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            Custom-made Ceramic
            and Glass Components

            Boron Nitride Nanotubes

            Boron Nitride Nanotube is a next-generation nano-material which will lead the 4th industrial revolution. 

            Boron nitride nanotubes (BNNTs) are another form of boron nitride. They were predicted in 1994 and experimentally discovered in 1995 by Chopra N. G. et al[1].

            Structurally they are like carbon nanotubes, which are cylinders with sub-micrometre diameters and micrometre lengths, except BNNT is composed of hexagonal boron nitride constructed by combining boron and nitrogen, whereas Carbon Nanotubes (CNTs) have a carbon constructed hexagonal structure.

            The key features that represent BNNTs are light weight and mechanical strength like CNTs.

            However, the properties of BN nanotubes are very different: whereas carbon nanotubes can be metallic or semiconducting depending on the rolling direction and radius, a BN nanotube is an electrical insulator with a bandgap of ~5.5 eV.

            In addition, a layered BN structure is much more thermally and chemically stable than a graphite layered structure. BNNTs are demonstrating superior thermal and chemical stability than CNTs and they have 200,000 times higher thermal neutron absorption capacity than that of CNTs.

            BNNTs VS CNTs (overview)

             

            Carbon Nanotubes (CNTs)

            Boron Nitride Nanotubes (BNNTs) 

            Electrical properties

            Metallic or semiconducting        

            Electrically insulating
            (~ 5.5 eV band gap)

            Mechanical properties
            (Young’s modulus)

            1.33 TPa

            1.18 TPa

            Thermal conductivity

            60 – 40,000 W/mK

            ~ 3,000 W/mK (Cu=400 W/mK)

            Thermal oxidation resistance

            Stable up to 300–400˚C in air

            Stable up to 800˚C in air

            Thermal neutron
            absorption cross-section

            C=0.0035 b
            (barn=10-24 cm2)

            B11=767 b (B10=~3800 b), N=1.9 b
            Excellent neutron shielding

            Polarity

            Covalent bond,
            (No dipole)

            Permanent dipole,
            Piezoelectric (0.25–0.4 C/m2)

            Biomedical

            Cytotoxic

            Non-cytotoxic

            Colour

            Black

            White / Gray

            Surface morphology

            Smooth

            Corrugated       

            Coefficient of Thermal Expansion

            -1x10-6

            -1x10-6

            Similarities

            Strength, Stiffness, Thermal conductivity, Aspect ratio, Sp2 bond, Structures

            Applications:

            Electric insulation thermal conducting materials (IT):

            Recently, IT industries are facing a challenge to solve the heat dissipation issue which has been resulted from the high integration, miniaturization, multi-functional and lighter weight of electronic products. In this case, the heat released causes malfunction and shortens the lifetime of the device.

            An efficient heat dissipation is critical technological factor in the IT and electronics industry. A solution to the above problem can be an electrically insulating heat-dissipating epoxy-based composite material containing BNNT.

            • Electrical insulation / Heat radiating sheet / Adhesive material
            • Highly bright LED packing materials
            • Piezoelectric sensors (energy harvesting)
            • Ultra-small ultraviolet laser / Nano cable
            • Visible light emitter, etc.

            High temperature structural materials (Nuclear and Space)

            BNNT has superior thermal and chemical stability than CNT and it has 200,000 times higher thermal neutron absorption capacity than that of CNT, enabling it to be used as a shielding lightweight structural material in the aerospace industry requiring surpassing radiation shielding performance.  

            In addition, BNNT is considered to be one of the most suitable materials for the containers of radioactive waste which has been accumulated day by day because of nuclear power plant operation.    Neutron shield and absorber. The improvement is due to strong neutron absorption by 10B. 

            •     Light and tough structural materials for space and artificial satellite
            •     Super plasticity ceramic for high temperature
            •     Aircraft / Reinforced ceramic material for spacecraft
            •     Neutron detection sensor for high temperature

            BNCT drug target (Biomedical)

            Toxicological investigations on BNNTs are demonstrating that the enhanced chemical inertia of BN nanotubes favours biocompatibility. As a result, their use in the biomedical field was suggested both as nano-carriers and as nano-transducers

            • BNCT drug target
            • Drug delivering agent for cancer (electroporation)
            • Non-cytotoxic nerves/bones regenerating drug delivering agent, etc.

            Desalination membrane (Energy)

            •     Hydrogen storage
            •     Desalination membrane
            •     Electric insulating flame retarding cable
            •     Solar sell coating materials

            Goodfellow supplies two grades of BNNTs powder:

            • Product before chemical purification with purity of 70% or higher. It is aimed at customers who wish to use BNNT product for their applied research.
            • Product which is highly purified BNNT obtained by a specific heat treatment process with purity of 90wt% or higher. It is aimed at researchers who will conduct characteristic research through high purity products.

            Goodfellow has other forms of Boron Nitride (BN) as well:

            • Hexagonal-Boron Nitride powder
            • Single Crystal (2D)

            And in sheets, tubes and rods in the following grades:

            • Pyrolytic BN
            • Hot Pressed BN
            • Hot Isostatic Pressed

             

            [1] Chopra, N. G.; et al. (1995). "Boron Nitride Nanotubes". Science. 269 (5226): 966–7. doi:10.1126/science.269.5226.966.

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