INTERFACIAL MASS TRANSFER - PERMEATION OF CONDENSED MONOLAYERS

The density-fluctuation and energy-barrier theories for the permeation of condensed monolayers are examined. If the entropy changes associated with fluctuations in the local monolayer density are properly evaluated, the former theory is valid for water evaporating through a 1-eicosanol monolayer at 25° C. and 22.4 dynes per cm. surface pressure. The latter theory is invalid if, following Goodridge and Robb, the transition state is chosen as the permeant molecule having lost one translational degree of freedom to motion along the reaction coordinate. The rate constant for mass transfer across the uncontaminated gasliquid interface is derived from transition-state theory for the special case where deviations from the perfectgas law and Henry's law are negligible. © 1969, American Chemical Society. All rights reserved.