Carbon nanofibers and tubes

Carbon fibers

Carbon fibers are used in structural composites in aerospace, automotives, and sporting equipment, a strong fibre when added to polymer precursor. Here CNTs act as a nucleating agent for polymer crystallization to improves the polymer orientation. Incorporation of 1 wt % of nanotubes into polyacrylonitrile precursors can increase the tensile strength and modulus of the resulting carbon fiber by 64% and 49%, respectively. Plastics which are good electrical insulators, but they can be made to have electrical conductivity by loading them with conductive fillers, such as carbon black, Carbon nanotubes and graphite fibers. The natural tendency of Carbon nanotubes to form ropes provides inherently very long conductive pathways even at relatively low loadings.

Carbon nanotubes

Carbon nanotubes can be dispersed in polymers and epoxies to improve the compression, shear, and bending strengths, including stiffness, toughness, fatigue life, failure mechanisms and wear properties. Likewise nanotubes can be used to improve the modulus and toughness of elastomers and a wide variety of thermoset composite systems at loading levels of one percent or less. Carbon nanotubes blend well with plastics, and can impart reasonable conductivity at modest loadings. Carbon nanotubes have very high surface area (upto 1000 m2/g), good electrical conductivity, excellent chemical stability in acidic environments, linear geometry that makes their surface highly accessible to the electrolyte which are the desired intrinsic characteristics necessary for use as electrodes in batteries, capacitors (exceeding 100 Farads/gram), and fuel cells. Carbon nanotubes have the highest reversible capacity of any carbon material for use in lithium-ion batteries. Nanotubes could also have a significant impact on the biotech, pharmaceutical, and medical device industries. Nanotubes can be functionalized to target certain types of cells. Several research groups have published data demonstrating that nanotubes could be used as drugs or to deliver drugs to targeted cells. Nanotubes might also be used as miniature biosensors for drug discovery, diagnostics, detect small amounts of molecules through electrical, optical, or mechanical means to get specific information about targets for therapeutics.