Process and apparatus for synthesis of nanotubes

The invention relates to a process for formation of carbon nanotubes. The process comprises laser ablation of a bulk metal catalyst within a hydrocarbon solution to produce a feedstock containing metal catalyst nanoparticles. The feedstock is atomizing to form a feedstock aerosol. The aerosol is heated to form naotubes. An apparatus for forming carbon nanotubes is also disclosed. Nanoparticles formed in the feedstock according to the invention can be controlled to achieve a narrow size distribution, which ultimately allows for good control over size and chirality of the nanotubes formed.

Process and apparatus for synthesis of nanotubes

The invention relates to a process for formation of carbon nanotubes. The process comprises laser ablation of a bulk metal catalyst within a hydrocarbon solution to produce a feedstock containing metal catalyst nanoparticles. The feedstock is atomizing to form a feedstock aerosol. The aerosol is heated to form naotubes. An apparatus for forming carbon nanotubes is also disclosed. Nanoparticles formed in the feedstock according to the invention can be controlled to achieve a narrow size distribution, which ultimately allows for good control over size and chirality of the nanotubes formed.

PROCESS AND APPARATUS FOR PURIFYING BNNT

Provided is a process and an apparatus for purifying boron nitride nanotube (BNNT) materials. The process involves the use of a halogen gas to remove halogen-reactive impurities from boron nitride nanotube (BNNT) materials in a single step with minimal interactions to produce structurally pristine BNNT. Gaseous byproducts are produced that 5 can be removed without the need for solution phase treatments. Yield efficiencies and purity of recovered BNNT are high compared to the other known methods of purification for BNNT material. 1. A process for purifying boron nitride nanotubes , the process comprising:contacting a solid boron nitride nanotube (BNNT) material containing boron nitride nanotubes and impurities with a halogen gas at a temperature of 380° C. or greater, the impurities reacting with the halogen gas to produce gaseous halogen-containing byproducts; and,removing the gaseous halogen-containing byproducts and unreacted halogen gas from the solid boron nitride nanotube material to produce purified boron nitride nanotubes.2. The process of conducted under dry conditions.3. The process of claim 1 , wherein the halogen gas is chlorine claim 1 , bromine claim 1 , or a mixture of chlorine and bromine.4. The process of claim 1 , wherein the halogen gas comprises chlorine and the temperature is between 450° C. and 1250° C.5. The process of claim 4 , wherein the temperature is between 600° C. and 1050° C.6. The process of claim 4 , wherein the temperature is between 850° C. and 1250° C.7. The process of claim 1 , wherein the impurities comprise boron-containing impurities.8. The process of claim 1 , wherein the purity and crystallinity of BNNT material recovered from the process improves as the temperature is increased up to a maximum temperature of 1250° C.9. The process of claim 7 , wherein the impurities removed comprise hexagonal boron nitride.10. The process of claim 7 , wherein the impurities removed comprise defective BNNT material.11. The process of claim 1 ...

Security device

A security device comprising one or more printed or transferred first areas (5), each first area having one or more first colours; and one or more printed or transferred second areas (4), each second area having one or more second colours. At least one of the first and second areas (5, 4) comprises a discontinuous pattern, and the first area or areas (5) surrounds the second area or areas (4), each first area being distinguishable from the second area or areas. The first area(s) and/or second area(s) define an image (6). A camouflage pattern (40) is provided over the image (6) and at least an adjacent region surrounding the image, the camouflage pattern having a colour and pattern such that in combination with the first and second areas, it renders the image substantially invisible when viewed under reflected light but visible when viewed in transmission.

Monopulse array system with air-stripline multi-port network

MONOPULSE ARRAY SYSTEM WITH AIR-STRIPLINE MULTI-PORT NETWORK ABSTRACT OF THE DISCLOSURE An array system with radiating elements and a wideband monopulse power divider network with dual channel input ports and multiple output ports. Each input channel of the network excites a uniquely different RF amplitude and phase distribution out of each of the corresponding "n" output ports. All ports are matched and isolated from each other across a wide instantaneous frequency. Also the RF power distribution will track in amplitude and phase across a wide frequency band. This is achieved through a special arrangement of air-stripline matched power dividers, attenuator, phase shifters, and Magic-Tee couplers. The output ports of the network can be connected directly to the radiating elements or to partitioned feed circuits which are in turn connected to sub-sets of the radiating elements.

Security device

Security document

A security document has a first region (2) and an adjacent second region (3), the regions defining a security device. Opposite sides of the first region (2) are provided with first and second, complementary indicia (Image 1, Image 2) registered with respect to one another, the first region (2) being sufficiently transparent that both the first and second indicia are viewable from either side of the document under reflected light. Third indicia (Image 3) are provided on the second region (3) on the same side of the document, registered with, and complementary to, the first indicia (Image 1), and fourth indicia (Image 4) are provided on the second region (3) on the same side of the document, registered with, and complementary to, the second indicia (Image 2), the third and fourth indicia also being complementary to and registered with respect to one another. The second region (3) is sufficiently opaque such that when the document is viewed under reflected light only the third or fourth indicia facing the observer are visible, but is sufficiently transparent that when the document is viewed from either side under transmitted light, both the third and fourth indicia are visible.

Security document

A security document has a first region and an adjacent second region, the regions defining a security device. Opposite sides of the first region are provided with first and second, complementary indicia registered with respect to one another, the first region being sufficiently transparent that both the first and second indicia are viewable from either side of the document under reflected light. Third indicia are provided on the second region on the same side of the document, registered with, and complementary to, the first indicia, and fourth indicia are provided on the second region on the same side of the document, registered with, and complementary to, the second indicia, the third and fourth indicia also being complementary to and registered with respect to one another. The second region is sufficiently opaque such that when the document is viewed under reflected light only the third and fourth indicia facing the observer are visible, but is sufficiently transparent when the document is viewed from either side under transmitted light, both the third and fourth indicia are visible.

Security document

A security document has a first region (2) and an adjacent second region (3), the regions defining a security device. Opposite sides of the first region (2) are provided with first and second, complementary indicia (Image 1, Image 2) registered with respect to one another, the first region (2) being sufficiently transparent that both the first and second indicia are viewable from either side of the document under reflected light. Third indicia (Image 3) are provided on the second region (3) on the same side of the document, registered with, and complementary to, the first indicia (Image 1), and fourth indicia (Image 4) are provided on the second region (3) on the same side of the document, registered with, and complementary to, the second indicia (Image 2), the third and fourth indicia also being complementary to and registered with respect to one another. The second region (3) is sufficiently opaque such that when the document is viewed under reflected light only the third or fourth indicia facing the observer are visible, but is sufficiently transparent that when the document is viewed from either side under transmitted light, both the third and fourth indicia are visible.

Security device

Process and apparatus for purifying bnnt

Provided is a process and an apparatus for purifying boron nitride nanotube (BNNT) materials. The process involves the use of a halogen gas to remove halogen-reactive impurities from boron nitride nanotube (BNNT) materials in a single step with minimal interactions to produce structurally pristine BNNT. Gaseous byproducts are produced that 5 can be removed without the need for solution phase treatments. Yield efficiencies and purity of recovered BNNT are high compared to the other known methods of purification for BNNT material.

Fig- ure

Process and apparatus for purifying bnnt

Provided is a process and an apparatus for purifying boron nitride nanotube (BNNT) materials. The process involves the use of a halogen gas to remove halogen-reactive impurities from boron nitride nanotube (BNNT) materials in a single step with minimal interactions to produce structurally pristine BNNT. Gaseous byproducts are produced that 5 can be removed without the need for solution phase treatments. Yield efficiencies and purity of recovered BNNT are high compared to the other known methods of purification for BNNT material.

Verfahren und vorrichtung für die synthese von nanoröhren

Process and apparatus for synthesis of nanotubes

The invention relates to a process for formation of carbon nanotubes. The process comprises laser ablation of a bulk metal catalyst within a hydrocarbon solution to produce a feedstock containing metal catalyst nanoparticles. The feedstock is atomizing to form a feedstock aerosol. The aerosol is heated to form naotubes. An apparatus for forming carbon nanotubes is also disclosed. Nanoparticles formed in the feedstock according to the invention can be controlled to achieve a narrow size distribution, which ultimately allows for good control over size and chirality of the nanotubes formed.

Methods and systems for preparing multimetal alloy nanoparticles

The present disclosure relates to a method and system for preparing multimetal alloy nanoparticles (MMA NPs) such as high entropy alloy nanoparticles (HEA NPs). The method comprises: introducing a metal source comprising a plurality of metals into a thermal zone of a plasma torch to obtain a metal vapour comprising the plurality of metals; substantially homogenizing the metal vapour by plasma expansion and turbulence; cooling the metal vapour to co-nucleate and co-condense the MMA NPs; and collecting the MMA NPs. The system comprises a reactor comprising a reaction chamber; a plasma torch; an inlet for introducing a multimetal source to the plasma torch; the reaction chamber configured to substantially homogenize metal vapour by creating one or more of plasma expansion or turbulence; the reactor configured to cool the metal vapor to co-nucleate and co-condense the MMA NPs; and a collecting device.