Search results
Results from the WOW.Com Content Network
Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp 2 bonds formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (9,100,000 psi).
A nanotube is a nanoscale cylindrical structure with a hollow core, typically composed of carbon atoms, though other materials can also form nanotubes. Carbon nanotubes (CNTs) are the most well-known and widely studied type, consisting of rolled-up sheets of graphene with diameters ranging from about 1 to tens of nanometers and lengths up to ...
A single-walled carbon nanotubes (SWCNT) can be envisioned as strip of a graphene molecule (a single sheet of graphite) rolled and joined into a seamless cylinder.The structure of the nanotube can be characterized by the width of this hypothetical strip (that is, the circumference c or diameter d of the tube) and the angle α of the strip relative to the main symmetry axes of the hexagonal ...
Helping to create the initial excitement associated with carbon nanotubes were Iijima's 1991 discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods; [11] and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, they would exhibit remarkable ...
Single-walled carbon nanotubes can be shortened in a scalable manner using oleum (100% H 2 SO 4 with 3% SO 3) and nitric acid. The nitric acid cuts carbon nanotubes while the oleum creates a channel. [6] In one type of chemical modification, aniline is oxidized to a diazonium intermediate.
Soon after, ensemble membranes consisting of multi-walled and double-walled carbon nanotubes were fabricated and studied. [4] It was shown that water can pass through the graphitic nanotube cores of the membrane at up to five magnitudes greater than classical fluid dynamics would predict, via the Hagen-Poiseuille equation, both for multiwall ...
A separate study conducted prior to the 2013 annual Society of Toxicology meeting aimed to identify potential carcinogenic effects associated with multi-walled carbon nanotubes (MWCNT). The findings indicated that, in the presence of an initiator chemical, the MWCNTs caused a much greater incidence of tumors in mice.
The study was undertaken to characterize the physicochemical properties of single-walled nanotubes (SWNTs), multi-walled nanotubes (MWNTs) and functionalized MW (MW-COOH and MW-NH2), and to assess their cytotoxicity in human astrocytoma D384-cells and lung carcinoma A549-cells, using the MTT assay and calcein/propidium iodide (PI) staining.