Compressibility and specific evaporation resistance of the monolayers of long-chain alcohols and glycol monoalkyl ethers

The monolayers of long-chain compounds such as cetyl and stearyl alcohols are being used extensively to minimize the loss of water by evaporation in reserviors. Permeability of water vapour through a monolayer depends on, among others, the magnitude of the van der Waals type of cohesive forces of the film molecule with its neighbours, and on the adhesive force between the monolayer and the water subphase. Further extension of the n-alkyl chain and/or suitable modification of the terminal polar group would, therefore, make a monolayer more effective in reducing evaporation