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Rosseter is producing raw deposits of two main nanotube products,

Ros1 - short Multi Wall Nano Tubes (sh‑MWNTs) and
Ros2 - ଩t헎Ts, sp‑MWNTs

In TEM pictures the nanotube deposits appear as mixtures of the sh‑MWNTs and carbon polyhedral nanoparticles, with admixtures of different graphitic carbons and short Single Wall Nano Tubes (sh‑SWNTs).

The rest of Rosseter
's products (Ros3-Ros5) are by‑products of the two main processes. The by‑products contain few nanotubes and are mostly composed of different forms of disordered graphite (DOG) and Graphite Nano Fibers (GNFs).

Ros1, as produced

Ros1 is produced in our main process with no use of catalysts.
Most part of sh‑MWNTs in Ros1 seem to be nested (Russian doll‑like structure) MWNTs having semi‑spherical and conical-like (or faceted) caps [see HR-TEM in Fig.3,a,b].
Ros1 contains (see typical TEM images in Fig.4 and Fig.5) 50-80wt% of MWNTs and 15-35% of carbon polyhedral nanoparticles, and the rest are different forms of disordered graphite including single graphite sheets, graphite platelets, 駨t soot஡noscales, traces of SWNTs (Fig.3c), etc.
Inorganic impurities are not higher than 0.5wt% and can be easily removed by successful washing in inorganic acids (HCl, HNO3, H2SO4).
Typical X-Ray Diffraction patterns and Micro-Raman spectra are shown in Fig.6. XRD reveals two main interlayer distances in the sh‑MWNTs, 0.341 and 0.345 nm (Fig.6). HR-TEM reveals essentially increased interlayer distances (up to 0.375 nm), especially, for thinner sh‑MWNTs (Fig.7,d).
MWNTs튠 length and diameter distributions are characterized by three-modal distributions with maximums at ~200, 300 and 500 nm for lengths, ~6.5, 12 and 20 nm for outer diameters and 2.6, 4.0 and 6.7 nm for inner diameters (the distributions are presented in Fig.7,d)

Ros1 - Field Electron Emission

The MWNTs䩡meter distribution provides excellent Field Electron Emission (FEE) properties. Rough powders of Ros1 start Field Electron Emission (EE) at a threshold of 2‑2.5V/micron, demonstrating intensity currents of 0.5-1 mA/cm2 at electric fields of 3‑3.5 V/micron.
Typical FEE I-V-curves are shown in Fig.8 (under the test a powdered Ros1 sample is pressed into a hollow with a cross section of 1mm2).
The FEE parameters strongly depend on admixtures of the graphitic forms (see Fig.9). Separation of the graphitic forms allows improving FEE further

Ros1 - Composites

The MWNTs쥮gth distribution provides a very good dispersivity (see TEM in Fig.5), solubilization and functionalization of the MWNTs that facilitates producing Composites possessing improved mechanical characteristics even at very low loads of raw Ros1.
Loads of just ~1% of raw Ros1 in PVA improve Young modulus, strength tensile, toughness and electric conductivity in 1.5, 1.75, 2 and 104 times, respectively, in comparison with the blank PVA film (Fig.10,a,b)(Fig.10,c).

Metal composites prepared by electro-codeposition of metals and our sh‑MWNTs (Ros1) exhibit a remarkable improvement of hardness and a decrease of the wear volume in comparison with the blank metal matrix.

Ros1 - BET Surface Area

BET surface area is 6.5-10 m2/g (rough powders). Pore area is about 90-95% of the BET (see graphs in Fig.11).
Hydrogen storage in 10g-powder-samples at room temperature and pressure of ~100 atm  is low, ~ 0.1-0.2wt%. Better storage is expected for oxidized nanotubes.
The tubes are well graphitised and can sustain long oxidation in air and acids (H2SO4, HNO3, HCl, HF/HNO3, etc). In air perceptible losses of weight (≥2-3rel.%) are achieved for time less than 10-15 min at temperatures higher than 600oC. Typical TGA are shown in Fig.12.
The MWNTs usually have one semispherical and one conical cap. Under a proper oxidation (for instant, in air at ~600oC for ~ 45-60 min) the semispherical caps are opened in first turn leaving the conical ones almost intact (HR-TEM in Fig.13).
Further characteristics of Ros1 are coming soon

Ros1-p, purified (under development)

This is a product mainly containing the MWNTs and polyhedral nanoparticles.
A new technique of quantitative separation of the MWNTs from the graphitic carbons is under development.
The technique allows separating large quantities of raw Ros1 powders into 2 fractions, the MWNTs & nanoparticles (see TEM in Fig.14) and the graphitic carbons (see TEM in Fig.15). As a result, FEE from Ros1‑p is highly improved (Fig.9).

Ros2, as produced (under development)

Ros2 is produced in a modified process with use of Co/Ni catalysts.
Ros2 (as produced) contains ~50 wt% of short MWNTs, ~ 20% of carbon polyhedral nanoparticles and the rest are different graphitic forms (highly-disordered graphite, single graphite sheets, graphite platelets, 駨t soot৲aphitic scales, traces of SWNTs, etc (see typical TEM images in Fig.16, Fig.17,Fig.18).
In HR‑TEM pictures (Fig.19, Fig.20) the most part of Ros‑2 MWNTs exhibit asymmetrical wall-thickness and the extra thickness is concentrated in some isolated singular fringe spacings, which are concentrated in one wall of the MWNTs. This effect can be explained by assuming that the sp‑MWNTs partially consist of scrolls instead of nested cylindrical tubules. The scrolls introduce extra‑space between the layers, the space is usually double of the normal value, i.e. it is ~0.7 nm, but sometimes the spaces of ~1.05 nm and even ~1.4 nm are seen in HR‑TEM pictures of the sp‑MWNTs.
In comparison with Ros1 sh‑MWNTs Ros2 MWNTs are essentially elongated and thickened (see length and diameter distributions in Fig.7).
Upon opening the entries by a careful oxidation, the extra‑space provides additional channels for Gas & Energy storage

Further characteristics of Ros2 are coming soon

Ros3

A by-product of the modified process (Ros2) appears as mainly composed of DOG in shapes of spherical curly lumps, platelets and single sheets (Fig.21). Also different forms of GNFs, partially graphitized soot particles, 駨t㯯t and Co/Ni nanoparticles are seen in typical TEM images of Ros3 [Fig.22].
Being especially oxidized and annealed, Ros-3 samples of 10 grams demonstrated high Hydrogen uptakes at room temperature and moderate pressures (Fig.23).
Further characteristics of Ros3 are coming soon

Ros4

Gaseous hydrocarbons released in both processes (Ros1/Ros2) are partially converted in Ros4 which is composed of different forms of DOG with traces of MWNTs (Figs.24,a,b,c).
Ros4 is produced as monolithic dense (~1.7g/cm3) thin (50-200 μm) coatings over refractory metals and can be produced as pipes with inner diameters of 1-3 mm and wall thicknes of 50-500 μm.
Powdered Ros4 demonstrates a rather stable but low FEE.
Further characteristics of Ros4 are coming soon

Ros5

A by‑product of our main process (Ros1) is very similar to Ros3 but it contains no metal nanoparticles and few GNFs (see Fig.25). Short SWNTs are traces in Ros5 as well.
Fig.26 shows typical HR-TEM images of DOG sheets and curly lumps.
Further characteristics of Ros5 are coming soon

Ros6

Gaseous hydrocarbons released in the modified process are partially converted in Ros6. In TEM pictures Ros6 appears as a mixture of long GNFs, bimodal soot particles and Co/Ni nanoparticles (Fig.27).
HR‑TEM shows herringbone structure of the GNFs (Fig.28) and partially‑graphitized structure of the soot particles (Fig.29).
Further characteristics of Ros6 are coming soon.

 


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