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A self-assembled monolayer of 1-dodecanethiol (DT) was formed on a copper surface pretreated using different methods. The corrosion protection abilities of the monolayer were evaluated in an air-saturated 0.51 M NaC1 solution using various techniques including electrochemical impedance spectroscopy, polarization, coulometry; weight loss, and x-ray photoelectron spectroscopy. It was found that the corrosion resistance of the monolayer was improved markedly by using a nitric acid etching method. A minimum concentration of 10 M DT was needed to form a protective monolayer. The DTmonolayer retarded the reduction of dissolved oxygen and inhibited the growth of copper oxide in the NaC1 solution. In comparison with other inhibitors, such as benzotriazole (BTA) and mercapto-benzothiazole (MBT), the DT-monolayer showed much better corrosion resistance in aqueous solution.

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The adsorptive dehydration of aqueous ethanol using 3-Á molecular sieve adsorbent has been studied experimentally by following the uptake curves for a closed batch system and by measuring breakthrough curves for a packed column. This system is potentially attractive for the dehydration of rectified spirit in the production of fuel alcohol. The equilibrium isotherm is almost rectangular, and the kinetic data for both systems can be satisfactorily correlated in terms of simple kinetic models. The results of experiments in which particle size and fluid velocity were varied show that Intraparticle diffusion is the main resistance to mass transfer with some contribution from external film resistance at low fluid velocities and/or water concentrations.