 50 to 106 cfu·mL−1, with detection limits as low as 25 cfu·mL−1 for V. parahaemolyticus, and of 35 cfu·mL−1 for S. typhimurium. The assay was applied to real food samples, and the results were consistent with the results obtained with plate counting methods. We presume that this strategy can be extended to the detection of other pathogenic bacteria and biomolecules by simply substituting the aptamer.