FEW WALLED CARBON NANOTUBE PRODUCTION IN LARGE-SCALE BY NANO-AGGLOMERATE FLUIDIZED-BED PROCESS

NANO ◽  
2008 ◽  
Vol 03 (01) ◽  
pp. 45-50 ◽  
Author(s):  
QIANG ZHANG ◽  
HAO YU ◽  
YI LIU ◽  
WEIZHONG QIAN ◽  
YAO WANG ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
High Performance ◽  
Large Scale ◽  
Outer Diameter ◽  
Scale Production ◽  
Raman Spectrometry ◽  
Activity Catalyst ◽  
Methane Cracking ◽  
Fluidized Bed Process ◽  
Walled Carbon Nanotubes

Few walled carbon nanotubes (FWCNTs) have been successfully synthesized using a nano-agglomerate fluidized-bed process. FWCNTs can be obtained by fluidization of Fe ( Co / Ni )/ Mo / MgO catalysts at a high temperature with methane cracking in a nano-agglomerate fluidized-bed reactor. The products were mainly 2 to 5 walled CNTs with an outer diameter of 1–7 nm in high purity, as revealed by Raman spectrometry, SEM, and HRTEM analysis. Two keys were crucial for this process. The first key was to get the small size of activity catalyst particles which was realized by Mo addition in catalyst. The graphitization of FWCNTs strongly depended on the composition of catalyst. Fe / Mo / MgO catalyst showed the highest activity and the FWCNT product with the best graphitization. Another key for this process was that the particles must be kept in fluidized state during FWCNT formation. Detailed process information was reported in this article, which showed a potential way for the large scale production of FWCNTs, thereby the urgent need for FWCNTs in high performance will be overcome.

Large-scale production of single-walled carbon nanotubes by induction thermal plasma

2007 ◽  
Vol 40 (8) ◽  
pp. 2375-2387 ◽  
Author(s):  
Keun Su Kim ◽  
German Cota-Sanchez ◽  
Christopher T Kingston ◽  
Matej Imris ◽  
Benoit Simard ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Plasma ◽  
Large Scale ◽  
Single Walled Carbon Nanotubes ◽  
Scale Production ◽  
Single Walled Carbon ◽  
Induction Thermal Plasma ◽  
Large Scale Production ◽  
Walled Carbon Nanotubes

scholarly journals Continuous, Strong, Porous Silk Firoin-Based Aerogel Fibers toward Textile Thermal Insulation

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1899 ◽  
Author(s):  
Haiwei Yang ◽  
Zongqian Wang ◽  
Zhi Liu ◽  
Huan Cheng ◽  
Changlong Li
Keyword(s):  
Heat Transfer ◽  
Thermal Insulation ◽  
Hollow Fiber ◽  
High Performance ◽  
Large Scale ◽  
Low Density ◽  
Potential Candidate ◽  
Scale Production ◽  
Insulation Material ◽  
High Porosity

Aerogel fiber, with the characteristics of ultra-low density, ultra-high porosity, and high specific surface area, is the most potential candidate for manufacturing wearable thermal insulation material. However, aerogel fibers generally show weak mechanical properties and complex preparation processes. Herein, through firstly preparing a cellulose acetate/polyacrylic acid (CA/PAA) hollow fiber using coaxial wet-spinning followed by injecting the silk fibroin (SF) solution into the hollow fiber, the CA/PAA-wrapped SF aerogel fibers toward textile thermal insulation were successfully constructed after freeze-drying. The sheath (CA/PAA hollow fiber) possesses a multiscale porous structure, including micropores (11.37 ± 4.01 μm), sub-micron pores (217.47 ± 46.16 nm), as well as nanopores on the inner (44.00 ± 21.65 nm) and outer (36.43 ± 17.55 nm) surfaces, which is crucial to the formation of a SF aerogel core. Furthermore, the porous CA/PAA-wrapped SF aerogel fibers have many advantages, such as low density (0.21 g/cm3), high porosity (86%), high strength at break (2.6 ± 0.4 MPa), as well as potential continuous and large-scale production. The delicate structure of multiscale porous sheath and ultra-low-density SF aerogel core synergistically inhibit air circulation and limit convective heat transfer. Meanwhile, the high porosity of aerogel fibers weakens heat transfer and the SF aerogel cellular walls prevent infrared radiation. The results show that the mat composed of these aerogel fibers exhibits excellent thermal insulating properties with a wide working temperature from −20 to 100 °C. Therefore, this SF-based aerogel fiber can be considered as a practical option for high performance thermal insulation.

scholarly journals Superior Pseudocapacitive Storage of a Novel Ni3Si2/NiOOH/Graphene Nanostructure for an All-Solid-State Supercapacitor

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jing Ning ◽  
Maoyang Xia ◽  
Dong Wang ◽  
Xin Feng ◽  
Hong Zhou ◽  
...  
Keyword(s):  
Solid State ◽  
High Performance ◽  
Large Scale ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Specific Area ◽  
High Energy ◽  
Scale Production ◽  
Free Standing

Abstract Recent developments in the synthesis of graphene-based structures focus on continuous improvement of porous nanostructures, doping of thin films, and mechanisms for the construction of three-dimensional architectures. Herein, we synthesize creeper-like Ni3Si2/NiOOH/graphene nanostructures via low-pressure all-solid melting-reconstruction chemical vapor deposition. In a carbon-rich atmosphere, high-energy atoms bombard the Ni and Si surface, and reduce the free energy in the thermodynamic equilibrium of solid Ni–Si particles, considerably catalyzing the growth of Ni–Si nanocrystals. By controlling the carbon source content, a Ni3Si2 single crystal with high crystallinity and good homogeneity is stably synthesized. Electrochemical measurements indicate that the nanostructures exhibit an ultrahigh specific capacity of 835.3 C g−1 (1193.28 F g−1) at 1 A g−1; when integrated as an all-solid-state supercapacitor, it provides a remarkable energy density as high as 25.9 Wh kg−1 at 750 W kg−1, which can be attributed to the free-standing Ni3Si2/graphene skeleton providing a large specific area and NiOOH inhibits insulation on the electrode surface in an alkaline solution, thereby accelerating the electron exchange rate. The growth of the high-performance composite nanostructure is simple and controllable, enabling the large-scale production and application of microenergy storage devices.

scholarly journals Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5558
Author(s):  
Dimitra Vernardou ◽  
Charalampos Drosos ◽  
Andreas Kafizas ◽  
Martyn E. Pemble ◽  
Emmanouel Koudoumas
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Large Scale ◽  
Electrode Materials ◽  
Low Cost ◽  
Aqueous Media ◽  
Chemical Vapour ◽  
Cost Effective ◽  
Scale Production ◽  
Environmentally Safe

The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.

Porous micro-spherical LiFePO4/CNT nanocomposite for high-performance Li-ion battery cathode material

RSC Advances ◽  
2015 ◽  
Vol 5 (47) ◽  
pp. 37830-37836 ◽  
Author(s):  
Wei Wei ◽  
Linlin Guo ◽  
Xiaoyang Qiu ◽  
Peng Qu ◽  
Maotian Xu ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Cathode Material ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Scale Production ◽  
Li Ion Battery ◽  
Excellent Performance ◽  
Large Scale Production ◽  
Li Ion

Although many routes have been developed that can efficiently improve the electrochemical performance of LiFePO4 cathodes, few of them meet the urgent industrial requirements of large-scale production, low cost and excellent performance.

scholarly journals Environmental and Economic Analysis of FDM, SLS and MJF Additive Manufacturing Technologies

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4161 ◽  
Author(s):  
Vincenzo Tagliaferri ◽  
Federica Trovalusci ◽  
Stefano Guarino ◽  
Simone Venettacci
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Large Scale ◽  
Fused Deposition Modeling ◽  
Production Capacity ◽  
Optimal Choice ◽  
Scale Production ◽  
Fused Deposition ◽  
Manufacturing Technologies ◽  
The Impact

In this study, the authors present a comparative analysis of different additive manufacturing (AM) technologies for high-performance components. Four 3D printers, currently available on the Italian national manufacturing market and belonging to three different AM technologies, were considered. The analysis focused on technical aspects to highlight the characteristics and performance limits of each technology, economic aspects to allow for an assessment of the costs associated with the different processes, and environmental aspects to focus on the impact of the production cycles associated with these technologies on the ecosystem, resources and human health. This study highlighted the current limits of additive manufacturing technologies in terms of production capacity in the case of large-scale production of plastic components, especially large ones. At the same time, this study highlights how the geometry of the object to be developed greatly influences the optimal choice between the various AM technologies, in both technological and economic terms. Fused deposition modeling (FDM) is the technology that exhibits the greatest limitations hindering mass production due to production times and costs, but also due to the associated environmental impact.

scholarly journals High performance ceramic stones on the basis of by-products of waste heaps - screenings and coal slurry

2019 ◽  
Vol 135 ◽  
pp. 03017
Author(s):  
Khungianos Yavruyan ◽  
Vladimir Kotlyar ◽  
Evgeniy Gaishun ◽  
Anastasia Okhotnaya ◽  
Elizaveta Lotoshnikova ◽  
...  
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Raw Materials ◽  
Minimum Cost ◽  
Coal Slurry ◽  
Manufacturing Cost ◽  
Scale Production ◽  
General Description ◽  
Technological Properties ◽  
Molding Process

General description of coal dumps products processing is described: medium factional materials - screenings that do not contain carbon; kiln fractional - coal sand, coal containing up to 30%; petty factional - coal slurries, coal containing up to 50% are given. Ceramic kilns and technological properties of processing coal dumps products are given. Compositions of raw mixtures for obtaining products with a compressive strength of 10-15 MPa and density less than 800 kg / m3, and considering the fact that the molding process is carried out semi-rigid extrusion and the necessity of minimum costs for firing is defined. Depending on the technological properties of screenings, depending on the degree of grinding and firing temperature is taken into account. Flow production of modern equipment is pointed out. Technical and economic indicators showing high profitability and the prospect of large-scale production of clay tiles on the basis of coal dumps processing products due to minimal manufacturing cost are mentioned. The carried out results of the work allowed to choose the raw materials and to develop the technological scheme of production of high-performance ceramic stones with a minimum cost. Implementation of the results in practice will create a highly profitable production and make the Rostov region a major manufacturer of ceramic wall.

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