Materials
Typical inorganic nanotube materials are 2D layered solids such as tungsten(IV) sulfide (WS2), molybdenum disulfide (MoS2) and tin(IV) sulfide (SnS2). WS2 and SnS2/tin(II) sulfide (SnS) nanotubes have been synthesized in macroscopic amounts. However, traditional ceramics like titanium dioxide (TiO2) and zinc oxide (ZnO) also form inorganic nanotubes. More recent nanotube and nanowire materials are transition metal/chalcogen/halogenides (TMCH), described by the formula TM6CyHz, where TM is transition metal (molybdenum, tungsten, tantalum, niobium), C is chalcogen (sulfur, selenium, tellurium), H is halogen (iodine), and the composition is given by 8.2<(y+z)<10. TMCH tubes can have a subnanometer-diameter, lengths tunable from hundreds of nanometers to tens of microns and show excellent dispersiveness owing to extremely weak mechanical coupling between the tubes.
In 2007, Chinese scientists announced the creation in the laboratory of copper and bismuth nanotubes.
Read more about this topic: Inorganic Nanotube
Famous quotes containing the word materials:
“Artists, whatever their medium, make selections from the abounding materials of life, and organize these selections into works that are under the control of the artist.... In relation to the inclusiveness and literally endless intricacy of life, art is arbitrary, symbolic and abstracted. That is its value and the source of its own kind of order and coherence.”
—Jane Jacobs (b. 1916)
“If our entertainment culture seems debased and unsatisfying, the hope is that our children will create something of greater worth. But it is as if we expect them to create out of nothing, like God, for the encouragement of creativity is in the popular mind, opposed to instruction. There is little sense that creativity must grow out of tradition, even when it is critical of that tradition, and children are scarcely being given the materials on which their creativity could work”
—C. John Sommerville (20th century)
“Young children learn in a different manner from that of older children and adults, yet we can teach them many things if we adapt our materials and mode of instruction to their level of ability. But we miseducate young children when we assume that their learning abilities are comparable to those of older children and that they can be taught with materials and with the same instructional procedures appropriate to school-age children.”
—David Elkind (20th century)