Nanocarbon Additives Research Articles

Selection of second-generation crop for biodiesel extraction and testing its impact with nano additives on diesel engine performance and emissions

The scope of this study was twofold: to define the most suitable Egypt's biodiesel source, and to assess the impact of this biodiesel source with the addition of carbon nano additives on diesel engine performance and emissions. Environmental Key Performance Indicators were used as metrics to identify the appropriate biodiesel source with respect to several criteria including environmental, economic, ecological, and demographic situation. The most suitable Egypt's biodiesel source was identified from different sources including algae, Jatropha, coffee waste, rice straw, sugarcane, and switchgrass. Then, the production process of biodiesel from this renewable source by transesterification was carried out using chemical catalyst or biocatalyst. Following this, this source's impact with carbon nano additives on the performance and emissions of a 0.825-L single-cylinder diesel engine was further examined at engine loads varying between 0 and 4 kW and 1500 rpm constant engine speed. The carbon nano additives were added at a different mass fractions of 25, 50 and 100 ppm to Jatropha biodiesel and diesel blend (20 % jatropha biodiesel+ 80 % diesel) by volume. The results showed Jatropha as the most efficient biodiesel source among all the tested fuels to be produced in Egypt. Furthermore, the experimental engine test results revealed that Jatropha biodiesel without and with carbon nano additives consistently has a higher brake thermal efficiency and lower brake specific fuel consumption in comparison to that of diesel fuel. Likewise, Jatropha biodiesel without and with carbon nano additives enhanced the engine performance and consequently reduced the exhaust emissions including CO, CO2, HC, NOx, and smoke in comparison to that of diesel fuel.

Laser initiation of modified complex cobalt (III) perchlorate

AbstractThe article presents the results of quantum‐chemical calculations of an isolated molecule of pentaammine‐(5‐nitro‐2H‐tetrazolato‐N2)cobalt (III) perchlorate (complex 1, NCP) and the products of its possible primary decomposition stage. Using Quantum chemical calculations in the approximation of the density functional theory, it was shown that the decomposition of complex 1 probably starts with the destruction of the 5‐nitrotetrazole ligand and the elimination of the nitrogen molecule, but not with the elimination of the coordinated ammonia molecule from the inner sphere of the cobalt complex. The likelihood of this mechanism increases with the addition of highly conductive nanocarbon additives. The effect of the addition of multilayer graphene additives on the interaction of laser radiation with the above complex has been examined in detail, and two variants of mechanisms for this effect have been identified. A real model of a laser detonator based on the experimental data, has been created.

The influence of high-energy ball milling and nanoadditives on the kinetics of heterogeneous reaction in Ni-Al system

Kinetic studies were performed utilizing high-speed temperature scanner in the Ni-Al system including those with and without mechanical activation (MA) of different duration in a planetary ball mill, with and without using carbon nanoadditives (NA). The temperature profiles were taken and treated at different heating rates from 100 up to 2600 °C/min considering the influence of activation duration and the role of nanoadditive on the characteristic points of thermograms. Kissinger method allowed to evaluate activation energy (Ea) for non-activated, activated (1, 2, 3, 5 min), nanoadditive (1 wt.%) containing and nanoadditive (1 wt.%) containing mechanoactivated (1, 3, 5 min) mixtures. The beneficial influence of NA on the interaction between Ni and Al in the non-activated and moderately mechanoactivated mixtures was demonstrated. The influence of MA and NA on the microstructure features and phase formation sequence at various heating rates were revealed. For all the mixtures under study, T* characteristic temperatures (the temperature, where the maximum exothermic effect was observed) were found to increase with increasing heating rates. It was unravelled that mechanical treatment leads to significant changes in the reaction kinetics and phase formation laws. Particularly, in an activated mixture, the formation of Ni3Al is followed by NiAl intermetallic, in contrast to non-activated mixture, where the reaction proceeds only with the NiAl formation. The both MA in 1 min and addition of 1 wt.% NA decreased the activation energy of the Ni-Al reaction, exhibiting commensurate impact on the effective activation energy value of the Ni-Al system. However, > 3 min MA in the presence of 1 wt.% NA have prohibitive effect on the reaction in the Ni-Al system.

Effects of carbon nano-additives on characteristics of TiC ceramics prepared by field-assisted sintering

Five carbonaceous nano-additives (graphite, graphene, carbon black, carbon nanotubes, and diamond) had different impacts on the sinterability, microstructural evolution, and properties of titanium carbide. In this research, the sintering by spark plasma was employed to produce the monolithic TiC and carbon-doped ceramics under the sintering parameters of 1900 ºC, 10 min, 40 MPa. The carbon black additive had the best performance in densifying the TiC, thanks to its fine particle size, as well as its high chemical reactivity with TiO2 surface oxide. By contrast, the incorporation of nano-diamonds resulted in a considerable decline in the relative density of TiC owing to the graphitization phenomenon, together with the gas production at high temperatures. Although carbon precipitation from the TiC matrix occurred in all samples, some of the added carbonaceous phases promoted this phenomenon, while the others hindered it to some extent. Amongst the introduced additives, carbon black had the most contribution to grain refining, so that a roughly halved average grain size was attained in comparison with the undoped specimen. The highest values of hardness (3233 HV0.1 kg), thermal conductivity (25.1 W/mK), and flexural strength (658 MPa) secured for the ceramic incorporated by 5 wt% nano carbon black.

Nanocarbon Additives Application in the Polyvinyl Chloride Siding Panels Manufacture

With the development of building technologies, there is a need for new finishing materials that must meet the requirements of modern standards. This concerns not only the pricing policy, but also the high quality of promising materials, that first of all, is manifested in strength characteristics. In order to strengthen and preserve the heat-insulating properties and corrosion resistance, it is proposed to introduce schungite of type III of various grades in the formulation of siding panels made of polyvinyl chloride (PVC). The analysis of the quality indicators of PVC panels was carried out and three main indicators were identified: melt flow rate; Charpy impact strength; bending stress. PVC siding panels with the addition of shungite were produced by injection molding. As a result of experimental studies, the dependence of the Charpy impact strength of PVC panel samples without notching and bending stress on the bulk density of schungite was revealed, and scattering diagrams of the dependence of the melt flow rate on the polymerization time and the melt flow rate on the PVC concentration were constructed. The effect of schungite concentration of various grades on the melt flow rate was revealed. The dependence of shungite application as a reinforcing filler on the decrease in the melt flow rate in comparison with the traditional filler is determined.

Effect of particle size, surface area and conductivity of nano-carbon additives on deep discharge lead-acid battery

The effect of carbon nano- and micro-particle additives on performance of lead-acid battery (LAB) was studied by considering two different carbon blacks, both having low electrical conductivity. Full-scale 150 Ah flooded-electrolyte stationary batteries were prepared in a battery manufacturing unit and subjected to deep discharge cyclic conditions at depth-of-discharge (DOD) ~65%. We report that carbon particle size played a significant role in LAB performance. In comparison to nano-size, micron-scale particles demonstrated better results and this was completely in accordance with Pavlov’s findings. Moreover, an improvement in LAB charging regime and its charge return percentage was observed by the inclusion of multi-walled carbon nanotubes (MWCNTs) in negative active material (NAM). Intriguingly, upon testing with 100 Ah deep discharge traction battery by replacing 0.075 wt% of micron additive with MWCNTs, the battery back-up time was increased by half an hour roughly (during C5 discharge with 100% DOD), while its charging time was reduced by 15–25 min, which seems to be significant. Such enhancement in LAB’s charge–discharge efficacy can be attributed to high specific surface area and electrical conductivity of MWCNTs, which with its tubular morphology was helpful in establishing an effective conductive network within NAM. The microscopic analysis confirms the useful dispersion and structural stability of MWCNTs in NAM.

Analysis of the behavior of epoxy composites with carbon nano additives under the influence of high temperatures on fires

The results of research on the thermal stability of epoxy resins modified with carbon nanomaterial as polymer composites matrices are presented. It is shown that modification of binder component of composite materials at deposition of carbon nanomaterials leads to improvement of thermal stability, including decrease of intensity of crystal lattice destruction, decrease of amplitude value of thermal effect, increase of duration of oxidation of material at high temperatures, promotes stable formation of heat-protective and insulating carbonized layer.

Hybrid Redox Flow Cells with Enhanced Electrochemical Performance via Binderless and Electrophoretically Deposited Nitrogen-Doped Graphene on Carbon Paper Electrodes.

Hybrid redox flow cells (HRFC) are key enablers for the development of reliable large-scale energy storage systems; however, their high cost, limited cycle performance, and incompatibilities associated with the commonly used carbon-based electrodes undermine HRFC's commercial viability. While this is often linked to lack of suitable electrocatalytic materials capable of coping with HRFC electrode processes, the combinatory use of nanocarbon additives and carbon paper electrodes holds new promise. Here, by coupling electrophoretically deposited nitrogen-doped graphene (N-G) with carbon electrodes, their surprisingly beneficial effects on three types of HRFCs, namely, hydrogen/vanadium (RHVFC), hydrogen/manganese (RHMnFC), and polysulfide/air (S-Air), are revealed. RHVFCs offer efficiencies over 70% at a current density of 150 mA cm-2 and an energy density of 45 Wh L-1 at 50 mA cm-2, while RHMnFCs achieve a 30% increase in energy efficiency (at 100 mA cm-2). The S-Air cell records an exchange current density of 4.4 × 10-2 mA cm-2, a 3-fold improvement of kinetics compared to the bare carbon paper electrode. We also present cost of storage at system level compared to the standard all-vanadium redox flow batteries. These figures-of-merit can incentivize the design, optimization, and adoption of high-performance HRFCs for successful grid-scale or renewable energy storage market penetration.

Vermicomposting of livestock manure as affected by carbon-rich additives (straw, biochar and nanocarbon): A comprehensive evaluation of earthworm performance, microbial activities, metabolic functions and vermicompost quality

Vermicomposting is an eco-friendly method for treating organic wastes. This study investigated the effects of the addition of straw (S), biochar (B), nanocarbon (N), S + B and S + N to cow dung (CD) on earthworm (Eisenia fetida) performance, microbial properties and vermicompost quality. In general, the earthworm growth rate and cocoon production were enhanced by straw addition, but were inhibited by biochar or nanocarbon addition. However, biochar and nanocarbon increased microbial communities associated with organic matter decomposition, and improved metabolic functions, enzyme activities and vermicompost properties. Moreover, addition of straw in combination with nanocarbon resulted in the highest vermicompost quality index (VQI), and significantly increased the biomass of three different test crops (radish, lettuce and pakchoi). These results indicated that biochar and nanocarbon mainly improved microbial activities, while straw primarily enhanced earthworm performance during vermicomposting. In addition, straw combined with nanocarbon can be used to enhance the agronomic performance of vermicompost.

EFFECT OF NANOCARBON ADDITIVES ON STABILITY OF POLYMER COMPOSITES

This review briefly describes a state of research on the effect of fullerenes and carbon nanotubes (CNTs) on a durability of various polymer composite materials under extreme conditions. Fullerenes C60, C70, fullerene soot and CNTs integrated into the polymer matrix effectively prevent both thermal and thermo-oxidative degradation, as well as photo-oxidation processes. The stabilization mechanism of the carbon nanocompounds (CNC) is likewise and consists of the substantial end-capping termination of oxidation destructive chains on the nanocarbon skeleton. At that, the data array unequivocally indicates the predominant addition of carbon-centered alkyl radicals. Various polymer composite materials based on polyolefins, polyacrylates, polyamides, polycarbonates, elastomers are involved into the consideration. The approaches described are mostly aimed to increase the level of stabilizing activity of the polymer composites using different combinations of nanocarbon additives. The optimal dosage of CNC and interfacial compatibility between the polymer and fillers can significantly increase the heat resistance of the composites. The replacement of carbon atoms in the fullerene molecule with heteroatoms can also change its electronic properties and improve the antiradical and antioxidant activity. Areas for the effective use of fullerene C60 in aqueous media can be significantly expanded by modification with hydrophilic polymers. Thus, the performance of CNC integrated in the polymer composites is similar with those for strong synthetic stabilizers. CNC have good prospects for real industrial applications.

Cu–C Metal Matrix Nanocomposites: Synthesis

An analysis of the results of original research on the synthesis of hybrid composite materials, copper–carbon nanostructures, carried out over the past five years in the laboratories of Peter the Great St. Petersburg Polytechnic University under the scientific supervision of the author, is presented. The features of the formation of the structure and properties of composite materials are considered depending on the synthesis method, the choice and amount of carbon nanoadditives. Possible mechanisms that determine the physical and mechanical properties of materials have been suggested. It has been shown for a number of characteristics taken as an example (hardness, thermal and electrical conductivity) that the entire complex of physical and mechanical properties can be varied in a wide range, which is extremely important for the practical use of hybrid composite materials.

Effect of Nano-Carbon Addition on Angle Dependence of Polystyrene Colloidal Crystal Film

Low angle dependence single green polystyrene colloidal crystal films were prepared by vertical deposition method using polystyrene microspheres with size of 380 ± 10 nm as raw material and further modified by adding nano-carbon. Without nano-carbon addition, the film showed various colors with changing the angle of incident light under natural light. With nano-carbon addition, saturation and angle dependence of the polystyrene colloidal crystal film were remarkably improved. With 0.01 wt % nano-carbon addition, since the stray light of other wavelengths other than the band gap light was absorbed by the added nano-carbon, the film showed only green color under different angles of incident light, suggesting that the film had low angle dependence. It is significant in the research of color behavior and is helpful to obtain single color polystyrene colloidal crystal film.

Durability sensor using low concentration carbon nano additives

In this paper, nanocomposite durability sensors were developed in order to detect the diffusion of chemicals in real-time. Polymer nanocomposite based sensors usually consist of conductive nano-additives such as CNT (carbon nanotube), graphene, carbon black, silver nanoparticles, etc. However, these nanocomposite sensors use a high content of nanomaterials to ensure good conductivity. In this study, a special approach for a chemical sensor with a low concentration (0.1 wt%-2 wt%) carbon nano-additive was carried out and tested in the 1[M] H3PO4 solution. Responding time and electrical resistance of each stage were analyzed against the nano-additives’ concentration. The sensing behavior is represented by the decrease of electrical resistance from 100 MΩ level to 100 Ω level. A numerical multi-stage model was developed to evaluate the formation of the conductive network and its sensing property. The modeling work shows two major parameters affect the sensing behavior: (1) The aspect ratio of conductive nano-additive. (2) Diffusion coefficient ratio of different ions in different phases.

Effects of dimensions and size of carbon nano-additives in water-based lubricants on the tribological behavior for polytetrafluoroethylene (PTFE) friction pair

The tribological performances of two-dimensional graphene oxide (GO), one-dimensional carbon nanotubes (CNTs), zero-dimensional carbon nanoparticles (CNPs) and zero-dimensional carbon dots (CDs) as additives for water-lubricated PTFE/PTFE contacts are investigated, and the effects of dimensions and size on the tribological behavior carbon nano-additives are investigated systematically. The results show that the introduction of carbon nano-additives into water could inhibit slippage and stress crack of PTFE by form of the adhesive layer, but have different influence degree to the tribological actions due to the difference in properties and dimensions. Among all of carbon nano-additive, multilayer GO can be adsorbed and form a compact protective film on the surface of PTFE showing the most excellent tribological performance. CNTs, CNPs and CDs which usually show effect in friction-reducing based on nano-bearing effects, however, an adhesive layer which no slip and shear is observed form when friction occurs and cause undesirable abrasive wear.

The effect of addition of carbon nanoparticles on gasoline to power and fuel consumption

The concerns about the continuity of energy supply have sparked the idea of many people to find things that can be used to save fuel use. One of the popular ways developed at this time is the addition of carbon nanoparticles. Carbon nanoparticles are carbon particles with a range size of 1/1, 000, 000, 000 m. Rice hust nanoparticle carbon with chemical characteristics (magnesium, aluminium, silica, potassium) are non-ferrous metal elements. The addition of carbon nanoparticles in the fuel serves as a catalyst (conductor of heat) in the burning process of the fuel. The carbon chemical content will add carbon to the fuel. The mass of rice hust carbon nanoparticles is which dissolved in gasoline fuel, causing molecules in the fuel to increase mass concentration and make sorter distance between molecules. Carbon nano additives can create micro explosions in the combustion process. Micro explosions will increase the pressure produced in the combustion chamber, also the micro explosion will accelerate the combustion process. With increasing pressure and combustion speed will increase the power produced.

Properties of foamed glass upon addition of nanocarbon and sintering temperatures

ABSTRACTAs a blowing agent, 2–10 wt% of nanocarbon (NC) was added 10 µm glass powder (CaO, MgO, Al2O3, SO3, 83 wt%-SiO2) and sintered at 700–900°C to fabricate foamed glasses with closed pores that were 62–2200 µm. Optical microscopy was used to examine the microstructure and pore size. Compressive strength tester and a heat flow meter were used to examine the changes in mechanical strength and thermal conductivity. The microstructure examination results showed that was performed at 700°C, 297.9–351.3 µm pores were fabricated, and the porosity was 57–63 % in the sample that contained 6–10 wt% NC. At sintering temperatures above 750°C, the pore size increased as the NC content and the sintering temperature increased. The thermal conductivity was maintained at less than 0.28 W/m‧K. Therefore, it is possible to use 6–8 wt% NC as a blowing agent in glass material to produce foamed glass that has closed pores of approximately 500 µm with better or equivalent compressive strength and thermal conductivity properties than existing 1000 µm grade foamed glass, despite being sintered at a temperature of approximately 100°C lower.

Comprehensive evaluation of Paraffin-HDPE shape stabilized PCM with hybrid carbon nano-additives

Thermal energy storage using phase change materials (PCMs) is of great interests in many fields, especially in solar thermal applications. To overcome the leakage problem caused by phase change and the low thermal conductivities of most PCMs, the current study prepared and tested two Paraffin-HDPE-based composites by adding two hybrid Carbon Nano-additives (CNs) fillers: Expanded Graphite-Multi-walled Carbon Nanotube (EG-MWCNT) and Expanded Graphite-Carbon Nanofiber (EG-CNF). A comprehensive evaluation method was first proposed based on the Efficacy Coefficient Method (ECM) to assess the thermal performance of Paraffin-HDPE shape stabilized PCM (SSPCM). Seven individual indexes, including phase change temperature, latent heat, thermal conductivity, leakage rate, specific heat of both solid and liquid phase, and heat storage/heat release rates, were measured and applied to obtain the overall efficacy coefficients of the prepared SSPCM composites. The results showed that in all studied composites, n-octadecane-HDPE/EG-MWCNT composite exhibited the best comprehensive thermal performance with an optimal mass ratio of EG and MWCNT being 4:1.

Experimental study on thermal conductivity of paraffin-based shape-stabilized phase change material with hybrid carbon nano-additives

Thermal energy storage with Phase Change Materials (PCMs) is one of the most potential technologies for energy storage. However the low thermal conductivity of PCMs reduces the heat exchange rate during melting and solidification cycles. This paper studied the effects of two hybrid Carbon Nano-additives (CNs) fillers, that is, Expanded Graphite-Multi-walled Carbon Nano-tube (EG-MWCNT) and Expanded Graphite- Carbon Nano-fiber (EG-CNF), on the thermal conductivity of Paraffin-HDPE SSPCM. From the viewpoints of synergistic thermal enhancement effect and the interfacial thermal resistance, the principle of enhancing thermal conductivity of Paraffin-HDPE/EG-MWCNT and Paraffin-HDPE/EG-CNF composite PCMs was analyzed. A modified Maxwell-Garnett model with a synergy factor η was proposed, which found excellent agreement between model prediction and the experimental data. Compared with the 5 wt% loading of single CN additive EG, the thermal conductivities of hybrid CNs fillers (EG-MWCNT and EG-CNF) Paraffin-HDPE SSPCM had increased by 60% and 21.2% respectively. Within the scope of mass ratios of hybrid CNs fillers in this paper, Paraffin-HDPE/EG-MWCNT composite PCM exhibited superior performance than Paraffin-HDPE/EG-CNF in thermal conductivity with the optimal mass ratio of EG and MWCNT being 4:1.

Modification of Ceramics and Ceramic Glazers with Carbon Nanoadditives, and Properties of the Modified Materials

Modification of Ceramics and Ceramic Glazers with Carbon Nanoadditives, and Properties of the Modified Materials

Effective chemical methods of fire control: new threats and new solutions

This paper discusses the prospective flame retardant systems for polymeric materials, while considering the environmental issues they create. Polymer nanocomposites with carbon nano-additives and layered silicates are presented as a new type of flame retardant system which exhibits a synergistic effect flame retardancy for traditional polymer thermoplasts. Particular attention is paid to the novel intumescent flame retardants based on the oxidized renewable raw materials, which can be successfully used in the manufacture of multi-purpose timber construction and polymer materials.