The Materials Revolution

By the mid-80s it was clear to most researchers that success on the conductivity side had taken its toll on polymer processability. Attention turned back to restoring the solubility and mechanical properties of the polymer. Polyaniline received the most attention initially. The nonconductive emeraldine base form is soluble in A-methylpyrrolidone [28] and films can be cast. Subsequent doping with a protonic acid from aqueous solution, or in situ with a photo-acid generator [45], is necessary to achieve conductivity. Polyaniline is also soluble in sulfuric acid, not the most convenient of solvents. Nevertheless it proved possible to spin fibers [46], cast films and extmde sheets of conductive polyaniline sulfate, but the laboratory experiments did not make the transition into large-scale manufacmring. 

A major advance in the solubilization of polyaniline was self-doping by the attachment of a sulfonic acid side group to the backbone ring [47,48]. The resulting material is essentially a polyzwitterion with the acid proton transferring to the basic amine backbone. The polymer is then soluble in mildly basic aqueous solutions and can be coated over large areas. 

Almost simultaneously, another breakthrough occurred when it was realized that the protonic acid dopant could be selected or modified to act as a surfactant. Homologs of toluene sulfonic acid were the first examples examined [49], and camphor sulphonic acid proved to be one of the most interesting and promising acid surfactants [50], solubilizing polyaniline in m-creosol. 

by the mid-90s, the scientific foimdations were well established, and methods had been developed to overcome the difficulties of achieving both conduction and processability in the same material. Many potential applications had already been identified and patents filed. New companies were started and more established companies initiated new business units, both on the supply side as vendors of the materials and on the demand side as developers of technological applications. Naturally, most of this work was hidden behind closed doors and presentations were aimed more at venture capitahsts than at the scientific community. Publicity was generated, not by talks at scientific conferences, but rather by carefully managed press releases. The subsequent history is probably better documented by a business analyst than by a scientist. 

The scientific story, however, does not end there. The identification of new potential applications demanded modifications and improvements in the materials, which in turn revealed more interesting and possibly usefiil properties. In 1993, Joel Miller, who had 

Twenty-five years ago, Stanford s William Little startled the general public with his predictions of plastic materials that had no electrical resistance at high temperatures, room-temperature superconductors, flying carpets, superconducting skis, trains that levitated over tracks and glided smoothly along at 300 miles per hour, and frictionless electrical transmission lines. 

He even came up with a theory to explain how such materials would work and suggested that superconductivity might even be possible at temperatures upward to 3,632° F. His notions were published in Physics Review Letters, one of the most respected physics journals, and in Scientific American, the forum for the communication of a scientist s work to other scientists of different disciplines. 

Little s ideas were intriguing to anyone who delighted in science fiction, but a source of dismay for his scientific colleagues. Lamented the New Scientist in London It is highly disappointing that the possibility of a room-temperature superconductor has been removed. The technological 

The situation today is vastly different. Consider Time magazine s report of a recent superconductivity meeting of the American Physical Society in New York City  

They began lining up outside the New York Hilton s Sutton Ballroom at 5 30 in the afternoon by the time the doors opened at 6 45, recalls physicist Randy Simon, a member of TRW s Space and Technology Group, it was a little bit frightening. There was a surge forward, and I was in front. I 

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Polymers are at the forefront of the materials revolution their uses are expected to grow at a faster rate (-15% per year) than that of any other structural compound. This trend may even be accentuated as polymers with new functionalities appear. We shall discuss here polymers having electrolyte properties for which important applications are foreseen. 

Vitamin D [1406-12-2] is a material that is formed ia the skin of animals upon kradiation by sunlight and serves as a precursor for metaboUtes that control the animal s calcium homeostasis and act ki other hormonal functions. A deficiency of vitamin D can cause rickets, as weU as other disease states. This tendency can be a problem wherever animals, including humans, especially kifants and children, receive an kiadequate amount of sunshine. The latter phenomenon became prevalent with the advent of the kidustrial revolution, and efforts to cute rickets resulted ki the development of commercial sources of vitamin D for supplementation of the diet of Hvestock, pets, and humans. 

Clearly, not all forms of earbon material, nor all the possible applieations thereof, are diseussed in this book. However, the applieation of earbon materials in many advaneed teehnologies are reported here. Carbon has played an important role in mankind s teehnologieal and soeial development. In the form of charcoal it was an essential ingredient of gunpowder The industrial revolution of the IS and 9 eenturies was powered by steam raised from the burning of eoal New applieations of earbon materials wiU surely be developed in the future. For example, the reeently diseovered earbon nanostruetures based on C q (closed eage moleeules, tubes and tube bundles), may be the foundation of a new and signifieant applieations area based on their superior meehanieal properties, and novel eleetronie properties. 

These kinds of maps and optimisation approaches represent impressive applications of the quantitative revolution to purposes in materials engineering. 

This whole field is an excellent illustration of the deep change in metallurgy and its inheritor, materials science, wrought by the quantitative revolution of mid-century. 

However, I believe that enough has been described to support my contention that modern methods of characterisation are absolutely central to materials science in its modern incarnation following the quantitative revolution of mid-century. That revolution owed everything to the availability of sensitive and precise techniques of measurement and characterisation. 

Natural rubber can be obtained from the sap of a number of plants and trees, the most common source is the Hevea brasiliensis tree. Although natural rubber was known in Central and South America before the arrival of Christopher Columbus in 1492, the first use as an adhesive was established in a patent dated in 1891. As rubber became an important part of the industrial revolution, the rubber adhesives market grew in importance. To comply with the increasing demand on natural rubber materials, plantations of Hevea brasiliensis trees were established in southeast Asia in the early 20th Century, mainly to supply the demand from the automobile industry. 

John F. Judge, Composite Materials The Coming Revolution, Airline Management and Marketing, September 1969, pp. 85, 90, and 91. 

Each interferon preparation was ultracentrifuged at 20,000 revolutions per minute for one hour to remove tissue debris and inactivated virus. The supernatant was dialyzed against distilled water (1 400) for 24 hours at4°C. The material was then freeze-dried. The dried product was reconstituted in one-tenth of the original volume in distilled water and dispensed into ampoules. Reconstituted solutions were assayed for interferon activity, examined for toxicity, and tested for sterility. 

As humans entered the Bronze Age, charcoal was the only material that could simultaneously heat and reduce metallic ores. Later, the addition of an air blower made it possible to achieve temperatures high enough to soften or melt iron. During the Industrial Revolution, charcoal was largely displaced in most ironworks by coke derived from coal. However in Brazil, which lacks adequate coking coal resources, most of the charcoal produced is still used to reduce iron ore. 

Although chemistry as an emperical fundamental didpline has a long history, its application in industry gained importance after the introduction of the use of fossil energy sources during the industrial revolution. The chemical industry withdraws non-renewable materials, mainly fossil oil, from the earth s reserves to use as an energy source and as fossil oil a source of raw materials for production processes. The products so produced are rather... 

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