What is the structure of nanotubes?
The structure of a carbon nanotube is formed by a layer of carbon atoms that are bonded together in a hexagonal (honeycomb) mesh. This one-atom thick layer of carbon is called graphene, and it is wrapped in the shape of a cylinder and bonded together to form a carbon nanotube.
What are nanotubes GCSE?
A nanotube is like a layer of graphene, rolled into a cylinder. The length of a nanotube is very long compared to its width, so nanotubes have high length to diameter ratios. Nanotubes have high tensile strength , so they are strong in tension and resist being stretched.
What is the shape of a nanotube?
Carbon Nanotubes (CNTs) are cylindrical shells made, in concept, by rolling graphene sheets into a seamless cylinder.
Are nanotubes giant covalent structures?
Like graphene, nanotubes are strong, and they conduct electricity because they have delocalised electrons. Buckyballs are spheres or squashed spheres of carbon atoms. They are made up of large molecules but do not have a giant covalent structure.
What type of structure for metallic nanotubes have?
The structure of CNT consists of enrolled cylindrical graphitic sheet (called graphene) rolled up into a seamless cylinder with diameter of the order of a nanometer. It is understood that CNT is the material lying in between fullerenes and graphite as a quite new member of carbon allotropes (Tanaka et al., 1999).
What type of structure for metallic nanotubes have *?
C. D. Explanation: the cnts are often a mixture of semiconducting and metallic tubes. while the metallic tubes have armchair structure, the semiconducting tubes have a chiral structure.
Are nanotubes simple molecular structure?
Nanotubes are essentially a single layer of graphite (or a molecule of graphene) wrapped around to form an elongated tube-like molecule, they only consist of hexagonal rings throughout the sides of the nanotubes.
What is meant by a nanotube?
Definition of nanotube : a microscopic tube whose diameter is measured in nanometers especially : one of pure carbon : buckytube.
What is a nanotube made of?
1 Carbon-Based Nanotubes. Carbon nanotubes (CNTs) are the latest attraction in nanopharmacology. These unique carbon-based materials are made of thin graphite sheets with condensed benzene rings into a seamless tubular hollow cylinder [56]. CNTs are prepared from sp2 hybridized three-dimensional nanoscale tubes.
Which structure of carbon nanotube is metallic?
For a given (n,m) nanotube, if n = m, the nanotube is metallic; if n − m is a multiple of 3 and n ≠ m, then the nanotube is quasi-metallic with a very small band gap, otherwise the nanotube is a moderate semiconductor. Thus, all armchair (n = m) nanotubes are metallic, and nanotubes (6,4), (9,1), etc.
Are nanotubes molecules?
Carbon nanotubes (CNTs) are cylindrical molecules that consist of rolled-up sheets of single-layer carbon atoms (graphene).
What type of structure for metallic nanotubes have Mcq?
The metallic tubes have which kind of structure? Explanation: The CNTs are often a mixture of semiconducting and metallic tubes. While the metallic tubes have armchair structure, the semiconducting tubes have a chiral structure. 7.
What is the structure of carbon nanotubes?
In carbon nanotubes, each carbon atom is surrounded by three other carbon atoms through covalent bonds. These carbon-carbon covalent bonds forms lattice in the shape of hexagons. The crystalline structure of carbon nanotubes exists in the form of regular hexagons. Carbon nanotubes are elastic.
What are the properties of nanotubes?
Nanotubes have high tensile strength, so they are strong in tension and resist being stretched. Like graphene, nanotubes are strong and conduct electricity because they have delocalised electrons. These properties make nanotubes useful for nanotechnology, electronics and specialised materials.
How are nanotubes formed from graphite?
Nanotubes are formed by folding or rolling two-dimensional graphite into a cylindrical shape structure. Nanotubes are hollow from inside. The diameter of the nanotube is around 1-3 nanometers. The length of the carbon nanotube is much higher than its diameter.
What are the applications of carbon nanotubes in engineering?
Engineering materials using carbon nanotubes as additives have exhibited capability to make plastic composites with enhanced electrical conductivity and mechanical strength. For biomedical applications, carbon nanotubes show promise as vehicles for targeted drug-delivery and nerve cell regeneration.