ABSTRACT
Monomolecular films have been effective in laboratory studies in reducing or inhibiting evaporation from water surfaces. This chapter reviews the work on monomolecular films. E. K. Rideal investigated the effectiveness of unimolecular films of stearic, lauric, and oleic acid in diminishing the rate of evaporation of water. In his experiment, the rates of evaporation from the film-protected surface were found to be much lower than those from a clean water surface. V. K. La Mer and T. W. Healy reviewed the subject of retardation of water evaporation by monolayers. They demonstrated conclusively that a compressed, molecularly oriented monolayer will be effective under field conditions. Small surface pressure gradients can cause significant changes in boundary layer properties and, consequently, in evaporation rates. Studies had shown that monomolecular films will change the temperature of the water surface, the reduced rate of evaporation giving rise to a surface warming.
