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The kinetics of the sorption characteristics of seven different solvents has been measured at 22°, 40°, and 50°C in several cured epoxies. In addition to water, the organic solvents methanol, acetone, isopropanol, ethyl acetate, 1,2-dichloroethane, and toluene were examined. The resin, diglycidyl ether of bisphenol A, was cured with four hardeners, each one resulting in a different epoxy material. The curing agents include triethylenetetramine, nadic methylanhydride, dicyandiamide and m-phenylenediamine, all commonly used substances. Data were analyzed using Fick's diffusion equation. In general, three types of behavior were observed, Fickian diffusion, Case II diffusion, and anomalous diffusion. Fickian or anomalous behavior dominated at all temperatures. Diffusion was both material and solvent dependent. The anomalous nature of isopropanol was noted. Although chemically similar to methanol and about the same size, as acetone, isopropanol is sorbed at a much lower rate. A combination of physical and chemical effects appeared to be responsible for the observations in the epoxies. Diffusion coefficients were estimated for all penetrants and were mostly in the range of 10−9 to 10−11 cm2/s. Where appropriate, apparent activation energies for diffusion were calculated from the kinetic curves.

Studies of multiline ESR spectra in ten organic charge-transfer salts give g-tensors which are characteristic of individual molecular ions containing sulphur, nitrogen and smaller atoms. Such nearly universal g-tensors are not found in three salts with molecules containing selenium. These conclusions are supported by some results at variable temperature and hydrostatic pressure.

Etude de la structure electronique, et des proprietes de l'etat fondamental, des diphenyl-3,7- et bis(dimethylamino)-3,7-dithia-1,5 tetrazocines-2,4,6,8, par des calculs ab initio STO-3G (+5D), et par spectrometrie photoelectronique RX; interpretation d'une conformation du cycle «courbe» avec de fortes interactions soufre-soufre transversales au cycle

An effective chemiluminescence demonstration requiring minimal preparation based on the oxidation of oxalyl chloride by hydrogen peroxide.