Bonding & Structure The Discovery and Application of Fullerenes F.6B Seto Ho Ki (10)
Introduction---Fullerene When does it discover? Who discover? What is it actually? 1985 Researchers at Rice University Rice University A family of carbon allotrope; molecules composed entirely of carbon, in the form of hollow sphere, ellipsoid, or tube.
Prediction & Discovery In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms. Scientists discovered C60, and shortly after came to discover the fullerenes. In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms. Scientists discovered C60, and shortly after came to discover the fullerenes.
More about fullerene Physical properties: hard, stable, heat resistant, high conductivity, soluble in many solvent, e.g. toluene & carbon disulfide. From the Chemical view: it is not totally unreactive due to its sp 2 -hybridized carbon atoms, bent to form closed sphere or tube.
Arc discharge > Nanotubes were observed in the carbon soot of graphite electrodes during an arc discharge. > Nanotubes were observed in the carbon soot of graphite electrodes during an arc discharge. > During this process, the carbon contained in the negative electrode sublimates because of the high temperatures caused by the discharge. > During this process, the carbon contained in the negative electrode sublimates because of the high temperatures caused by the discharge. Laser ablation > A pulsed laser vaporizes a graphite target in a high temperature reactor while an inert gas is bled into the chamber. > A pulsed laser vaporizes a graphite target in a high temperature reactor while an inert gas is bled into the chamber. > The nanotubes develop on the cooler surface of the reactor, as the vaporized carbon condenses. A water-cooled surface may be included in the system to collect the nanotubes. > The nanotubes develop on the cooler surface of the reactor, as the vaporized carbon condenses. A water-cooled surface may be included in the system to collect the nanotubes. Chemical vapor deposition (CVD) > During CVD, a substrate is prepared with a layer of metal catalyst particles. > During CVD, a substrate is prepared with a layer of metal catalyst particles. Synthesis of Carbon Nanotube
Safety Issue!!! Although C60 has been thought in theory to be relatively inert, a presentation given in March 2004 suggests that the molecule is injurious to organisms. Although C60 has been thought in theory to be relatively inert, a presentation given in March 2004 suggests that the molecule is injurious to organisms. An experiment is carried out which introduced fullerenes into water at concentrations of 0.5 parts per million, found that largemouth bass suffered a 17-fold increase in cellular damage in the brain tissue after 48 hours. The damage is known to impair the functioning of cell membranes. There were also inflammatory changes in the liver and activation of genes related to the making of repair enzymes. An experiment is carried out which introduced fullerenes into water at concentrations of 0.5 parts per million, found that largemouth bass suffered a 17-fold increase in cellular damage in the brain tissue after 48 hours. The damage is known to impair the functioning of cell membranes. There were also inflammatory changes in the liver and activation of genes related to the making of repair enzymes.
Applications Buckypaper > Used to illuminate computer and television screens if exposed to electric charge; more energy efficient. > Used to illuminate computer and television screens if exposed to electric charge; more energy efficient. > Heat sinks that would allow computers and other electronic equipment to disperse heat more efficiently. > Heat sinks that would allow computers and other electronic equipment to disperse heat more efficiently. > Exteriors of airplanes: Lightning strikes would flow around the plane and dissipate without causing damage. > Exteriors of airplanes: Lightning strikes would flow around the plane and dissipate without causing damage. > Protect electronic circuits and devices within airplanes from electromagnetic interference. > Protect electronic circuits and devices within airplanes from electromagnetic interference. > Serve as an extremely effective armor plating. > Serve as an extremely effective armor plating.
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