Stronger than Steel

Rigid bones are needed for kinetic motion, support of internal organs, and muscle strength. The bones that compose the human thigh are pound for pound stronger than steel. Nature meets these needs by separating the skeleton into several bones and bone systems, creating joints where the bones intersect. 

FIGURE 19.16 The material used to make this high-performance car protects the driver by making use of a design like that of the mollusk shell in Fig. 19.15. The car is made of composite materials that are stronger than steel. 

Carbon in the form of graphite is soft and malleable at the nanoscale, carbon can be stronger than steel and is six times lighter. 

A portion of the stmcture of Kevlar. Pound for pound, this polymer is stronger than steel, and it has excellent flame resistance. 

Carbon reinforced products that require less energy to produce and that are ten times stronger than steel, lighter than aluminum, and that conduct more heat than copper can be increasingly used to reduce the weight of vehicles, improve the performance of appliances and tools and increase the efficiency of heat-transfer systems. Other forms of carbon will provide super semiconductors and advanced optics. 

Kevlar a polymer fiber that is stronger than steel, but very light. It is used to make bullet-proof vests and other body armor. 

Kevlar, a polymer, is a special kind of fiber that is five times stronger than steel, and it is used to make body armor and sports equipment. 

The early work focused on a particular silkworm, Bombyx mori, that lives on mulberry bushes. There are other silkworms each with its own special properties, but in general most silk is still derived from the original strain of silkworm. Crystalline silk fiber is about four times stronger than steel on a weight basis. 

Dense, lightweight, anticorrosive metal stronger than steel used in aircraft engines titanium dioxide used widely in paints and plastics. 

A spider s orb-web is formed by extrusion of a concentrated protein solution and stretching of the resulting fiber. The cross-strands, which are stronger than steel, resemble silkworm silk. The molecules contain microcrystalline p sheet domains that are rich in Gly-Ala repeats as well as polyalanine segments. The capture spiral is formed from much more elastic molecules that contain many -tum-forming sequences. These assume a springlike p spiral. See Box 2-B. 

Kevlar, a polymer of aromatic amides, is several times stronger than steel, but much fighter and also fire resistant. Kevlar fibers are formed into hollow cylinders that are then woven into fabrics useful in bullet-proof vests and manufacture of automobile tires, see also Cellulose Polyesters Polymers, Synthetic. 

Because of their diverse structure, one-third of the tubes are expected to possess metallic character and the remaining two-thirds to behave as semiconductors [2, 3]. CNTs represent potential candidates to be used in field emission [4-6] and nanoelectrical devices [6-10], components of electrochemical energy [11, 12] and hydrogen storage systems [13, 14] and as components in composite materials [15-17]. They represent the ultimate carbon fiber, exhibiting exceptional mechanical properties [18-21] by being up to 100 times stronger than steel [22]. 

In 1991, yet another carbon allotrope was discovered. Hexagons of carbon atoms were made to form a hollow cylinder known as a nanotube. A nanotube has a diameter about 10 000 times smaller than a human hair. Despite its thinness, a single nanotube is between 10 and 100 times stronger than steel by weight. Scientists are currently experimenting to find ways in technology and industry to use the unique properties of nanotubes. 

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