New Forms of Carbon

Abstract

pyramidal inversion in the sulfonium ylide (43), AH* = 23.3 k c a l / m o l e [~~~l , is somewhat lower than that for sulfonium salts ( A H * = 25-29 kcal/ 'C2H5 431 mole) [9*,991, and much lower than barriers found in sulfoxides ( A H * = 35-42 kcal/mole) Although substantial (2p-3d), bonding is postulated t o occur in sulfoxides f1521, and, by extension, in sulfilimines, it [1511 D . Darwish and R . I . . Tomilson, J. Amer. chem. SOC. 90, 5938 (1968).is not clear at present whether the pyramidal stability of these compounds should be attributed to the effect of t h e x bonding, rather than to theeffect of theelectronegativity of the oxygen and nitrogen substituent or to lone pair-lone pair interactions.A number of novel carbon materials whose unique properties fit them for many uses have recently been developed. Pyrolytic graphites are excellent conductors of heat and electricity parallel to the surface, whereas they are semiconductors perpendicular to the surface. A similar anisorropy is found in graphite foils, which are impermeable, but also very flexible. Classlike carbon, which is also impermeable, is, however, completely isotropic. Carbon foams and felts are extremely light and exhibit very good thermal insulation up to high temperatures. In addition to very high strength, carbon Jibers have values of Young's modulus greater than that of any other fibers or wires. Carbon fiberiresin composites are therefore more rigid than any other known materials; their specific Young's modulus is five times that of steel.

SU-8 Photolithography as a Toolbox for Carbon MEMS

“…Different precursors to glass-like carbon exist, including phenolic resins, polyfurfuryl alcohols, cellulose, polyvinyl chloride and polyimides [43][44][45][46][47][48][49][50][51][52][53]; and the degree of shrinkage and carbon yield, the ratio of the weight of carbon to the weight of the original polymer sample, varies depending on the choice. For example, phenol-formaldehyde, polyfurfuryl alcohol and polyvinyl alcohol have the highest yields, with approximately 50% carbon.…”

Steady‐State Measurements of Vanadium Redox‐Flow Batteries to Study Particular Influences of Carbon Felt Properties

“…Carbon felts are well-established materials in thermal insulation applications, and their industrial introduction dates back to the late 1960s. [1] Due to their high electronic conductivity and large surface area, they were used soon afterwards in electrochemical synthesis, [2] water purification, [3] electrochemical analysis [4] or batteries. [5][6] With the resurfacing interest in redox flow batteries during the last few years, activities aiming at a deeper understanding and further improvement of these porous carbon materials have been intensified.…”

“…Carbon felts are well‐established materials in thermal insulation applications, and their industrial introduction dates back to the late 1960s . Due to their high electronic conductivity and large surface area, they were used soon afterwards in electrochemical synthesis, water purification, electrochemical analysis or batteries .…”

Conjugated one and two dimensional polymers

“…Unlike the case of polyacetylene, both cis configurations 16 and 17 have a smaller band gap than the trans configuration 15. Polypyridinopyridine (Vohler et al 1970, Brennan ations of polypyridinopyridine are 18 and 19. The band structure of 19 is given in figure 10.…”