Carbon cloth was produced by temperature-programmed pyroloysis of commercial cotton cloth under an argon flow. The temperature program included a slow ramp of 0.5ЊC/min in the 150 to 400ЊC range, and 1ЊC/min from 400 to 600ЊC. These slow ramps cover the temperature range in which the major part of the pyrolitic chemical changes take place. The samples were then heated at a faster rate up

Certain microporous carbons have pores of molecular dimensions, the size of which can be adjusted over a wide range to fit the dimensions of a large variety of molecules. With knowing the dimensions of these molecules, size-calibrated porous carbons can be produced. In this work, we took advantage of the electronic conductivity of carbon in using it as an electrode in electrolytic solutions. By changing the electrode potential, we could induce electroadsorption and electrodesorption of ions of different dimensions into pore-calibrated carbons, thus enabling us to estimate effective ion sizes. A few fundamental questions such as whether ions accommodated in the electrodes' pores are in a solvated state, which is important for novel electrochemical energy storage devices and for microbiological systems, could be addressed. Analysis of the results indicates that all the cations that are employed are electroadsorbed in the electrode pores in hydrated states. Compared with the monovalent cations, the bivalent cations exhibit dimensions that make them almost twice as big. Monovalent anions are basically adsorbed in a nonhydrated state. The doubly charged sulfate anion is adsorbed in the hydrated state. The nitrate, a multiatom planar anion, has a smaller effective dimension than the monoatomic halogen anions, in accordance with the observation that the pores in many activated carbons are slit-shaped. The analysis of the results enabled us to establish a scale of ionic effective dimensions in aqueous media, as presented below (MTBE stands for methyl tert-butyl ether):  cations, [3.62 Å, N2] < Cs+ < K+ < Na+ < Li+ < [4.21 Å, CF4] < [5.05 Å, SF6] < [5.8 Å, MTBE] < Ba2+, Ca2+, and Mg2+; anions, [3.62 Å, N2] < NO3 - < Cl- < F- < Br- < [4.21 Å, CF4] < ClO4 - < [5.05 Å, SF6] < [5.8 Å, MTBE] < SO2-. We discovered that as long as the pore size is considerably greater than the ion size, the electric double-layer capacity at moderate concentrations is independent of both the size and charge of the ions in solutions.

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In an attempt to form a proton-selective environment in porous carbons that is similar to that of protonconducting polymers, we used highly oxidized molecular sieving carbons that are covered by oxygen-containing surface groups. Naturally, it would be assumed that the free electron pairs of the surface oxygen atoms are those that provide specific adsorption sites for protons. However, we discovered that selective adsorption of protons takes place within the pores of the molecular sieving carbon electrode, even in the absence of surface oxides.

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